Posted By: jstoob 235 Plugs and distributor (very long) - Wed Jan 08 2020 03:29 AM
Hello all, longtime lurker, first time poster. I humbly post to Stovebolt where I hope someone can help me out. I have taken my truck to two mechanic shops which have failed to fix the problem permanently.

About the truck: 1950 Chevy 3100. It had sat for 20 years outside, been stolen once, and restored sometime in the 70's or 80's. Based on the valve cover, and the serial number stampings on the side of the block and head, I believe I have a late model 235, sometime between 58-62 is my best guess.

About me: Aircraft mechanic for the Air National Guard, but not a vehicle mechanic per se, unless you count the Youtube Academy and forum lurking. I've tried to do as much as I can on my own to learn and save some $$$.

Here we go:

I bought the truck sitting in a storage yard where it had been sitting for at least eight years. It had the aforementioned inline six, with a stock single barrel carb and a newer, unidentified alternator on it, and had what we thought was a Buick ignition coil (going of serial #'s) on it. After getting it on tires to get it rolling, myself, with the help of others did the following: brand new fuel tank, purged fuel lines, new points, new condenser, new plugs, new wires, new rotor cap, and oil change. At this time we attempted to start the vehicle, it was turning freely, and after finally getting everything in the right place, it fired up. It ran like a top, the best way to describe it was it sounded like a sewing machine--quiet, low RPMS, very smooth and pleasant sounding. After some brake work, we drove it around town and it ran very nice. After a little more work on the brakes (front disc conversion) I took it to a mechanic in town to have them bleed the brakes better than I, and look everything over for safety's sake. I picked it up on a Friday afternoon the weekend I was moving out of state. Almost immediately I noticed it was running extremely rough and would only run if it was taking on a lot of fuel, and even then it sounded terrible. Instead of leaving it behind for the mechanic to go over again, I took it with on the move. I called the shop up, told them the issue, and they said they hadn't messed with any throttle settings but recommended I check the accelerator pump in the carb. I then rebuilt the carb with a Mike's Carburetor kit and instructions and still had the same issue--real rough running, not holding idle, only running with a ton of fuel. Around this time I upgraded the unknown alternator with one from a '79 Chevy pickup.

Now in Denver, I tried to think of what could be causing it. I replaced the Rochester single barrel with a Weber 32/36 from Langdon's. (I briefly tried to explain the issue to Tom, but the more I talked the more flummoxed he got) Still having the issue after the new carb, I put on a new fuel pump that had the recommended flow, per Weber/Landon's specs. I checked vacuum advance, looked for vacuum leaks, valves not opening or closing. Nothing appeared off. I then took it to a mechanic here in Denver. After a few days they called back and said the truck was ready. I went in and they said they checked compression and timing, both were good. There was a loose bolt here and there, but nothing funky. They changed contacts, coil, and spark plugs. We went out to the shop and it was running just like it had when we brought it back to life--like a sewing machine, nice and quiet, and very healthy sounding. I asked if that was really all it took, swapping coil, plugs, and contacts and they said yes. I didn't understand but thought maybe I overlooked something.

I was ecstatic regardless, I drove it around all night, then the next day we took it to lunch in Morrison (20 minutes from where I live). It made it to lunch fine, still running smoothly, but on the drive back it started feeling funny again. By the time we had made it home, and since then, it has gone back to rough running. Will not hold idle without gas, and generally doesnt sound right. (Still dealing with that shop on a refund or a "fix") I pulled the spark plugs and they were covered in black soot already. I cleaned what I could off the spark plugs thinking if I got them clean again it should run like a top again. Unfortunately, it still ran poorly. Not holding idle, not running like a sewing machine. I tried messing with idle speed on the Weber, but it really did nothing different.

So, as the title says, I guess I'm back to plugs and the distributor; perhaps the coil as well. Could it be I'm frying spark plugs somehow? Is the distributor not functioning properly? Is the coil too hot? Is the condenser incorrect? Is the alternator incompatible? Do I just have the wrong darn spark plugs? At this point I'm thinking about swapping over to HEI or something to eliminate one more thing, but I don't want to continue throwing parts at it (even if that would be an upgrade).

Would appreciate any help or suggestions you fine folks have. At this point I don't know what to do otherwise.

Many thanks,
Jared in Denver
Posted By: baldeagle Re: 235 Plugs and distributor (very long) - Wed Jan 08 2020 06:31 AM
Alright. Now think about what you wrote.
Originally Posted by jstoob
would only run if it was taking on a lot of fuel,
. Engines run on a mixture of fuel and air that is ignited by a spark to create an explosion. Too little fuel, or too much air, and the engine won't run well at all. You statement is screaming "vacuum leak". There's air getting into the fuel system somewhere that's screwing up the fuel/air ratio causing the engine to run bad.

Now, think about the sequence of events. You sent the truck to a mechanic to work on the brakes. That has nothing to do with the fuel system. However, if he was working in the engine compartment, he could have easily caused a vacuum line to slip off and cause your problem.

When you got to Denver, you got snookered by mechanics who either don't know what they're doing or are deliberately cheating you. You stated
Originally Posted by jstoob
new points, new condenser, new plugs, new wires, new rotor cap
, yet they replaced the points, coil, and spark plugs. They were already new. How would changing them fix anything?

Next, you state that the spark plugs are covered with black soot. This is an indication of too rich of a fuel/air mixture, which is the exact opposite of a vacuum leak.

Nothing irks me more than people replacing brand new parts simply because they don't understand how to troubleshoot. You don't need another coil, points, or anything else, although you may have to replace the plugs depending upon how badly they were fouled.

Based on your symptoms, you may have a combination of problems, but they are all fuel/air related. There's nothing wrong with your ignition system (coil, condenser, plugs, wires, distributor.)

Here's what you need to do.
  • Look for vacuum leaks while the engine is running (you do this by spraying carb cleaner around every vacuum nipple, at the base of the carb where it mounts to the manifold, and anywhere else that air can get into the engine other than the air horn of the carb, where it's supposed to come in. If the engine speeds up, you've found a leak. Do not stop looking if you've found one. There may be more.
  • Look at the spark plugs. Are they wet? You have unburned fuel. Are they covered in black charcoal (dry)? You're running too rich. They should be a light chalky brown after many miles of service.
  • Look at the choke plate. Is it closed almost all the way? What happens when you open it with your finger? Does the idle smooth out? How about if you push it closed? Does the idle smooth out? Adjust the choke. Make sure the choke mechanism moves freely throughout the length of its travel and is not hanging up at any position.
  • Check every rubber hose that feeds vacuum to something (like the advance on the distributor) for cracks by spraying it with carb spray. If the engine speeds up, you've found a leak. Replace the hose.

If none of that helps, replace the plugs, do nothing else, and see if that solves the problem. If it does, yet it reoccurs, go back to the list until you find the problem.

Whatever you do, do NOT replace or rebuild the carb. It's brand new. If you find a vacuum leak at the base of the carb, take if off and inspect the gasket. Place if over the manifold opening. Does it cover the intake holes at all? Does it sit flush with the manifold mount? Next, place it on the base of the carb. Does it restrict the area where the fuel dumps into the manifold? Is it missing a hole that allows fuel to enter through the accelerator pump? Does it sit flat against the base of the carb sealing it?

All of these things could be issues. Once you have verified something, you do not need to verify it again. One of the biggest things that drive people nuts is going over the same ground over and over again. Do each check carefully and then, once you've verified that it's not causing the problem, do not revisit it. The problem is elsewhere. Persistence is your friend.

If, after all this, you still have problems, come back and describe precisely what the symptoms are at idle and at speed. Does it just run rough? Does it stall at idle? When you step on the gas, does it bog down? Does it shudder? Does it die? Be precise. It matters.
Posted By: SimS Re: 235 Plugs and distributor (very long) - Wed Jan 08 2020 12:51 PM

I can go along with your diagnosis, but why does it run "like a sewing machine" for a period of time before it runs like crap? If it is a vacuum leak I would think the leak would be present at all times. The thing that I can't figure out is that it has had two carburetors {one old and rebuilt and one brand new) and the symptoms turn out the same. Almost sounds like some sort of heat related vacuum leak not associated with the carburetor itself. Let's see what the OP finds after going through your checklist.

Posted By: Dragsix Re: 235 Plugs and distributor (very long) - Wed Jan 08 2020 02:51 PM
There is a little low hanging fruit you can mess with here. On the carb issue, I myself am not a fan of the single weber. Pairs yes, but a single in place of the stock one bbl no.But you are stuck with what you have I guess. Also, I have generally found that the ported vacuum advance port on the weber is not sufficient to actually allow the stock 235 vacuum advance to work properly. So just asking, how many turns out on your mixture screw are you on the weber and how may turns out on your idle screw. The webers are very sensitive in that regard and may require an idle air jet change.

Plugs, which are you using? The 235s use an extended tip type. I have always run champions (43 years). J12YC, J14YC or the resistor versions RJ12YC and RJ14YC.

Is the clamp on the distributor tight? Is the bolt on the octane selector plate tight and is the hash mark on the octane selector set to zero with the hash mark on the distributor pad? Really what you are checking is whether the distributor is moving (it should move when the advance moves it) but not because its loose. Also, can you confirm that the diaphragm in the vacuum advance canister is holding and not ruptured?

Spark plug wires, take a look and make sure they are not laying across one another and cross firing.

Is the firewall ignition resistor in place and wired correctly to the coil?

Just a couple of things to check and get out of the way. Now if you don't know how to do some of this your self, now is a great time to buy a few basic tools, roll your sleeves up and dive in. Lots of help here.
Posted By: glenns towing Re: 235 Plugs and distributor (very long) - Wed Jan 08 2020 02:53 PM
You mentioned loose bolts here and there? Double check around the intake gasket area with carb cleaner when its running bad. Are the bolts tight there? Gasket damaged? It might take specific circumstances to get the veh to run like crap. Heat changes things.
Posted By: Wrenchbender Ret. Re: 235 Plugs and distributor (very long) - Wed Jan 08 2020 03:25 PM
You are building up carbon on the plugs causing the engine to miss fire. It is obvious your mixture is too rich. You need to fix a carb. that will run the correct mixture. I would mess with the original model B. They are simple & easy to work on. The usual problem with them is the power valve staying on all the time. There is a lot of posts on this in this website. Do a search. It would pay you to get a cheapy spark plug sand blaster & clean those plugs up instead of buying new ones every time they get carbon on them. You need compressed air to use it.
HEI would help as it fires a dirty plug better then conventional ign. That would not solve the problem though.
Posted By: jstoob Re: 235 Plugs and distributor (very long) - Wed Jan 08 2020 03:43 PM
At work now, reading through all these, thought I'd answer a few responses. Thank you for all of those by the way. I am planning on working on the truck tonight with your responses. I had read numerous posts regarding a vacuum leak around the carb on here and other places. I have had someone ever so slightly holding the gas pedal down to keep the engine running and sprayed carb cleaner around the carb base (both with the Rochester and the Weber) and did not hear any variation in the engine speed. I also tried to spray a little around the intake manifold, and a couple other places I might have a leak and I didn't notice anything there either. If memory serves correct, the new Weber came with a new gasket to go on the manifold. I will again attempt to see if I can stabilize the idle and spray again, just to see if my installations were correct. It would be a mild surprise that I had a vacuum leak considering of how well it ran for a day, then degraded, unless the shop had somehow plugged a leak without knowing and it rattled loose. The spark plugs were black and sooty after only 40 miles or so. I figured it was running rough, so I cleaned them up and put them back in, ever so slightly better sounding, but overall, still rough. At this point, I should change out every vacuum hose on the engine. I should have done that in my initial work but will track down some hose and just replace everything for peace of mine. I do have a manual choke, and will check the cable adjustment on that when I get home.

@SimS, I'm not sure if sewing machine is the right way to word it, but for the times its been running well, it sounds like a smooth and quiet sewing machine. The rest of the time when it's running poorly it sounds rough. It ran fine when I picked it up, and apparently slowly degraded.

@Dragsix I will check Weber's settings and try and reset the carb to their suggested settings. I can say that it ran very well twice throughout the high altitude with no changes on my part, From the Friday afternoon I picked it up it was humming just fine, and by late Saturday afternoon the performance had diminished without messing with anything. I will buy some Champions, which ones should I use, resisted or non-resisted? I would like to get a known working spark plug. If nothing changes, I'll have at least eliminated that. I have checked vacuum advance and it is not ruptured. I did find a replacement, swap it in, and had no change. Both felt to give about the same resistance. I will check the clamp on the distributor, but I believe the carb advance is working. I will also check wire arrangement... in fact, I'll take a picture for all to see if that helps. The ballast is new and should be wired correctly but I will check that as well tool.

@glennstowing The shop mentioned a loose bolt on the starter and a couple other places I cant remember now. Starter is touchy, but works. (Floor type still)
Posted By: Squire Re: 235 Plugs and distributor (very long) - Wed Jan 08 2020 04:27 PM
Quick kills are :
1)check vacuum advance travel in distributor. Check for smooth unimpeded travel
And operation...make sure any other vacuum leaks have been remedied first..
2) condenser failure...... today’s junk fails often!
3) distributor hold down clamp and bolt....... stove bolts often loosen causing
Timing issues
Posted By: Hotrod Lincoln Re: 235 Plugs and distributor (very long) - Wed Jan 08 2020 04:45 PM
Shotgunning parts at a problem without adequate diagnosis just increases the chances for creating more difficulties, without solving the original problem. Unfortunately, the type of structured maintenance protocols that aircraft systems have do not exist in the automotive world. Back when I spent some time doing USAF electronic maintenance, once the degree of difficulty on anything aircraft-related got beyond swapping minor components and twisting safety wire, everything went back to a maintenance depot or the factory for repair. Very little actual diagnosis or rebuilding got done- - - -we were just parts changers. I doubt that things have changed much since I went back to fixing cars 40-something years ago.

Your sooty spark plugs are a symptom of a flooding carburetor. Dump the Weber off a bridge with a deep river underneath, and go back to the right carburetor. I'm partial to Carter, but a few people still use a Rochester for something other than a paperweight.

Edit: Ed Pruss is in your area. Once you make 2 or 3 more posts and have access to the private message system, drop Ed a PM- - - -he can probably solve your problem in a matter of minutes.

Posted By: 68ironhead Re: 235 Plugs and distributor (very long) - Wed Jan 08 2020 04:51 PM
Vacuum leak under dash at wiper motor ?
Posted By: tclederman Re: 235 Plugs and distributor (very long) - Wed Jan 08 2020 05:09 PM
"Dump the Weber off a bridge with a deep river underneath, . . . " nono (the EPA might be watching, Jerry)

It is hard/useless to argue with your unfortunately-factual point of view (based on many observations/experiences).

The 261 in my Suburban has an AA1 GMC truck carburetor.
The old/original Rochester was a "tearful weeper". I needed a "larger" carburetor, anyway.

However, I have non-weeping dual Rochesters on another 261 in a 1954 Chevrolet pickup that I traded to a friend. It has run nicely for almost 20 years.

I am going to take a gamble on the non-leaking original Rochester on my 1954 235 Hydra-Matic. That carburetor was rebuild/inspected by a pro. It did not leak, and it worked nicely, on the rebuilt original 235 during break-in after a professional engine-rebuild.

I am hoping to keep that Rochester - for historical purposes. I think is is the first year a Rochester with an automatic choke ("stove pipe style") was standard equipment on a light Chevrolet truck? If I have to use a different carburetor I will not be surprised, and, it will not surprise me.
Posted By: baldeagle Re: 235 Plugs and distributor (very long) - Wed Jan 08 2020 06:28 PM
Originally Posted by SimS

I can go along with your diagnosis, but why does it run "like a sewing machine" for a period of time before it runs like crap? If it is a vacuum leak I would think the leak would be present at all times. The thing that I can't figure out is that it has had two carburetors {one old and rebuilt and one brand new) and the symptoms turn out the same. Almost sounds like some sort of heat related vacuum leak not associated with the carburetor itself. Let's see what the OP finds after going through your checklist.


You raise a very good point, which got me to thinking of something else. These old engines sometimes had problems with vapor lock due to the fuel lines being too close to the engine. It wouldn't hurt to check the fuel line to make sure it's not too close. The fuel lines were usually run through standoffs that bolted to something so that they couldn't get bent too close to the head. The problem was often at the front of the head where the line wraps around the motor to lead back to the carb.

Another possibility is that the carb is slightly warped, and as it heats up, the distortion of the metal causes it to begin sucking air in at the base.

The odd thing about his symptoms is that he initially describes what sounds like a classic vacuum leak, but then when he gets to Denver, he's obviously running over-rich. Two descriptions that are at complete odds with each other. That's why I suggested he may have more than one problem.

Jerry's suggestion is a good one. If Ed is available, he can probably sort it out pretty quickly.

The key to situations like this is to eliminate things one at a time. Once you have verified that something is not the problem, don't keep going back to it again. That will drive you nuts.

68ironhead points to a little-thought of issue. Sometimes there are vacuum connections in places you'd least expect them, like the wiper motor, and people seldom even think of those or else they assume it's OK. Never assume anything is OK until you've checked it out and verified that it is.

Some of the advice he got from professional? mechanics is nuts. What does the accelerator pump have to do with a rough idle? Again, mechanics are just guessing. They clearly don't even know that an accelerator pump is only used during - wait-for-it - acceleration. Sheesh.

Here's some things to think about. The problem occurred before he changed the carburetor. "would only run if it was taking on a lot of fuel" After he changed the carb, he had the exact same symptoms - "Will not hold idle without gas"

So, changing the carb changed nothing. Therefore, it's not the carb, although changing the carb could have introduced a second problem. He doesn't know if the plugs were fouled in his original location, because he never checked them until Denver. So, what sort of condition could cause the engine to need additional fuel to keep running yet fouls the plugs from too much fuel and is not related to the carb? Any time a motor needs additional fuel just to keep running, it's getting too much air. But, how does that foul the plugs?

If it were me, the first thing I would do is change the plugs. If it runs fine, then you know the poor running is caused by fouled plugs. Then you just need to figure out what's fouling the plugs. Obviously, it's too much fuel in the compression chambers. There are several things that can cause that; maladjusted carb, too high a pressure fuel pump, blocked air passages screwing up the fuel/air mixture, carb adjusted to overcompensate for a vacuum leak, a weak spark that prevents all the fuel/air mixture from being consumed.

Of course, all of this assumes that he's buying the right parts to begin with.

Posted By: Hotrod Lincoln Re: 235 Plugs and distributor (very long) - Wed Jan 08 2020 08:01 PM
Carburetors calibrated for elevations close to sea level also run RICH at Denver's altitude, since a carb mixes fuel and air by weight, not volume and the air at 5K+ feet isn't as dense as it is at lower elevations. Running a main jet a step or two leaner is probably a good idea, but looking for different jets for the Weber is probably going to be like finding a chicken with lips.
Posted By: jstoob Re: 235 Plugs and distributor (very long) - Wed Jan 08 2020 08:42 PM
One more clarification post to help with the troubleshooting. When we brought the truck back from the dead (In Lincoln, prior to the move), it ran smooth when we first fired it up with the Rochester. After a while it just ran like crud and not smooth anymore. I remember pulling the original plugs, and saw nothing noteworthy, but we put new ones in anyways. I will circle back on the wiper motors for a leak. Is there a manual somewhere I can find ID/OD of hose sizes? I have listed the plug & wires I bought below to see if those were incompatable in the first place.

Overall, its mind boggling that I could drive it around a couple times in Lincoln without issue and it got worse the more I drove it. Then, when picking it up from the mechanic in Denver, it ran smoothly all Friday night, ran smooth Saturday morning, then degraded into rough running. If all they changed was plugs, wires, coil, and it ran smoothly for a while, it made me wonder if one of those was wrong. Heck, is one wire backwards somewhere screwing it up? I will post a picture when I get home, maybe a keener eye than I will spot a really easy fix.

First plugs and wires:

Wires: Belden BEL 700126
Plugs: ACDelco AC R43
Posted By: EdPruss Re: 235 Plugs and distributor (very long) - Wed Jan 08 2020 10:20 PM
At our altitude we also lean out the idle jet, advance ignition, no pinging though.

Posted By: Dragsix Re: 235 Plugs and distributor (very long) - Wed Jan 08 2020 11:29 PM
Either the J12YC or the J14YC. Either will work fine, whichever is easier to get. Skip the resistor plugs. What I found with those webers is that the ported vacuum for the vacuum advance does not provide enough signal. Keep in mind that the original carb used ported vacuum for the advance, that is the port was to atmosphere (above the throttle blade). When the throttle blade began to open, vacuum built as the air passed the port, allowing the advance to start opening, reached max signal and max vacuum advance, and then tapered off as the throttle blade opened fully, eliminating the vacuum advance. So with a stock carb, when you gave the gas a rap at idle, the distributor would move quite a bit. Because the port is ported vacuum, you can set the timing at idle without disconnecting the advance line because there is no vacuum (or very little) to the advance unit at idle.

With the webers, the insufficient signal from the weber's vacuum port impedes proper advance. So generally you have to run the advance line to full manifold vacuum (where the wiper motor hose is). Thus, you set the timing with the vacuum hose disconnected and after reconnect the hose.

As for jetting, couple of places sell them, Redline, Sterling, same jets as the 32/36 and 38/38 weber. Keep in mind that for the Weber, there is an idle jet and an idle air jet. Both play a part in idle mixture. Also emulsion tubs but you dont even want to go messing with them unless absolutely necessary. The mixture screw only adjusts for volume. So if the idle jet is too large, and the idle air jet is too small, it will always run rich no matter how much you turn the mixture screw in. Worse, the main jetting plays a part on the off idle circuit with these webers, which in turn affects the quality of the idle fuel. They are very adjustable, but you need a good bit of patience to tinker with them. I am still learning with my dual 38/38s and I won't lie, the curve is steep and sometimes frustrating.

If you really want to get this truck running well, at least in my opinion, I would get back to basics. Put the single bbl carb back on (confirming that the power piston is not sticking), or get a Carter replacement carb (I always had very good luck with the YF's) and start from that point as those carbs were designed and engineered for these motors. Then fresh plugs, and just for giggles and because they are cheap, replace the condenser. As a couple of the fellas here have noted, today's stuff can be junk right out of the box.

Then confirm your timing, adjust the carb, and start from that basic point. Like I said, I myself am not a fan of a single weber on a 235 single bbl manifold. I am not saying that is your problem, but too many rabbits going down too many holes, in my view anyhow.

Posted By: 52Carl Re: 235 Plugs and distributor (very long) - Thu Jan 09 2020 12:10 AM
I'm with HRL. You need a nearby Stovebolt guru to spend 32 minutes to find out what is going on with your poor running engine issue. (If its HRL, it will take an extra 23 minutes because he talks slower. smile )
It is my opinion that you have had more than one issue going on at the same time. This is the most challenging of situations to diagnose in person, let alone trying to do it via keyboard..
What you have had done in an attempt to fix it may have added one or more problems, complicating things further.
This is why "Test, don't guess." is brought up on this site so often. (Thanks to HRL.)
Mine is, "Its never the carburetor."
Carb King Jon once stated, and I paraphrase, "Apparently the updraft carburetors were much more reliable based on how many rebuild kits we sell." He went on to state that the reason why he didn't sell many updraft kits was because that carburetor was difficult to remove, therefor the mechanic instead, worked on the issue which was actually causing the problem.
Posted By: jstoob Re: 235 Plugs and distributor (very long) - Thu Jan 09 2020 12:53 AM
Thank you for your responses. Here is what I did after work:

Test fire, would barely start, and only with the pedal applied to keep it running, will not idle by itself.

Installed six new J12YC plugs. The six I removed were heavily covered in soot, especially for only running 40-50 miles and for three hours. It's running rich, I see that.

Test fire, smoother, but still not holding idle, and still not running right.

Go to carb, return idle advance to just making contact, then 1 1/4 turns in. Then turn idle mixture all the way in, and back out two turns.

Test fire, no change.

Check distributor. Vac advance screw is slightly loose, and octane selector not at 0. New hardware for the screw to tighten, set octane selector to zero.

Test fire, no change.

Back out mixture screw 1/2, test fire, 1/2 again, test fire. No change.

Disconnected vacuum advance and sucked on it, I was able to turn the dizzy slightly.

If anyone sees a "hey dummy" in the picture below I'd be happy to feel stupid for a while if it meant it got fixed.

Again, thanks for all the help.

Posted By: glenns towing Re: 235 Plugs and distributor (very long) - Thu Jan 09 2020 01:17 AM
Oh didnt realize loose bolt was a starter issue. Check em anyhow. Not to much mention on the timing. I would look there also. Different carbs with the exact same problem??? Very unlikely, but yet possible. Verify timing and advance functions as well. Wont cost nuttin but time. Test dont guess... No black smoke, indicating a rich condition? But yet, fouls plugs in 40 miles. Hmmm
Posted By: Hotrod Lincoln Re: 235 Plugs and distributor (very long) - Thu Jan 09 2020 02:52 AM
Did the shop that sold you the Weber explain that you'd probably need a fuel pressure regulator also? They're notorious for flooding with even a tiny bit too much fuel pressure. If you're going to stubbornly stick with that carburetor, you'll have to spend more money- - - -get the fuel pressure down to 2-3 PSI or it will never quit flooding. Also, install a VERY good quality fuel filter- - - -not one of those Mickey Mouse see through things- - - - -even microscopic bits of dirt or debris will make a Weber flood.
Posted By: jstoob Re: 235 Plugs and distributor (very long) - Fri Jan 10 2020 01:40 AM
Nothing so far has got my any closer with a fuel pressure regulator. However... I lined the 0 mark up in the timing window and the rotor cap was pointed at #6. The correct order is 153624, right? Now do I need to turn my distributor 90° because of that?
Posted By: Hotrod Lincoln Re: 235 Plugs and distributor (very long) - Fri Jan 10 2020 02:03 AM
The timing marks line up twice- - - - -once with #1 on the compression stroke, and again when #6 is there. You can set the timing either way. It takes TWO turns of the crankshaft to make the distributor turn once. Turn 1- - - -Intake/Compression stroke- - - - -turn #2- - - -Power/Exhaust stroke- - - - -"Rinse and Repeat!" The firing order is 1-5-3-6-2-4. If you turn the distributor housing 90 degrees, NONE of the cylinders will fire correctly.

Good luck, guys- - - - -I'm over and out!
Posted By: Dragsix Re: 235 Plugs and distributor (very long) - Fri Jan 10 2020 02:03 AM
Take no. 1 plug out and put your finger over the hole. Using a remote starter button crank the motor until you feel compression. Then rotate the motor by hand until the bb on the flywheel is at the pointer. I usually take all the plugs out and use the fan and belt to turn the motor. Once the bb lines up with the pointer, You are now at Tdc for cylinder no. 1. Trace the no 1 plug wire to the cap and put a vertical chalk mark right under the no.1 tower. Look at the octane selector plate and put it at 0 degrees. Take the cap off and look at your rotor. It should be pointing at your chalk mark. If it’s not, loosen the screw on the clamp, not the hold down bolt, and turn the distributor until the rotor is pointed at the chalk mark. Tighten the screw. Install your plugs and wires. Confirm the wires are in the correct firing order. You are now timed to fire at tdc.
Posted By: jstoob Re: 235 Plugs and distributor (very long) - Fri Jan 10 2020 03:05 AM
Everything is timed right. This is maddening. The spark plugs I put in yesterday are already black and sooty from all the test fires. I'll try throwing the original carb back on, and checking the exhaust for obstruction. I'm just running out of things that could be bad. It just does not want to start.
Posted By: Tommy Re: 235 Plugs and distributor (very long) - Fri Jan 10 2020 11:28 AM
You seemed to have changed everything that would make a difference. However, You said the truck sat for years outside, I would wonder if the exhaust my have been the home for some rodents. Take the muffler off and see if it makes a difference, Rats laove making homes in exhaust pipes and mufflers.
Posted By: glenns towing Re: 235 Plugs and distributor (very long) - Fri Jan 10 2020 03:39 PM
Not enough spark? I see a resistor wired in. 12 or 6 v coil being used? Use a 12v for sure and eliminate the resistor. See what happens. I dont use a resistor and my 261 runs fine. Food for thought.....
Posted By: 1Ton_tommy Re: 235 Plugs and distributor (very long) - Wed Jan 15 2020 04:31 PM
From the picture it looks like it has an electric fuel pump. I don't see a mechanical pump and the fuel line follows the heater hoses. What is the fuel pressure? There are only a few electric pumps sold now that produce carburetor level pressure. You have to look carefully at the catalog entries to find one that puts out low pressure. With either carburetor you may have to either replace the pump with one that puts our low pressure or buy a pressure regulator. I know that eight pounds will flood a pair of 228 Zeniths -- four pounds at all is fine. New reproduction mechanical pumps of any brand are a crapshoot.
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