The Stovebolt Site Forums The Shop Area Engine Shop 57 235 Dies on Acceleration - Final Update/Results

Don - the resistor heats up and the open circuit shows up, a short would show a lot of smoke and sparks .... usually once a resistor goes it's gone, and it shows up by the engine starting fine, when the resistor is bypassed, and quitting as soon as you let off the starter and coil power needs to come from the resistor

and daddy, bypassing the resistor for a test run will not destroy the points - at worst running a piece of emery a few passes between them will fix up any carboning - the resistor is bypassed and the coil gets full voltage every time you start the engine .... don't understand folks claiming points are trouble, I've always had them on these old rigs and get lots of dependable life out of them, sometimes without even touch ups for long periods

Bill

From previous experience... 25 freeway miles each way and the points were too pitted to be filed down... after 50 miles. Your experience with points isn't uncommon. I drove 60k miles in 3 years with my first 59 gmc 6 and a points ignition. I understand how to set and gap them. In recent years imported points, condensors, caps, rotors, coils, plugs and wires have flooded the markets. The last set of points I installed a few years ago lasted only 2 weeks and 300 miles . After looking at the fried points and seeing the country of origin stamped on it, it was no big surprise. Chinesium does not have the same metalurgy as original equipment.

Under starting when the resistor is bypassed, the voltage going to the coil is reduced by the huge draw of the starter. True it won't hurt the points to bypass the resistor for a few seconds. It will absolutely destroy the points to drive with the resistor bypassed for any significant amount of time. I suggest to try bypassing [your] resistor for 50 miles before you give the advise that it will not hurt the points. I guarantee you will come up to the same conclusion. I'm not trying to start an argument here. I'm just passing on my experience when I did what was suggested. I made that mistake... once!

Understood, Gentlemen. And thank you.

Chatting with a much smarter friend (than me) yesterday, we both wondered aloud if the P.O.'s solution of running an internally resisted coil was a better idea. Bill, is there a reason these TF trucks run the resistor? Please forgive my ignorance.

Also, are the original style foot starter-type ignition switches still available? I see a of of key start ones...

Next tests start this weekend. Or maybe today if the weather keeps me from going to work. A truly mixed blessing.

Will post results soon after.


Jim

Jim, the ballast resistor [actual name] started with the change to 12V and continued to sometime in the 60's when the switch to an internally resisted coil happened - the purpose of it is to limit the current thru the coil to prevent it overheating - as said somewhere above, the ignition circuit is setup so the resistor is bypassed while cranking in order to insure a strong spark when the starter is drawing a lot .... the primary purpose of the resistor in the circuit when running is to prevent overheating of the coil and it's eventual breakdown .... so you can eliminate the resistor by using a later style internally resisted coil, but the resistors work fine and are dependable - most coils will be labeled as needing an external resistor or not needing one, do not use both

thinking of that reminds me that the purpose of the condenser [capacitor] is to limit the amount of arcing at the breaker points when they open to 'break' the primary circuit in the coil, which induces the high voltage secondary circuit to send a jolt to the spark plug .... any time you replace the points, replace the condenser as well

and by "original style foot starter-type ignition switch" you mean the mechanical contact box on the starter? AFAIK they're not available anywhere, but they can sometimes be repaired

Bill

Bill, to my knowledge Chev never used a internal resistor coil. When they dropped the external ballast resistor they went to a resistor style wire running from the ignition switch to the coil instead.

As far as running without a resistor for a short test, this should cause no problem.
As some of you know I run a repair shop that specializes in Pre 68 Chevs. I have had numerous cars and trucks come through my shop that had been converted to 12 volts where a dropping resistor was not installed. These were running fine with no points problems. The main thing I see with this is the coil, which has a flat bottom normally, will be bulged out from the extra heat caused by the higher voltage.
I was only recommend hot wiring for a short test only.

I have one other idea. Could you give the number stamped in the beaker plate in the distributor?

Dave, I will do that when I get home tonight.

Bill, thanks again. But what I meant by that ignition type is the "two-position" type switch that only has "off" and "run" (these are not written anywhere, just how it works. No spring-loaded "cranking" position. I see the key-start ones in the magazines (like Classic Chevy), but I am thinking these are the three-position type. But don't know. Their stuff never really goes into detail.

Jim

the V8 key start ignition switches are the only ones available, the 6 cyl switch hasn't been reproduced

Bill

Great...so if that ends up being my problem, I have issues.

Oh well, good time to learn how to service one of these, I guess. An opportunity to learn!

Thanks.

Jim

hey fourb, mine use to run so well it would still run when you pulled out the key..lol

best tip here, take it to a mechanic , get an estimate
then fix it your self..........

I have no reservations why I changed professions......and when it doesn't work go see the poor guy about the estimate you wanted for free.....

I never had a free estimate
at least you know it will be fixed right

'Dave,

The plate that the points are attached to bears the number '1112403' with serial '1K24' as shown here:

http://i1195.photobucket.com/albums/aa397/fourbrads/DSC04224_zps37f2c488.jpg

Does that help? I think this dizzy is original to the truck, but don't really know. A new one is on my quest list for the junkyard tour in February.

Jim

That is the correct distributor.
I thought someone may have put a 216 distributor in it.

Thanks for the suggestions, Stocker and Joker,

The last time I took my truck to my mechanic, he had it for 6 weeks just to change the clutch. Of course, issues came up, like my flywheel was dangerously cracked. I ended up schlepping parts from all over the state to get him up and running. Ended up feeling like I had done the work myself.

Because my truck is not a daily driver, and everyone else's in this shop was, he had mine off on the last lift and had his guys work on it as he could. He runs a really good shop and I trust him. He does great work on all of my newer vehicles. I think I just reached the limitations of how his shop is tooled and what it takes for him to make money. No ill will there.

That said, and with suggestions above in mind, I will work on it myself from now on...

Back in the day when experiencing a problem such as you describe, first thing we would do is make sure the engine was getting fuel. If all was ok there it was time to replace the condenser. They can at times intermitently cut out and the engine does just as you describe. It's not too uncommon to get a bad condenser from your local FLAPS.

Thanks Martin,

I did change the condenser just before bypassing the resistor, so maybe that was the issue and not the resistor. I think Red58 and SWEET also suspected the condenser. I suppose I should have tried one thing at a time, but you know how you get on a roll?

I'll hook everything back up again and see how it goes.

Appreciate the help.

Jim

could even be a small crack in the dizzy,
just for fun you might start it at night and
see if you can see any sparking jumping from anywhere.. sometimes you might get lucky and see a plug wire leaking, etc

I just ran it for about 20 minutes. No stalls, even at higher rpm. I do have some carb issues to work out (it likes to run with partial choke and not without, so my timing may be off for that).

No fireworks seen.

I am still going to see about a new-to-me dizzy during the junkyard tour. Can't hurt. Wires are all new and I don't see any arching.

Keep the suggestions coming. Tomorrow, if the snow is melted enough, I'll head out for a longer test run and see what she does. Still getting the popping and burble on letting off the gas rapidly, but this could be so many things I hate to even mention it.

Did I mention that SWEET and I blew up the muffler on one of our runs a few months ago? So, as for exhaust back pressure....I have none.

Jim

is it popping out of the tail pipe, I heard that would probably indicate ignition problem rather the fuel...

snow, what snow

Joker,

I can't tell if it's popping from the tailpipe at all, or just from the taco-shaped appliance that used to be my muffler. Pretty loud from there.

The only reason I bring this up at all is because I will next (after fixing these ignition issues) be installing a new exhaust system and I don't want to buy it twice.

And, not much snow, but enough to make my squirrely steering really challenging. Front end rebuild next, I guess.

Thanks,

Jim

The fact you have to pull the choke out to get a smooth run concerns me. If I recall correctly, it can mean a couple of things. Not enough fuel to the cylinders or a compression leak somewhere. Like I said it has been a long time since I had to use my diagnostic skills so I may be off.

Okay,

After extensive testing, the original symptoms observed seem to be down to a bad condenser, as a few have suspected.

I have the original ballast resistor reconnected properly (as before), the original coil, and a new condenser. Timed as best I could, then ran a few preliminary tests, described in the last few posts.

Had SWEET over yesterday and we really ran her through her paces. Multiple starts, stops, hills (including a 15% grade near my house), high speed and low. Zero stalls.

Right result, I think. I may still have some minor issues going on with my distributor, but I will run as-is for a while and see that she continues to perform well.

My sincere thanks to everyone for their input and aid.

Respectfully,

Jim

Here is a clip of our progress:

Test Run

Well it's certainly rewarding to read through 7 pages of sleuthing then getting to the end and reading the report then going for a ride to boot... How do you mark a thread so it stands out in the search/find pages?

CASO,

Not really sure how else to mark it, but I did change the title because the time had not run out on editing. Glad you stuck with it through seven pages, though!

Jim

it is sure nice to have someone give us a final tally, too often we go through 3,4,5 pages then the person just disappears never to be heard from again leaving all of us hanging. thank you

Sure thing, brokenhead. I suffer the same let-down on some of the longer posts and thought maybe I should start with mine.

I guess I just need closure...sniff...sniff...

Best,

Jim

there, there, it will be fine.

Final, Final note:

One of the things I tried during this process was modifying my fuel pump. I think Bill had recommended this to compensate for a worn cam lobe. Well, dummy me...I announced that my cam lobe looked great, with no signs of wear, yet made the modifications anyway (a blob of welding material on the lever arm to engage the cam better).

So this weekend, while checking my oil level, I noticed it was overfull and smelled of gas. Glad I checked it! Plus, some black soot from the new tailpipe.

Checked the forums and found that this was almost certainly a failed fuel pump dumping gas into the crankcase. I suspect my fiddling overstressed the pump diaphragm because I was probably getting full travel out of the arm. A guess, but seems logical.

Replaced the pump and all seems to be well again. Will monitor this though to make sure the pump is what caused it. I did check the pump that I removed and it seems like there is an extra inlet noise when I depress the lever. No real way to be sure, with my skills.

Just a word to the wise; Don't fix what's not broken or it will be.

Best,

Jim

Jerry- I'm glad you posted this... I don't have too bad acceleration issues with my 55 235 Roch carb, but with repeated (2x) water drop in the bowl, I'm going to drain and clean the gas tank & lines now. Bet that fixes the hiccup.
Thanks
Brad

Look at it this way, fiddling with the fuel pump helped clean out the oil system, so it wasn't all bad. I bet the oil came out thin and dirty.

Glad your back on the road.

Joe