The Stovebolt Site Forums The Shop Area Engine Shop still no joy

after rebuilding my 235, getting all new gaskets, having it perfectly timed, getting it to spark a white arc, replacing all electrical components including coil, wiring harness, points and condenser, distributor, spark plugs, rotor bug, distributor cap and repainting the engine, it still doesn't start (or even attempt to) even when i spray ether in the spark plug ports or put gas down the carburetor throat. it is all but a brand new engine, so what am i missing? someone help me before i lose all control and destroy the engine.




Indy

don't try too hard to start it, you could flood the combustion chamber. i dunno if you did all that rebuilding yourself, or if you had someone else do it, but i'd be double checking everything as it's being done.

do a leakdown/compression test, handcranking the shaft.

what's it doing when you try to start it? noises, indications etc.etc. i don't see anything about messing with the starter

Are the valves adjusted too tight? I had a problem with mine because they were too tight, mine would start but didn't run very well.
Do you have any vacuum leaks around intake/exhaust manifolds?

Possibly the distributor is 180 degrees out of phase or the valves are not opening. Most often when a newly rebuilt engine won't start it's one or the other.

i don't think there are any vacuum leaks around the manifolds, but i will look into it and i watched all the valves open and close, i tested the dizzy and it backfires if it is in the other way, so it can't be out 180 degrees.

It can be mighty slow on time though and not start. Won't backfire either.

Pull the distributor cap and the number one spark plug. Put your thumb over the spark plug hole and have someone crank the engine (stay away from the fan) and watch the rotor. When the compression blows your thumb off the spark plug hole make a mental note of where the rotor was pointing. Place the distributor in a position for the rotor to be pointing at the number one spark plug wire.

Or move the plug wires so that number one spark plug wire is where the rotor points for number one then place the others in order.

I don't think I've ever seen white spark on these old trucks with a point style distributor. A pretty blue color spark is what I want. An orange colored spark may not fire the truck up.

Double check the point gap, and make sure the valves have the correct lash if it has solid lifters. If they are hydraulic lifters, you could have them too tight.

Roy beat me to it, lots to check,

Fuel, compression, spark, oxygen, one of the four missing?

How does it crank? real easy, real hard, normal

How is the battery?

Is the coil wired correctly?

Will a plug fire when cranking? have you checked? a timing light will tell you

Walk away for awhile, get a drink and clear your head, then start over:

1- Pull valve cover and distributor.

2- Prime oil pump with drill and be sure oil is at the rocker arms
hydraulic lifters need to be pumped up so rotate engine while priming

3- pull number one plug and verify top dead center on compression stroke
hold your thumb over the hole to build compression while rotating engine

4- verify both valves are closed on #1 cylinder

5- check timing marks and verify TDC marks with piston position

6- verify rest of valves are set correctly
( 1/2 - 3/4 turn down from zero clearance )

7- prime oil pump one last time, and drop in distributer with rotor
pointing at #1 plug wire terminal

8- check for fuel at carb, does it spray when the throttle moves?

9- hot wire coil right off battery to bypass any wire issues

10- crank over and see if it fires, use 12 volt battery if needed to crank
it quickly. The points will survive for a while on 12 volts.

If it fires up, run a normal break-in period, read up if haven't already and be sure to use correct break-in oil.

If it still won't hit, check for proper cam timing, the gears could be miss aligned and no amount of tinkering will make it start. Open valves (miss adjusted) will also keep it from starting, no compression.

Either is not good on new motors, and it doesn't always tell you what is going on with them. I have seen it not fire one lick in a good running engine. Seems some cans work better then others. Just cause it won't fire doesn't mean it doesn't have spark.

Rotating the distributor while cranking is generally need, go both ways to see where it might like it, if it kicks back, go the other way. Keep your face away from the carburetor!!

Get some more information and report back

Joe

1. DO A COMPRESSION CHECK. If you have 80#'s or more on each cylinder then the valves and valve timing are good enough to start and run.
2. Pull coil wire from THE DISTRIBUTOR CAP and hold 1/2" from a good ground. Crank over with switch on or jumper in place and if blue spark the coil, points, and condensor are good. Plug coil wire back into distributor and hold a sparkplug wire a 1/4 to 1/2" from good ground. If good spark the rotor, cap, and wire is good.
3. Pull #1 sparkplug and turn engine till air hisses out past your finger tip and the pointer in the view hole just above the starter is lined up with the BB in the flywheel. Take off distributor cap and note where the rotor is pointing, put cap back on and put the #1 wire in the position the rotor was pointing and then plug in 5-3-6-2-4 in a CLOCWISE direction from the #1 wire.
4. Pour a shot of gas in the carb and fire it up. If it keeps running your home free (may take several primings). If not there is a fuel supply issue.

it cranks normal, forgot to mention that i had the starter rebuilt too; i got the bb and needle thing lined up, rotor bug points at plug wire #1, firing order is 153624 in a clockwise direction, and still nothing: what next?

Pretty blue spark?

Have your resistor in line or internal coil resister? Have a jump wire from starter solenoid "S" post to positive coil post?

my guess... 180 out of time.

i finally got it to try to start, had to work on the static timing and now i gotta get the carb adjusted right for it to run, how many times do i unscrew the air mixture screw and how do i get the float adjusted perfect?

The idle mixture has almost nothing to do with starting it. The beginning point for the screw is 1 1/2 turns open. You need full choke and some throttle to start it.

When it is trying to start you will hear the starter start turning a lot faster. I would try varying the timing a little each way. Too much advance will make it stop dead when trying to start it.

The float level should be set to spec which is something like 1 9/32" if I remember correctly.

also should there be fuel being visibly sprayed into the carb throat when i pump the gas pedal? if so i don't see any

Lots of people drive themselves crazy trying to determine is it Fuel or is it Spark. This is totally a no brainer if you use Starting Fluid. You take the air breather off, spray a few squirts of starting fluid down the carb and try to start it. If there is a pretty good 'run' for a few seconds, its fuel. Now you can diagnose whatever is happening with the fuel lines. If there is absolutely nothing, its spark. Now you can concentrate on the coil, dist, etc. Hope this helps. It sure helped me!

My guess would be the cam isn't timed right.

i didn't take the cam out so i know it's not that, i think it's the carb because it does try to run with carb cleaner or a little ether down the hatch, so i'll be getting a carter YF carb soon to solve my problems


thanks for all your help guys,


Indy

I would not be using ether or carb cleaner. You could end up regretting doing that.

I almost always put the distributor in 180 out... even when i'm sure it's in right...

there is absolutely no reason to use ether, I have never used it in my life, I spent a good portion of said life in Montana, and Alaska, where it can get really, really cold. (The rest of my life has been in tropical paradises) The distributor can be anywhere, all that matters is if the wires are in sync with the rotor, wherever that sits with #1 on TDC compression, that will be #1, and then go clockwise in the correct order. But you need to get the static timing correct, There is a post going around right now about "235 engine won't start" which has a couple of links to some very good (if not somewhat convoluted) instructions on how to set everything up. I don't know if this engine has been running previously, and don't think just using a carter carb will fix everything, I have had the same rochester for 30 years now, the beauty of them is simplicity. Unless something has been broken, taken out and lost or put back in the wrong spot, plugged or something like that it should work just fine. There could be a leaking throttle shaft, or something like that. Or you got one of the little intake rings hung up and are sucking air. Keep us informed.

i believe it is a leaking throttle shaft