Trouble starting when engine is warm

[devanray]

77 C-10, 350 with a 400, unsure of gearing, 1980 Rochester Quad.

The truck starts up fine first thing, but it seems that after the engine gets warm it will just crank and not actually turn over. I have to really give it some gas, to the point of flooding it before the engine catches and then it is all 'boggy' because of the amount of gas I've given it. Here is a real life example:

Started fine, drove for 10 minutes @ 45 mph, shut it off, five minutes later it started with no problem, drove for 35 minutes @  55-60 mph and shut it off for 20 minutes, wouldn't start.

Different day; Started fine, drove for 5 minutes @ 35 mph and shut it off for 10 minutes, started up, drove it 1 mile @ 10 mph (crossed the street) and shut it off for 5 minutes, wouldn't start.

Any ideas? I don't even know where to start, seems somewhat random.

Thanks in advance

[devanray]

Today she had trouble starting first thing. When she did start white smoke blew out from the exhaust. I have also noticed the other day the level in the fuel filter had dropped, it still started fine then, but shouldn't that level be the same always?

[87454westernhauler]

do you have any pictures of the filter when it is running, it may be getting low fuel pressure when it is hot cause of a bad pump or maybe a restriction maybe?

[devanray]

I'll see if I can get a shot of it after running for a bit (tomorrow). I was thinking fuel pump might be an issue as well, any good way to test?

[Lt.Del]

I had the same problem with my 79 a few years back that when I drove it, then turned it off for a minute or two, it wouldn't turn back on unless it sat for 20 minutes or so.  It always turned on just fine when the engine was cold.  It was the module in the distributor that went bad.
You can also check to see if your choke opens all the way after two minutes of driving.  When you restart a warm engine, the choke should be open all the way.

[devanray]

I had the same problem with my 79 a few years back that when I drove it, then turned it off for a minute or two, it wouldn't turn back on unless it sat for 20 minutes or so.  It always turned on just fine when the engine was cold.  It was the module in the distributor that went bad.
You can also check to see if your choke opens all the way after two minutes of driving.  When you restart a warm engine, the choke should be open all the way.

Was it an HEI? I only noticed this issue after I took the cap off to plug in the tach. I really didn't think it would be the cause but more just a coincident. How did you figure out that it was the distributor module?
I'll check the choke as well (tomorrow when the rain and winds die off), its an electric and wasn't hooked up when I bought this rig, maybe thats why. Umm... whats the best way to check it, on the four barrel, does it open the primarys when "the choke is open all the way"?

[TexasRed]

I had the same problem with my 79 a few years back that when I drove it, then turned it off for a minute or two, it wouldn't turn back on unless it sat for 20 minutes or so.  It always turned on just fine when the engine was cold.  It was the module in the distributor that went bad.
You can also check to see if your choke opens all the way after two minutes of driving.  When you restart a warm engine, the choke should be open all the way.

Did you finally check the module? I thought you said you were pretty sure it was the pickup coil.  . .
http://forum.73-87chevytrucks.com/smforum/index.php?topic=9335.0

You have to pull the module out of the distributor to have it checked at the parts store. Although, if your choke isn't hooked up to B+ but you still have everything there, that can cause some problems.

[Lt.Del]

Texas, you are correct, it probably was the pick up coil, sorry.  It's been a few years and at my age, memory becomes fogged.  It's easier for me to just replace the whole distributor since I have so many and they are cheap at salvage yards.

Yes it is an HEI.

Checking the choke is easy.  The top flaps are either open or closed after you activate the accelerator.  They should be open when the engine warms for a few minutes.  They should be closed when engine is cold and hasn't been run for a while.  I guess there is an in between (half open, half closed) if the engine is a little warm perhaps--but i like to simplify the concepts so its easy to understand.     

[jameswoodlee]

could it be the starter is getting to hot??

[devanray]

Don't think it is the starter, she cranks up just fine. I'm thinking that it has something to do with ignition or fuel. I'm not used to HEI so I don't have a clue how to test the coil either, can an autoparts place test the module and the coil?

[txchainsawgogi]

could it be the starter is getting to hot??

Could be if its caked in mud

[devanray]

The starter is clean, if it were to hot than it wouldn't crank, right?

[Lt.Del]

Next time you have the problem of it not starting, check for spark at the spark plug.  A bad pickup coil will make it so you have no fire (spark) at your spark plugs.  

I'm not used to HEI so I don't have a clue how to test the coil either

Remember, you have two coils in the HEI distributor, the actual "coil", which has 4 little screws.





and the pick up coil which is further down the distributor, a ring shaped gizmo with a wire...what you describe sounds like a problematic pick up coil to me, if you don't have spark when engine is hot...



http://www.youtube.com/watch?v=z47TliL4OJ4 testing spark for pickup coil.

could it be the starter is getting to hot??

If that were the case, the starter wouldn't even turn.  It doesn't sound like that is the problem.

[devanray]

I suppose now is as good of a time as any to get to know an HEI. I'll take it apart tomorrow, this can be done pretty quickly with the dist still in the vehicle right?  Doesn't look to tough to take the HEI coil out but how much farther down is the pickup coil? This should be fun.

[choptop]

need to figure if your fighting fuel or fire. I keep a good spark pkug handy when trouble shooting things like this. Whe it refuses to start, pull a plug wire off, put the plug in it and lay it so it will ground out against engine block. Crank it over and listen for tick ( spark sound can some times be heard) or it is better if you have someone crank it for you while you look for spark. I wouldnt hold the plug while cranking because its gonna hurt. Some people do know that, im not meaning to indicate you dont. Just in case tho. If you have spark, then its possible a fuel problem. I had ha 68 Elky that had some similar issues after a header install. My inline fuel filter, similar to the one you showed but mine was metal, was getting hot causing the fuel to vaporize once it got to the carb. I relocated the filter further away from the headers and all was good. Also had a motor home with a 454 doing a similar problem and an older mechanic wrapped the fuel pump in tin foil as a heat sheild. Problem solved.Just some thoughts.