hard to start after sit short time

[ej69]

car is hard to start after left sitting for 10 min or more after a drive. figure it has to due w/ fuel percolation. i have a factory 4bl intake, w/ an aluminum adapter w/ an edelbrock 650 carb, new stock fuel pump. i had the fuel line/filter lying beside the heater bypass hose, and prob was bad. car would start fine cold or immediately after stopping, but not after sitting for a while. i changed hose routing to keep off engine and bypass hose, but still have prob (but not as bad).
i read another thread stating needed thick gasket for carb, instead of thin paper style. would it matter much to use thiker gasket. i figured aluminum carb adapter would dissipate enough heat.
other than this carb runs great.
eric

[J-(Chicago)]

Your fuel pump could have a drainback issue.

[bcracing]

I have the same problem. Have a new fule pump and carb. The other day when I was under the car I could hear fuel dripping in the tank. so think it is a drain back problem, but how do you fix it? is the new fuel pump the problem?

[elcaminodave]

I have the same problem. Mine will also start right up after it has been sitting for a week or so but then immediately die. I then have to pump and pump the accelerator and it will finally restart and stay started.

[Lady72nRob71]

I have a big starting issue after it sits a week. I suspect drainback. If it sits a couple hours, it fires right up, but coughs a bit on initial accelleration.
Anyone know of a simple check valve one could put on the suction line right next to the fuel pump?
I heard of some fuel filters having built in check valves. Anyone know? I bought the correct AC Delco one for my 72 but I doubt the check valve is on it...
My 86 does not have this issue.

[70 cutlass s]

Is it hard to start or hard to turn over. If it is hard to start it could be a bad fuel pump, but if it is hard to turn over. If you run headers they get real hot that heats the starter, and they will just barely turn the motor over. If that is the case you need a heat shield for your starter? If you don't have headers check your timing with a timing light make sure it is right? Also another thing to check is the battery and cables if the battery weak or to small that could be it. If you built your motor up any you might need a bigger battery.

[ej69]

it cranks fine. if it was fuel pump, wouldn't i have probs when starting it for first time? it starts fine when first started and if stop and immediately stop. it is after leaving it for a time 5-30 min, that it is a bear, which made me think fuel. is there any validity to running the thicker stock carb gasket between intake and carb adapter. i figured alum. carb adapter would dissipate heat enough. not sure if fuel line getting to hot or carb.

[Lady72nRob71]

Originally Posted by ej69

it cranks fine.
it is after leaving it for a time 5-30 min, that it is a bear, which made me think fuel.

I have similar problems intermittantly. Immediate restarts are fine. Between 10-30 minutes takes extra cranking. However, after 1-2 hours, it will often start easily (ruling out perculation / drainback).
For this reason, i have been suspecting my original coil mounted on the block is failing when hot. When an engine is stopped, it gets hotter from heat soak before it actually cools. The timeframe my failures occur are in relation to the heatsoak times. I need to replace the coil and see what happens. I heard someone else concluding that their coil was the problem.

[bcracing]

With mine, it turns over great, but once its warmed up If it sits for a little while, I have to give it some gas and crank it for a while, but if it sits just a few minutes, I can hit the key and it fires right up. If it sits over night,i hit the gas once and it fire right up.

[ej69]

i'm going to put on thicker carb gasket, check timing and see if helps. i may try to insulate fuel line
see what happens

[Dan Wirth]

I found that if I pressed the gas pedal just once, when my car is dead cold or sitting for even a short while, it would start immediately - otherwise wanted to crank and crank. I was delighted by this quick fix.

[ej69]

thanks for tip dan. i put on a thicker gasket (factory style) between adapter and intake and seems to have improved some.

[jslabotsky]

Originally Posted by Lady72nRob71

I have similar problems intermittantly. Immediate restarts are fine. Between 10-30 minutes takes extra cranking. However, after 1-2 hours, it will often start easily (ruling out perculation / drainback).
For this reason, i have been suspecting my original coil mounted on the block is failing when hot. When an engine is stopped, it gets hotter from heat soak before it actually cools. The timeframe my failures occur are in relation to the heatsoak times. I need to replace the coil and see what happens. I heard someone else concluding that their coil was the problem.

^ What he said. An old friend's '70 350 would run great until warmed up. Then it would start laying down and get hard to start. Replacing the coil did the trick. I guess whatever was wrong internally only caused a problem when it became heat soaked.

[Redog]

Timing issue

[ej69]

car has an hei distrib (alreardy in when bought car) when restoring car, i put in new coil, module, cap/rotor. what should timing be set at, w/ factory 350 4bbl engine. using hei distrib. also what gap do most run on plugs for hei distrib. i set mine at .040.

[ej69]

red dog, i think you are right. i checked timing and it was at 8 w/ HEI, a friend advised to put it at 16 degrees and start prob seems gone, also car runs so much better and stronger. what is timing for a stock 350 using an HEI supposed to be?

[OLD SKL 69]

I set my plug gap with HEI at .40 also. These motors seem to like initial timing in the 12-16 range. Mine runs the best at 15 so I think you are right on target.

[66ninetyeightls]

Hvae you verified for sure that it is a fuel problem??? Does adding some fuel to the carb when this problem is happening fire the engine??

[svnt442]

Originally Posted by ej69

what is timing for a stock 350 using an HEI supposed to be?

Stock HEI timing is 20° BTDC @ 1100 RPM.

[Destructor]

If my car with an Edlebrock sits for say more than a half hour after running it usually takes a couple cranks, sitting 10 to say 20 minutes, no problem. If it sits a few hours I'll give it a pump and it starts right up. On a cold morning it starts up beautifully, never had a cold start issue just an annoyance when the engine is warm and has been sitting a bit, I've adjusted the choke with no effect.

[bcracing]

Hmmm, maybe its a edelbrock thing then, sounds just like mine, and it also has a edelbrock.

[AZ442]

I had the same problum with hard to start after 30 min, OK when cold and OK after 1 hour. I installed a carb spacer made of the black material to insulate the fuel in the carb from boiling. No more issues.

[ej69]

seems like prob was timing. way easier to start now. i had prob w/ quadrajet and edelbrock. car runs so much stronger. may try 20 degrees and see if improves
thanks