Have trouble starting when hot.

[adecanmin]

Gentlemen
I have a 93 with 361,000 miles. It will start when cold. If you turn it off it for say 30 seconds, it'll start right up. If you wait 10 minutes or so it takes sometime several cranks to barely get it going. If it starts it'll idle about 200rpm. I'll use the throttle to eventually get it running. Even with the throttle it almost stalls. Once it gets going it runs fine. No stumbling, accelerates fine.

Here is what I've troubleshot so far. I checked for spark. Got it. I checked fuel pressure with a gauge and it is within specs. The reading stays steady. If something was leaking the gauge did not show that. I replaced the ect sensor. Thought maybe it was sending incorrect engine temp information to ecu. I think it is getting too much fuel at startup. I changed the main relay no difference. When I had one no start I took the spark plugs out and they soaked with gas. I cleaned off the gas reinstalled them. The car started hesitantly. I have a spare ecu I wonder if I should try that.

[Raf99]

Jeesh, this sounds like a jumped timing belt tooth almost. But if it runs fine once going and engine isn't shaking etc. then it's not that. I'm a bit stumped on this one. It almost sounds like it's not getting air, very very clogged air filter too. Or a dirty fuel tank sock......
But it's none of these as when it's cold it starts fine. Maybe a igniter in the distributor....

I'm going to say it's the fuel pump going out, hence the several cranks. Did you test the fuel pressure when it was hot?

Any check engine lights?

[adecanmin]

Thanks for responding. No CELs. I checked it when hot. Pressure 38 psi. When I disconnected the vacuum line going to the fuel pressure regulator, the pressure went up to 45 psi. Maybe it's one of those problems that defies all logic. I'll try the another ecu and see what happens. I would hope it's not the fuel pump. Like I said before, when I get it running the engine is flawless. Maybe I'll just leave it running and not turn it off. LOL. I thought about a weak spark issue. Maybe I'll get a distributor at the junk yard.

[Grumpys93]

If the plugs are soaked, and fuel pressure at the rail is within normal range, which 30-45 is normal, then your having an issue with your spark. I'm willing to bet your igniter, is going out. Have you looked at the rotor cap inside the dizzy or the dizzy cap? Those contacts could be ground down, just over normal use.

[adecanmin]

I did check that there was spark using a spare set. I dangled the spark plug wires the valve cover and attached the spark plugs to each wire and watched them in the dark. It doesn't tell me how strong the spark is. I just tried to start it a few minutes ago. The engine was warm It started but it was only running at about 100 rpms then died. I took the cap off the rotor checked the igniter wires. I have an igniter I can try.

[Raf99]

You should try unplugging your IACV for fun.

[adecanmin]

You should try unplugging your IACV for fun.

I found the issue. My head gasket is leaking. So There is water and coolant going into the cylinders and on the spark plugs.

[Raf99]

Well....... dam. Best of luck there. Guessing you have low coolant all the time too.

[93shitbox]

In my experience if a car starts fine cold then has trouble once warmed up then the injectors may be leaking. The engine needs more fuel on a cold startup so no issue when cold. I usually have better luck flooring it when I start it up warm. I’ve been told that in most vehicles (not sure about obd1) that flooring it while cranking puts the car in a flood clearing mode that will cut fuel.

[Eggman]

Main Relay. It's a very common problem with Hondas. There's a solder point that goes bad and is triggered by hot weather. This prevents it from turning on the fuel pump. Turn your key on and if you don't hear the click of the relay and pump, then that's it! Simple fix.

http://www.diymyhonda.com/civic/hard...-relay-repair/