Starts Cold & Hot, but no so much "warm"

[Redsquall]

It starts right up when cold.
I let it run for 10 mins and turned off, then starting it back up right away and it starts up quickly.
Let it run another 10 minutes, turned off, then started up again fine
Let run 10 minutes again (30 mins at this point) and fans kicking on normally. Started up again fine.
Turned off.
Tried to start about 25 mins later, wont start, try again, again, push pedal down, starts up chuggingly (but starts) and run chunky, wanting to die.

What does that sound like?
Thanks

[Redsquall]

Just tried to start it, it was very hard to start (smells like getting too much fuel) and then I realized I still had the bottom left spark plug wire off because i looked in it 10 minutes before that (noticing it was a little wet inside and got rusty - the one above it looks nice and clean) so i plugged it back in and it started, but still a little rough and smelling rich. (could having one spark plug wire off really make it act like that?) so i am wondering if this means nothing because i botched the test with the spark plug wire off for a little bit - maybe putting too much fuel in, or if it's still too rough. I do think I smell gas on the dipstick but not sure how it should smell normally - maybe i should smell my other car's dipstick as comparison?




It starts right up when cold.
I let it run for 10 mins and turned off, then starting it back up right away and it starts up quickly.
Let it run another 10 minutes, turned off, then started up again fine
Let run 10 minutes again (30 mins at this point) and fans kicking on normally. Started up again fine.
Turned off.
Tried to start about 25 mins later, wont start, try again, again, push pedal down, starts up chuggingly (but starts) and run chunky, wanting to die.

What does that sound like?
Thanks

[Bitsyncmaster]

Verify all the plug wells are dry and run your test again.

Most common hot or warm start problems are loss of rest pressure. You can check for rest pressure by removing the air cleaner and lightly touching that round air plate to see if it moves. You don't want to press it hard with rest pressure because that will force fuel from the injectors. When you have no rest pressure, a light tap and that plate will almost bounce because it moves so easily.

[Redsquall]

OK, I will take off the filter housing and do another test today. For how long should it have fuel pressure and not bounce? Is one hour at the right amount? Thank you sir


Verify all the plug wells are dry and run your test again.

Most common hot or warm start problems are loss of rest pressure. You can check for rest pressure by removing the air cleaner and lightly touching that round air plate to see if it moves. You don't want to press it hard with rest pressure because that will force fuel from the injectors. When you have no rest pressure, a light tap and that plate will almost bounce because it moves so easily.

[Jonathan]

I'd throw those test results out the window and test it again. If the disconnected spark plug wire did one thing for sure, it would have been flooding that cylinder with unused fuel.

If I went with what your initial post mentioned, I'd say an accumulator failing is the culprit. Yes, it would probably be better referred to as a WARM start problem rather than a HOT start one. My own car had issues right around the 30 minute mark before I changed the accumulator. Sure, the engine was still hot in the sense that you'd still burn your hand if you got placing it on different spots, but thinking of it as "warm" seemed to better describe how it was off for half an hour already.

[David T]

Next time it won't start either try the plug swap or see if you have spark. That will narrow down the system that is failing. Could be the accumulator but it could also be a bad impulse coil or a bad connection in the ignition primary circuit.

[Bitsyncmaster]

OK, I will take off the filter housing and do another test today. For how long should it have fuel pressure and not bounce? Is one hour at the right amount? Thank you sir

If it holds longer than your problem shows up that would tell you rest pressure is not your problem. I have found holding rest pressure for 3 hours is not enough in the summer 100 deg days on my car but 4 hours is enough.

[Redsquall]

OK - does this matter: it was running seemingly fine for 30 minutes. Does that aluminate the bad impulse coil or a bad connection to the primary ignition circuit? Or can those two things acted up once things are warm? (trying to eliminate possibilities) thank you very much


Next time it won't start either try the plug swap or see if you have spark. That will narrow down the system that is failing. Could be the accumulator but it could also be a bad impulse coil or a bad connection in the ignition primary circuit.

[sdg3205]

You really need to throw some CIS gauges on and see what is happening or you'll be guessing for a long time.

You can test your accumulator with a vacuum. IIRC, if the diaphragm has a leak, you'll draw fuel and loose vacuum.

This video (https://youtu.be/5UtYeqmt8OI) is a hot start issue as a result of a bad fuel pump check valve. I also included pictures of a PPR O-ring that caused a hot start issues.

[David T]

OK - does this matter: it was running seemingly fine for 30 minutes. Does that aluminate the bad impulse coil or a bad connection to the primary ignition circuit? Or can those two things acted up once things are warm? (trying to eliminate possibilities) thank you very much

No, it doesn't. The only sure way to know is to see what is wrong when it won't start. It's going to be either fuel or ignition. Otherwise you are dealing with an intermittent condition that you can't replicate. About the only thing you can figure since it ran for over 20 minutes is the impulse coil is probably OK.

[Redsquall]

Thank you guys– I will dive into this further