Alright. I no longer have any idea what's going on with this car. So, if you know what might be happening here, I'm all ears:

I've got a great little 1991 Civic DX, 1.5L manual. It's never let me down and I love working on it.

Stalled on the highway a couple weeks ago and I couldn't get it re-started. Over the years, it's had a bit of a personality where it chugs and occasionally stalls at a low idle, or when very slowly accelerating from a stop. If I'm sitting still, I'd turn the key to full off, give it about 30 seconds, and it'll start right back up. For whatever reason just re-starting without turning off never seemed to work.

So since it stalled on the highway and I wasn't able to get it started at all, here's the list I've replaced or completed:
- main relay
- fuel filter
- plug wires
- spark plugs (the old ones were due, but not overdue, and all four were pretty fouled with burned oil and had oil in the wells)
- spark plug well o-rings and valve cover gaskets
- and fully charged the battery

At this point, if I let it sit until it's cool, it'll start right back up with no trouble. Then once it warms, it starts to run a bit rough, eventually chugs, stalls, and then I can't get it started again - spins a few times, then kinda sticks, then spins a few times, and kinda sticks again.

Any ideas??

 

possible answer:

Honda Repair: 97 CRV trouble starting when warm, honda crv, coolant temperature

 

i had the same issue with y 90 hatch. every time it stalled or i shut it off, i had to wait 30-60 minutes before i could start it again. i simply replaced every inch of vacuum line in the entire engine bay and have never had the issues since.

 

^+1 I was going to say vacuum leak or timing / fuel at operating temperature. We all know these motors Rev up to warm up then idle down once warm. Use whatever vacuum leak check method you would like.

Brake booster was bad on a solar I worked on once. Chased it down for hours..smh. high and low idle problems.

 

Does unplugging the O2 sensor eliminate the problem?

 

Nope, but fixing it does. Get you some carb cleaner and spray all the vacuum
lines and parts that meet the intake manifold. TB,IACV,FITM, things like that. If it revs up or down when you spray it. Whatever you are spraying at the time is probably the issue.

I would fix any check engine lights before you do anything.

 

It's a diagnostic test.