I have a 1989 Honda Civic with dual port fuel injection. The car annually has trouble mantaining idle when it is hot and humid out after the engine warms up. The fault code reads one, for electronics control unit. This has been occuring for the last few years but is getting gradually worse. I took it in before and they supposedly fixed it but it made no difference back in 2005. In Nov of 2007 it died while driving and would not start (no firing) Honda replaced the rotor, distributor cap, and plugs which seemed to fix the problem.

Unfortunately, the problem came back this month and it idles so roughly that it dies when you come to a stop. Revving it up sometimes helps return the idle to 1100 rpm. I replaced the plugs, rotor, and distributor cap and reset the ECU but it still idles really rough and when it does you can smell gas out the exhaust. The fuel filter was replaced about 30,000 miles ago. It has 161,000 miles on it and I would love to keep it going longer but I am challenged to solve this problem.

It appears that the engine misses at idle and it drops from 750 rpm to around 150 and stops after firing very roughly for a few seconds.

 

Does it not want to start after it stalls?

My first thought was that it may be the ECT sensor. I suppose it could be failing without throwing a code, and messing with your fuel mix.
Maybe it's causing you to run rich, hence the bad idle and gas smell?
Just a cheap thought...

 

It will start but not as easily as it does when it is cold or not having this problem. When it starts it will run rough till I punch up the rpm by giving it gas.

 

Try replacing the FI 'main relay' with one from a pick-n-pull, just
to see if it helps. Those can cause problems, and are easy to replace
but expensive from the dealer.

Try cleaning the EACV (controls the idle).
Test the intake air temperature sensor.
Test the TPS.

 

EAGERKC:

Did you ever fix your stalling problem?

What was the culprit?

My car is stalling too (same year 89) when engine is hot.

I've done tons of research on the web, it seems to be a popular problem, but, no one has posted a solution.

Please let us know - thanks!

Teamer

 

x2 wanting to know the culprit. I had an issue with a map sensor before. but it's been so long I can't really remember. good luck with the fix

 

Any updates on this issue?

Yes, i am hunting for the possilbilities...

 

ok guys here was my solution to the EXACT same problem.

I had a 90 crx dx automatic.
had a wandering idle, would rev from 700 to 2200 up and down all day long but drove fine.
Also would stall at idle if i turned on the blower fan or headlights.


FIX:
Cleaned the IAC...didnt help, replaced the IAC with a known good unit... didnt help
Pulled off the throttle body and cleaned it with brake cleaner and blew out all the vacuum hoses. Found a dry rotten vacuum hose and replaced that and it Solved the wandering idle.

Next I replaced the whole under hood fuse panel (which contains the ELD unit) with a known working unit and DONE! everything worked perfect again

 

ELD?

 

electrical load detector, keeps the car from stalling when extra electrical load is added, like turning on the head lights, radio, blower fan etc...