1991 Civic 1.5L Stalls During Warm-Up

[lanceair]

Hello all. I am working on a Civic Hatchback w/1.5L PGM-FI system. The vehicle came to me with idling problems and a code on the computer. Code was for EACV malfunction. I tested the air valve and it was indeed shorted out and non-functional. Replaced it with a new one. Made a nice improvement in idle characteristics. However, when the engine is started cold and allowed to come down from high idle to warm idle condition, it will stall. It will start right back up without hesitation but the idle will continue to drop off until it stalls again. I can let it sit for just a few minutes while still warm, restart the engine, and it idles perfectly smooth thereafter.

I have performed multiple "cold starts" and the problem is consistent every time. As the engine comes off of cold (high idle) condition, and AECV valve begins to close, and tries to settle into warm idle, it stalls.

Any ideas?

 

[White90EF]

maybe a fuel thing possibaly ?

 

[hondablackout]

I'd say check all your fuses first. Then if it isn't electrical try taking a look at your fuel system. You might just have a faulty fuel pump. It could be that simple. Good luck.

-BLACKOUT-
"Civic Dressed In All Black"

 

[lanceair]

Already checked fuel pressure. It runs steady at around 34 lbs. Fuses are good. Car runs great except for this one glitch during warm-up cycle.

 

[Civvy4Life]

Check the main relay its located on the drivers side under the fuse panel to the very left
It's tough to get at but it could be the cause because its the first part of the fuel cycle