I have a 1994 Honda Civic Hatchback EG4... D15 engine. During start up everything is just fine... as soon as I put it into reverse the idle drops... probably 500 or just a hair below. Kinda makes the car shake a bit. And as soon as I get going it's just fine... until I come to a stop, then it goes back to the low RPM and does the whole weird vibrating thing again. It seems to do this noticeably more during hot humid weather. I don't think it's the alternator, the light has never come on for the battery. I've read up a bit on this and I'm pretty sure it's the O2 sensor, or some IAVsomething near the throttle body(sorry I don't work on car engines... I work on F16 GE 129 Turbofan Engines lol). Any ideas or thoughts on what I should do would help and be greatly appreciated!!! I'm stationed in Misawa AB, Japan... so the car is straight up Japanese if that would make a difference. Thanks for your time!

A1C Johnson

 

clean the ivac sensor and also probaly adjust timing.

https://www.hondacivicforum.com/foru...ad.php?t=62836

thats the diy clean the ivac

 

Is the CEL ON?

Check whether the PCV valve is stuck closed, and definitely clean the IACV/EACV on the throttle body:

 

Thanks a bunch, I'll definitely do that once I'm off duty today!!! And no the CEL isn't on.

 

Just try to think of your Civic engine as a small jet engine -- at least this might make repairs seem more interesting.

 

Yeah, before joining the Air Force, I had never really thought much about car engines. But luckily the same mechanical principles that we use on F16's apply to every day car engines(especially removal and install of parts). I've been doing A LOT of reading lately on car systems, and picking up on it pretty quickly. Hopefully when I get to be a normal person again, I can be an auto technician. Being a fighter squadron crew chief should help out quite a bit lol!

 

I just took out the IACV, and the screen looked pretty clogged so sprayed it with some carb cleaner, gonna let it set out overnight(sunlight is gone at the moment), so gonna install it tomorrow. Hopefully this is it

 

Sounds promising. How did the PCV valve check out? If air can't flow properly through the PCV system, you can also get a low idle.

 

Yep, it was a faint noise, but nonetheless made it.