93 del sol s. d15b7. replaced the motor and trans with a 92 d15b7. everything works great, motor doesn't leak or burn any oil. The one thing that isn't making any sense...fluctuating idle until it warms up. once it warms up, car idles great and the gas isn't so gosh darn touchy. one thing that keeps coming up when i check codes...IACV. Before you start saying to change or clean it, already have done it. even replaced the FITV, intake manifold, throttle body, ECT sensor, some hoses. I put my finger over the hole in the throttle body..high idle stops. once i take the finger off, high idle again. Ive talked to a couple mechanics that work on a lot of imports. they are very familiar with hondas as well. They said that because the engine is a year older, the ecu might not be reading the IACV right or isn't tuned right because of the year. I thought about it, sounds like its plausible, but just wanted to see what everyone has to say. Im putting on my turbo kit in the next month, and want this problem solved before the turbo, or maybe when i get my ecu chipped/tuned, it could be fixed at that time? any suggestions or comments that would help me..would be awesome.

 

It's the same engine, '92 - '93 have a different map sensor setup than '94 - '95 but that's it even at that the ECUs are all interchangeable.

If you keep getting a code for the IACV you've either got some connectors mixed up or a broken wire or bad ECU if the IACV is good.

 

okay, but i never had a problem with my ecu before. my engine ran sound with the same ecu. its now acting like this with new engine. so its gotta be something with the wires. i used the old engine wiring harness, didn't think i could have cut any wires..ive looked over that. i could have sworn that all my connections are correct. does the map sensor plug match any other plugs around the throttle body area? that might be the only thing. but even that..i took pictures. ****..ok..thanks a lot. ill keep checking ****. its a problem that isn't terribly bad, but annoying enough where it bothers the living hell out of me. ha..thanks again

 

Sorry that I had to bring this post back, but I just found my haynes manual sitting in my house...the last place it should be. So about my erratic idle, the manual gives 7 different reasons of why the engine may idle erratically. Please post if you have ever tried these and if they worked.

1) Vacuum leakage (i already checked vacuum hoses, no leaks that I know of)
2) Leaking EGR valve (haven't looked at this yet)...??? Possibility
3) Air filter clogged (cleaned my filter, not it)
4) Fuel pump not delivering sufficient fuel to fuel injector system ( fuel pump never had problems with last engine and I changed out the injectors and fuel rail with intake manifold)
5) Leaking head gasket (have no smoke from exhaust and oil isn't milky at all, but may have to take a look)
6) Timing belt and/or pulleys worn (possibility, haven't changed them yet)
7) Camshaft lobes worn (never checked them, didn't get inside the engine to look at, but wouldn't the idle still fluctuate after it gets warm??)

So these are the 7 in the haynes manual. It doesn't specify that this is when the engine is cold/hot, but just talks about the engine idling erratically. I'm starting to think that I need to get a new engine, but I really don't want to do that. this topic seems to never get solved. Any suggestions would obviously be great. Happy Monday!

 

so i looked at the problem again and there are two connectors that are the exact same. I have switched them before and nothing happened. I tried it again...car idled perfect! BUT.....when I hit the accelerator..the car wanted to die. I have to really futz with it to get it to rev up. The CEL also went off when I switched them. Any suggestions about how to fix my problem with the revving up and not dying out? If I can fix it I will have finally fixed the problem...unless when i hook them up again..it doesn't work. I don't get it how one time it doesn't work..and the next time it does. this would be great if this is the problem. I am so confused but yet happy that I may have figured it out. idk...please help!

 

what are the wire colors going to the two connectors?

 

the one connector that is on the Sensor Assy. Map has colors - white, yellow with green stripe, green with blue stripe.

the other connector that is on the throttle bottle (backside of TB) has colors - green with white stripe, red with blue stripe, yellow with white stripe.

each connector has three wires. I switched the two opposite of what I just wrote and thats when the idle went down, CEL turned off, and when I hit the accelerator..it almost died. confused. I know for a fact that the way they are connected is how it was when i had my last engine because the map sensor by the firewall had the wires before the connector taped to something to keep them from moving. There has got to be an answer to why this happened. im running out of ideas. also, when I put my finger over the IACV port in the TB the idle goes down with the connectors on normal. thats all i got.