HELP! Idle Surging (1500-2750RPM)

[LEATHL EG]

HELP! Idle Surging ('93 EG) 3:01 PM 7/21/2002


Where should I start...
This has been the all time worst and definately most costly problem I have faced in the six years I have owned this car.

The idle is constantly surging between 1500 and 2500. I start the car and it may take five or maybe 15 seconds for it to start, but it has been doing this since before I put her up last winter.

Here is the background on the car:

It's a '93 Civic Coupe DX with a swapped D16Z6. Last year when I was stuck in traffic, I noticed that it was over heating and it managed to get to the point of boiling over and off the top of the temp guage by the time I could reach a spot on the highway to pull over. The radiator was toasted and the fan for what ever reason was not kicking on when the temp would get high.

After this happened I decided to put in a GSR radiator and a FAL fan to avoid any further cooling issues. The day that I did this my car began it's trip down idle surging lane. I initially thought that it was air in the cooling system and I bled it like ten times and couldn't get all of the air out. So, I took it in to the dealership and had them do a professional coolant flush. They told me that they couldn't pressurize the cooling system and that I had a blown head gasket. Great!

Since then I had the head checked and it wasn't cracked so I had a valve job and the head milled. I replaced all of the gaskets with a head set. This was not the problem. I have checked cam timing, it is absolutely perfect, and there is no chance of air getting into the cooling system from the head.

This is what I have replaced or bought since then:

ProFlo Throttle body (59mm)
TPS
MAP Sensor
O2 Sensor
Distributor, Cap, and Rotor
MSD SCI Ignition, Plug Wires, Coil
Timing belt
Alternator, and belt
Battery
Colored Hose kit (hoping to eliminate a vacum leak)

The error codes we keep getting when we short the ECU are seven and three. Someone told me that those are the TPS and MAP. Which I have already replaced. Is this right? I don't have a place to check error code numbers. One time we got a fourteen, but that was after we switched around the wiring harnesses for the TPS and MAP.

I have taken it to like five different mechanics and no one tell me anything. They all wind up blaming it on this extra wiring harness that is hanging off of the firewall next to the TPS. It is just and extra harness that was left over from the 1.5 that was in there before the swap. Just to clarify the swap ran fine for two years before this all went down.

I have no idea what else to do and I have already spent like $900 dollars in the last two weeks alone. If some one could give me any help I would seriously be in debt to them for the rest of my life.

Thanks,

Kyle

[mwelch75]

i am having the same problem with my 93 ex coupe i keep seeing the iacv popping up so iam going to try it maybe u should do the same

[92CivicFoDo]

did you take off the IACV and clean it out? have you tried unplugging it to see if the idle drops down? either way, there is a wrong wire hooked up there or its just clogged

[mwelch75]

Originally Posted by mwelch75

i am having the same problem with my 93 ex coupe i keep seeing the iacv popping up so iam going to try it maybe u should do the same

took the iacv off sprayed conact cleaner in it until brown shit stop comming out reinstalled good to go