DC2BUD

I have a 96 Integra GSR, when my car is warm the idle bounces up and down from 500 to 900 rpms it stops when i turn on the a/c but it starts again when the a/c compressor turns off by itself. No CEL. Ive checked for vacuum leaks, cleaned IACV then changed it all together, checked all grounds, checked tps with a muiltimeter and changed it, bleed the coolant a million times, checked ignition timing, I even tried another chipped ecu with the same chip but nothing. Im stumped and its so freaking annoying.

Ovrbst_T66

Check the fast idle valve under throtlle body.Also try this ,there are two holes on the inside of tb plug up one of those holes with your finger and see if the idle stabilizes if it does there is a leak at the tb gasket or the fast idle valve under throttle body.hope this helps u out.

fcm

Could be the ECU/ECM, it will "throttle up" when A/C is on to compensate for the extra load, it sounds like it is working properly when A/C is on, [or engine would bog] but not when A/C is off/cycling.

Have you checked for codes? 94

DC2BUD

I have a omni power throttle body and it doesn't have a fast idle valve. The throttle body gasket and intake manifold gasket have been changed and no change. And the iacv has been changed. It's not throwing any codes on the ecu. I seems like its a bad ground somewhere but I ran a wire to the head,intake mani,block,tranny,thermostat housing while it bounced and nothing. I gave it a tiny little throttle to see if it fixes it like turning on the A/C and it doesn't work.

EMTIV09

Check the screw at the top of the tb sometimes they work loose and especially being your on a aftermarket tb and the screw isn't epoxied In place. If that fails to work. Try carb cleaner or starting fluid at every little joint and spot that they is a gasket. Even the bottom base of the injectors the o riing seals can get old a crack allowing just the smallest amount of air.

DC2BUD

There is no screw on top of the tb just one underneath for adjusting the base idle. I've tried setting the base idle at 600 and 1000 rpms still bounces. I've sprayed carb cleaner everywhere no change in idle. This is the second motor that's been built for the car, the first did the same thing just not all the time. The injectors and seals were all replaced when the new motor was built so was the throttle body,intake mani,block,pistons,rods,cams and all gaskets. I've tried a different dizzy, IAT sensor, map sensor, iacv, tps, ecu. I'm all out of ideas! O2 sensor or plug wires maybe just no cel...? Thanks yall for the replies.

fcm

Is it the same ECU/ECM?

Giving it a little throttle is not the same as the ECU/ECM throttling up. 94

DC2BUD

No its not I bought a new ecu to try to solve this but nothing.

slyestguy

did you check your eld circuit, a bad connection there could cause fluctuations

DC2BUD

OK I just went ahead and tested the eld and circuit by the book and it checks out fine.

fcm

That is strange...

Because the problem is not there if the A/C is on, [ECU has engine idled up properly] but the problem is there if A/C is off would make me think it is A/C related, it sounds like ECU/ECM is idling the engine up and then down, but stays idled up when A/C is on.

If you have not already, check/redo the batt. to chassis and chassis to engine grounds, do not just eyeball them, remove them, clean both contact surfaces and reconnect, making sure they are tight, I would also check all the engine harness grounds, just in case it is just a poor ground someplace. 94

DC2BUD

Ok I just unbolted and double checked the grounds, and on top of that I took some 8 gauge amp power wire and ran it from the battery to the tranny, intake mani, thermostat housing, valve cover and alternator and still the bounce. The only engine harness grounds that i know of are the two on the thermostat housing are there more? Thanks again for the help!

DC2BUD

Just changed the coolant temp sensor under the dizzy and swapped plug wires with a friends and no change. I also tried unplugging the o2 sensor(got a cel of course) but it still did it. I don't know what else to do

Sr420Det

have someone who knows what there looking at, hook up a code reader and view data at idle, or a hondatas300 would show a lot more info. Have u changed ur throttle body to a know good one? sometimes the plates bend or warp, also at the throttle cable make sure the throttle plate is shutting all the way. Try a new chip too, could b ign or fueling

DC2BUD

I'm just waiting on my turbo mani to finish my turbo setup and I'm gonna have the shop tuning it try to fix it. It had the bouncing idle on the last motor with the stock throttle body/cable and different eprom chip. It has to be a sensor somewhere hopefully they can figure it out.

Sr420Det

with the scan tool u can view all the sensors and what they r doing. Go up to a autoparts store and ask to use theres, its free

DC2BUD

Just went to autozone and he said they don't have a obd1 scanner and obd2 scan tool wouldnt work on my car cause its been converted to obd1. I figured it would still work...

dragonvoi

did you find your fix? I have something somewhat similar and am curious.

DC2BUD

I brought it to be tuned and they said it was a bad tps sensor ground somewhere in the wiring harness and both the new and old tps sensor were bad also. Installed a good tps and wired a new ground to it, no more bounce.

Hyoriu

Sorry to bring this thread from the dead.

Just a question, wouldn't the bad ground for the TPS trigger a CEL?

Also. How much did you end up paying for the TPS to be replaced with them adding a new ground and how did they do it? I have the same problem as you and i've been driving with it for years now even after replacing the TPS with a good one correctly set.

tcout

On a random note. I bled some air out of my coolant system before which helped with my bouncy idle...