LS/vtec bad idle surge! please help

[integraboomer]

I have a 97 integra ls with an ls/vtec swap. b18b block and a b16 head. Runs good and strong. When i first got the car it would surge up and down till it warmed up then it would idle fine and steady at 800rpm, this was at the end of summer. when it got cooler it started to idle surge in neutral or any time you press the clutch in and it had really high idle. anyways i tried a new iacv because thats what the guy i bought the car from said it was the iacv. so i got another used one and it stopped surging and idled fine again well that lasted two weeks.. so now it surges all the time in neutral! and it idles at almost 2k! when i first start it tho is idles high and steady like its suppose to do but warmed up it will start surging. Ive done everything i can to try and fix this from trying different iacv's to cleaning the fitv. Any advice on what i can try will be greatly appreciated. Thank you

 

[CAFROG]

Maybe you can try to reset the idle. Get car nice and warm first.

Then shut it down

Unplug electrical on iacv

Restart car and it should idle really low

Turn idle adjust screw until it idles are around 500-550 with iacv unplugged

Shut car off

Plug electrical back into iacv

Unplug back up fuse for 30 seconds to reset ecu

Restart and see

Or you can unug iacv with engine running and see if idle drops (it should)

Or take intake pipe off and check for suction on the hole in the bottom of the throttle body.
The fitv should have no suction on that hole when car is at running temps

All stuff I suggested is at running temps

 

[integraboomer]

Maybe you can try to reset the idle. Get car nice and warm first.

Then shut it down

Unplug electrical on iacv

Restart car and it should idle really low

Turn idle adjust screw until it idles are around 500-550 with iacv unplugged

Shut car off

Plug electrical back into iacv

Unplug back up fuse for 30 seconds to reset ecu

Restart and see

Or you can unug iacv with engine running and see if idle drops (it should)

Or take intake pipe off and check for suction on the hole in the bottom of the throttle body.
The fitv should have no suction on that hole when car is at running temps

All stuff I suggested is at running temps

No matter how low i adjust the idle screw the idle still is high. its like there is no changing it bc something is causing the high idle. and the fitv hole sucks when warm sometimes.earlier it didnt suck and it did not surge. it also will seem to idle high but steady sometimes but when you rev it a bit it will then rev down and back up then start idle surging! seemsn like this all turned to crap when it got cold

 

[CAFROG]

So you are adjusting with iacv unplugged and resetting ecu like I stated?

Otherwise it won't permanently change

I had a problem where it was sensitive to revs too and lowering idle worked for me

But you fitv may be bad if there is suction

 

[integraboomer]

So you are adjusting with iacv unplugged and resetting ecu like I stated?

Otherwise it won't permanently change

I had a problem where it was sensitive to revs too and lowering idle worked for me

But you fitv may be bad if there is suction

haha my bad i re read your post over and over and saw that so yes i did try it with it unplugged. and i just unplugged the ecu jumper to reset it. works the same way right? but it seemed not to surge any but still high idle. then drove it for a while and had one or two surges. so it is probably going to get worse again. like everytime i put on a different iacv it holds idle for a bit then goes back to surging after a while. when i was reseting the idle didnt seem to lower it at all. Thank you for the help. nice to know theres someone out there who will respond.

 

[EG93sir]

I had a similar problem with my ls/v,turned out to be my timing was a little advanced,and my TPS voltage was higher than .4 volts at closed throttle.I removed the throttle body and removed the factory screws from the tps,found some 8 mm headed bolts to go back in,adjusted the tps while the engine was running at temp. and set the timing at 16 degrees by the distributor.Haven't had any idle issues in 3 months,even with the cold snaps we get here in Fl.Try these things and let us know what the results are.

 

[CAFROG]

Actually the above post should be taken into consideration.

Put timing at 16-18 degrees and check volts at TPS with key in "on" position but car off

Someone correct me if my numbers are off

0.5v with throttle closed
4.5v with throttle all the way open.

 

[integraboomer]

ok i am a dummy when it comes to timing. I know the differences between the ign timing and cam timing. ign you are rotating the dizzy and cam you are adjusting the cam gears. but dont want to do anything that i could dick up lol. and for the tps i just need a volt meter?

 

[serrilion]

TPS yes a volt meter works best, a digital one normaly... the dizzy is what there saying to play with... ether toward rad or toward fire wall i forget which way sadly.

 

[Dj211855]

Double check throttle cable adjustment!

 

[integraboomer]

It does not stall when you cover the entire throttle body. My girlfriend and I think it may be a vacuum leak. Any ideas?