High idle after swap

dwreck30 · Post by **dwreck30** » Sat Sep 16, 2006 2:04 am

After doing a swap between to SS's my car idles around 3k. It seems to get better after it warms up, but doesnt go below 2200 or so. Strangely enough there are no CEL's

My swap was a '91 SS 5spd motor/tranny into a '93 SS 4EAT.

dzx · Post by **dzx** » Sat Sep 16, 2006 2:44 am

Check the idle screw that isnt supposed to be moved. Also, my car idle's around 2k when I turn it on up till the point where its warmed up and I'm at a complete stop for a while. Weird but the idle rpms drop down to normal then. My car has a 4eat to manual swap.

dwreck30 · Post by **dwreck30** » Sat Sep 16, 2006 3:35 am

Before I took the motor out of the '91 everything was fine. I don't really want to mess with the idle screw if thats not what it is.

dzx · Post by **dzx** » Sat Sep 16, 2006 9:20 pm

I'd double check the wiring then to make sure the car doesnt think its still an automatic.

soloracer · Post by **soloracer** » Sat Sep 16, 2006 10:44 pm

Vacuum or intake leak after the throttle body?

Imprezive · Post by **Imprezive** » Sat Sep 16, 2006 11:14 pm

could be something as simple as your throttle cable getting hung up a little bit. Also check the throttle body throttle plate inside to make sure there is no grease/grime holding it open a little bit.

+1 for checking to make sure it isnt thinking its still a 4EAT SS.

dwreck30 · Post by **dwreck30** » Sun Sep 17, 2006 12:15 am

There shoudn't be anything left telling it that its a 4EAT. I did finally cut the AT/MT indentifier and that helped a little. Now it will idle down, but then it will start running really rich, to the point where it almost dies. When it does that it I can give it just a little throttle and it will idle fine for about a minute. and then do it again.???

It is throwing codes now, but the only one that would maybe be it is the TPS. I got codes 14,15,17 and 31(TPS). I checked the risistance and I got 8.2k between pins 1&2. My other one measured about 8.9k.

Post by **Legacy777** » Tue Sep 19, 2006 4:08 am

The AT/MT identifier needs to be cut, which sounds like you did that.

You also need to deal with the neutral switch, which may or may not help your issue.

Have you read my awd & 5spd write-up? There's a sticky in the drivetrain forum. I'd suggest looking over that, and take care of the wiring issues related to the AT to MT swap first.

dwreck30 · Post by **dwreck30** » Thu Sep 21, 2006 1:11 am

I was hoping you would chime in. I think you might have found my problem too. Just to make sure on the B36 connector, is the wire I have to snip green/yellow? I'm glad their are people that have done this before.

Post by **Legacy777** » Thu Sep 21, 2006 3:35 am

The wiring diagram states the color as LgY

I don't have my manuals in front of me to determine the wiring color, but I think that is green with yellow stripe.

dwreck30 · Post by **dwreck30** » Thu Sep 21, 2006 5:08 am

I saw that and then I snipped it. Didn't make a difference though. I have done everything from you sawp guidline except for the cruise control stuff. Would this be causing problems?

If I start it cold it will idle rich right around 1k then when it warms up it wilkl jump up to 2k or higher. After about a 2 minutes it will work its way to a normal idle for a second then go rich and barely idle. If I give it gas at any point in all of this my CEL will go off and then come back on after I let off the gas. Iv'e driven it around like this and it will acceleratly pretty normal up until 4k then it misses<-when I'm floorin it. If I gently take it up it will keep on going without any misses and CEL's.???? Thanks for all your guys' help.

Post by **Legacy777** » Fri Sep 22, 2006 4:20 am

The cruise shouldn't matter

What codes are stored in the ECU?

dwreck30 · Post by **dwreck30** » Fri Sep 22, 2006 9:44 pm

I got 14,15,17 and 31. I actually mentioned that above. I also checked the resistance on the TPS too.

Post by **Legacy777** » Sat Sep 23, 2006 6:35 am

Sorry, must have missed where you mentioned the codes.

That's weird all those injector codes are popping up. Wonder if the injectors are different.....

dwreck30 · Post by **dwreck30** » Wed Sep 27, 2006 3:24 am

Would there be any bad effects if I tried my '91 Turbo ECU in my '93?

Post by **Legacy777** » Wed Sep 27, 2006 9:34 pm

Shouldn't be.

dwreck30 · Post by **dwreck30** » Fri Oct 06, 2006 2:36 am

Ok I think I found the problem. I went to change all the plugs and when I was putting in my last one the plug got tight enough to crush the washer then stripped. Uh oh!! I will be replacing the head with a spare one w/ 182k. Unless someone has had good experiences with Helicoils that would change my mind.

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High idle after swap

High idle after swap