installed JG edelbrock intake mani. on gsr, realized some vacuum connections and some plugs may have been wrong, caused high idle/some bucking at 1500 rpms. we checked all vacuum leaks and plugs everything is correct now, my idle is not at around 1400 and surges up and down from around 1400 to 2000, the car idles fine when you start the car, but after a little throttle is given the surges start, we have checked over everything atleast 3 times, here is what we have checked

1. checked all lines and plugs, no leaks, everything is hooked up right
2. sprayed cleaner on everything, no leaks
3. let car run to get air out of cooling system
4. varified sensor connections with manual
5. switched iac valve with working one, still did it
6. switched throttle body with working one, still did it
7. put iac on another car, car idled fine

here is what we know:

the iac is good
no leaks
alll hoses run right
all sensors are right

my car was throwing a 7 and 14 CEL code, then it was throwing 1, 7, 10, 14, then we reset the computer and now we only have code 10. we have tried everythind and still have the idle surge! what could it be!? please help!

 

Code 10 signifies Intake air temperature sensor. A code 10 sensor will make the car run at a fixed temperature, causing the engine to run either lean or rich depending on the atmospheric conditions (cold and hot weather). It will not effect the idle per say, but it will effect your air/fuel ratios.

As far as your problem goes, you have a vacuum leak i am sure. Check around your intake manifold flange area, where the intake manifold bolts up the head. Take a plastic bag and let it float over the surface of the intake manifold. If there is a vacuum leak it will suck in the bag and correct the idle. I think you might have a non sealing issue with your gasket and/or gasket area.

 

i would definately have to agree with boosted hybred, my car had a vacume leak and it was doing the idle surge thing especially when i let off the gas it would surge three times then smooth off. recheck all vacum hoses for leaks and possible cracks or tears, and check the seal of the manifold gasket. best of luck toyou gloria

 

did you check the pcv valve at the black box on the back of the block? i had that happen to me on a intake mannifold install. good luck

 

it sounds to me like a sensor is not plugged in or bad or swapped with another thats the same plug. has to be on the intake manifold for sure.

 

Hey i was working on this car, PCdc2 was sitting in a chair picking his nose, and i said "yo tighten the manifold" and he did, but i think some of the boogers got on the gasket, therefore causing a non sealing issue.

I think we need to take the manifold off and reseal the gasket and clean off his boogers

 

see the thing is, if it were a vacuum leak wouldnt it surge at idle immediately? because right now this is what happens

1. we start the car, has high idle 1300-1400 rpms
2. give it a little throttle it drops back down to the same rpm but starts surging

we've even swapped a few plugs and the surge has changed to more rapid surges and stuff that's why im questioning a vacuum leak....

 

i had the same problem, i had to loosen my throttle cable. i found out because if i pulled up on the gas pedal the idle would go down

 

I was going to mention the same thing....did you adjust the throttle cable??

If it is pulling the blade open just a little bit, the idle will surge. Check that out, loosen up the thotle cable until there is nothing up slack between it and the throttle body. Then start it up and see if the surge is still there or not. Then do the final adjustment of the throttle.

 

THe cold start idle should be that high, and when the car reaches normal operating temperature it shoudl sit right at like 800-950ish RPM's.

Did you fgts try like i told you adjust the fast idle controll valve, i sure hope you didnt reuse your IM gasket.... Trouble shooting pwnz JOO!!!

 

Moe, maybe if you knew what a wrench was, i'd listen to you.

If you read the post, you will see that we switched throttle bodies with mine. New gasket was used.

We are gonna take off the IM, and put it back on, because there is nothing else it could be except the ECU.

 

Yea dont listen to me i dont know ****...

What does the fact that you switched TB's have to do with anything? I thought you couldnt bolt up a B18c TB to a B16, but whatever. Check the voltage of the TPS, just trouble shoot numb nutz or try the fast idle controll valve like i said.

If you think theres air in the system then the fast idle controll valve could have done it. If theres air in the coolant system it can losten the adjustment screw.

Also theres problems with some aftermarket IM's, they will not bolt to the head propperly and cause leaks. With the skunk 2 IM you have to machine it down or else it will not fit on the head properly, in some cases.

And whats a wrench?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Moe &raquo;</TD></TR><TR><TD CLASS="quote">I thought you couldnt bolt up a B18c TB to a B16, but whatever. Check the voltage of the TPS, just trouble shoot numb nutz or try the fast idle controll valve like i said.
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Nice thing about Honda's....all the throttle bodies use the same bolt pattern.

Did you check the throttle cable? When I did a manifold swap...I had an idle surge, and it was from the throttle cable pulling the butterfly open. It was barely pulling on it...but that's all it needed.

 

with my vacume leak my idle was fine it didn't surge until i gave it gas to either drive or rev the engine then it would surge two to three times then settle down again. But i hope that by now you had found the problem, good luck gloria

 

you have the connections of a different sensors try to find another sensors plug in that is just like that one and switch them