96xjshaggy

So i had acceleration problems and i changed downstream o2 and tps and when i changed IAC i started my car and it is idling really really high so bad i county keep her running. My upstream o2 is bad could this be a cause??

RenegadeStang

Clean out your throttle body. Make sure you don't have any carbon build-up in there.

BstrdXJ

Test your IAC and TPS. Also, your TPS needs to be "set". You can't just throw it in and it be correct. At the same time, clean everything really good. Throttlebody and sensors. Don't wiggle/turn the IAC sensor tip, it's fragile.

An easy way to test your IAC is to pull it, with it still wired in, and have someone start and lightly accelerate your XJ. If the tip of the sensor doesn't move, it's bad. Look up a guide to test and correctly place your TPS.

tssguy123

Did the high idle start as soon as you changed the TPS? I've heard of people getting bad TPSs and it causing high idle.

only Renix TPSs were adjustable, 99% sure.

96xjshaggy

I replaced the IAC after everything else. before IAC it idled/ran fine, except for the acceleration problem. I got her tested at the shop they said bad upstream o2 and the IAC isn't reading right. So i replaced it and my idle was thru the roof unplugged it while running still thru the roof put old one back in idled fine. I will check if the pin moves right now.

96xjshaggy

So i just did the test and the tip moved every so slightly when i gave it gas.

tssguy123

You could try resetting the computer. IE, remove positive battery terminal and touch to ground for 30 seconds. Make sure the o-ring for the IAC is in good shape.

That's all I've got. Someone else can step in now. How high is "super high" anyway?

belvedere

I agree. The position of the new IAC may be quite different from where the position of the old one was when it was removed. I wonder if the computer might be a tad confused.

96xjshaggy

High enough to kinda scare me to shut it off right away lol. I wanna say at least 3k rpm

96xjshaggy

So i put the new IAC back in and reset the ECU and it worked. No super high idle thank you!! But my acceleration still sucks lol. Seems like my tranny doesn't want to shift. I'll get on it it will go then when it goes to shift it just kinda bucks i guess you could say. Then I'll let my foot of the gas and back on it will kinda shift and hesitate more then go. Idk lol help would be appreciated thanks.

salad

Test TPS, adjust TV kickdown cable, check fluid level and condition

tssguy123

No idea what's going on there. My Jeep did the same thing after I reset the ECU after doing a tune up. It then stopped doing it. You've probably already done it, but adjust the kick-down cable just in case. Also, check the TPS if you have a meter. It's very easy and possible you got a dud.

x2 on this. My transmission was shifting very sloppy/slowly. New fluid (dex/merc) can go a long way.

96xjshaggy

Ok I'll adjust the kickdown cable after work tonight although i don't think that's the case . I will also test tps (could've got a dud). Fluid level is good. Condition?? And my upstream o2 is bad. it just runs so good when i baby her as soon as i give it any hard amount of gas no matter what speed 0 or 60 shell bog down not go anywhere. And it makes a weird clunk noise when it's bogging down.

freegdr

Did ya make sure o ring on iac there ....

tssguy123

He said it was fixed, just needed to reset the ECU