Ian96XJ

So I finally installed the 99+ intake manifold, Doug Thornley headers, 703 injectors, and a 63mm TB. I was expecting a bit of roughness after I reset the ECU (positive & negative cables touching for 30+ seconds, reconnect, car on, lights on, lights off, car off). What I got is idle at 2500 RPM and rough shifting points.

For those of you who've done this mod, is this what you got? I'm wondering if maybe a vacuum line is hooked up wrong. Or if there's a leak somewhere. Or maybe this is to be expected and it'll all smooth out in 50 starts. Should I just unplug the battery overnight for a sure ECU clear?

I THINK I feel the shifting smoothing out, but the high idle hasn't budged yet. I've done at least 10 starts since install.

Thanks!

Ian96XJ

After doing some research, there seems to be a possibility my TPS isn't functioning correctly. So when I get a chance, I'll go out and see if maybe I didn't hook it up correctly or maybe I'll clean it real good with some electrical contact cleaner.

Donnie_K

I have the 99 intake, an apn header, and 703 injectors and mine idles right around the 800 rpm it's supposed to idle at.

Bustedback

Mine idled at 750 after the swap as it did before the work was done. Check for vacuum leaks.

Ian96XJ

Okay, thanks guys. Now I know something's wrong. And knowing is half the battle. (GI Joe!)

fishtaconc

For your shifting issues, google TV cable adjustment, it may have gotten out of whack dis/re connecting it.

Ian96XJ

Haha! Someone else PM'd me with the same suggestion.

Just so everyone knows, I did the adjust on the kickdown cable. BUT, I was the one who pushed down on the accelerator pedal. I'm starting to wonder if my buddy was pushing the adjustor button like I told him to. I wonder if there's a way to do it solo?

JeepCoMJ

Move throttle by hand while adjusting.

And clean your idle air sensor.

Did the intake get seated flush? Some headers won't let it sit flush without grinding a bit off of the runners

TheJerm

x2, I've had to massage 2 out of 3 99+ intake swaps with headers to make fit correctly

413maxwedge

Yup check for a intake leak at the head,(gasket area).

Ian96XJ

Readjusted the throttle cable. That wasn't it. Next, I'll clean the IAC. If that doesn't work, I'll move on to the TPS. I looked at the headers and they LOOK flush, but I didn't spray WD40. I hope it's just the IAC and maybe a new o-ring for it. I'll let y'all know.

fishtaconc

Don't twist,push/pull the pintle(plunger) on the IAC, you will be buying a new one.

Ian96XJ

All I plan on doing is dousing it in copious amounts of carb cleaner. With all these warnings, I'm afraid to even take a brush to it! Lol

Ian96XJ

Well, the IAC valve wasn't it. I uninstalled it and it was pretty filthy. After a bit of cleaning, I tested it. At least I think I did. I thought I read that I could test it by hooking it up to the plug and then turning the car on (but not starting) and that by doing so, the IAC valve would do something and would look different. Nada. So I took it to the parts store intending to find a new o-ring for it and ask about it. The parts guy saw it and said it didn't look right, that it was "sticking out too much". He showed me a new one. Sure enough, it looked different. So I said, "What the hell." If it didn't fix my problem, the worst is that I have a new IAC valve. Of course you know, the worst happened.

(new & old)


I reset the ECU and checked all the vacuum lines and everything looks okay. I guess next I'll check the TPS. And if THAT isn't it, then I'll be resigned to checking for leaks at the manifold gasket, which will involve taking stuff apart again and a spending a whole lot of time I could be using out in the desert.

At least the shifts are smoother now after the new IAC. But it still idles at 2000 rpm.

Ian96XJ

PS. What's safe to spray these days to check for vacuum leaks? I heard WD40 doesn't work anymore?