Really need advice on my 99XJ

[Hawk]

Today I pulled the header/intake to swap in a new header, since mine was cracked. My jeep sounded like a diesel. I'm sure most of you are familiar.

I got everything swapped fine, but after I hooked it all up, when I start it, the engine revs all the way up (with the throttle body cables disco'd, so it shouldn't be a TB problem at all). It bounced off the rev limiter once, so I shut it down. I started it twice more and it tried to do the same thing so I killed it really fast and I don't want to mess with it anymore tonight.

I used PB blaster to clean the injectors and the little holes where they go, but I cleaned the PB out of the holes and sprayed white lithium grease in there before I put the rail back on.

I reused the old manifold gasket, since the piece of trash I got from oreilly had about 1/8 inch of intrusion on the exhaust ports. (LAME!)

I unplugged all the injectors and tried again to start it, and it didn't fire at all. So I guess the injectors are going balls out when I start the thing and pumping it full of fuel, although my TB isn't opening or anything.

Also, it's running completely "normal" when it does this, meaning, no backfire, no sputtering, sounds the way it should sound.

Help... :dunno:

[Hawk]

Anyone have a buddy they can call on a Sunday morning and give my number to?

636-584-5181

[jpdocdave]

its not gas being pumped in, its gonna be air. vacuum leak. and one that large is usually the brake booster vacuum line, easy to forget to reinstall. it is unlikely a vacuum leak that big would come from that intake gasket, but it is a terrible idea to reuse it.

[Hawk]

I'm going to take off the old gasket anyway. The reason the new one didn't fit is because apparently mine needs the one for the 98. Their 99-01 have the same part number. Wife is on her way to get it while I tear it all back apart.

[jpdocdave]

good idea. check your vacuum lines, and did you take the throttle body off for any reason? if you did, replace that gasket.

 

all the injectors aren't gonna dump too much gas in, and too much gas will give you the opposite effect. chances are a large vacuum leak was happening.

[Hawk]

It's all taken back apart, waiting on the wife to get back with the new part. I had all my lines and everything hooked up correctly, it had to be that gasket. This time I'll clean it really good with carb/choke and let it all evaporate, then put it back together.

[jpdocdave]

let us know what happens

[JeepcoMJ]

make sure you actually remove the old gunk from the old gasket.

[Hawk]

Turned out the gasket was fine, it was the fact that I didn't have the intake seated on those two pegs. Didn't even know they were there. Bent my intake enough that when I put it on correctly it still had a bit of a leak, so I put on a spare I had, and I'll have to take my original to the shop and have it squared. It's running great now.

I did put a new gasket on, by the way.

Thanks for the tips, guys, always appreciated.

[jpdocdave]

glad you got it fixed, thanks for the post to. i hate not knowing how something turns out.