Problem with my Jeep

[Z Ya Later]

For the past few months now I've been having trouble with my Jeep. I put a Howell EFI kit on it, which is basically the Chevy pickup EFI right down to the PCM (of course there are some custom parts). A few months ago, as I'm driving home, I notice the SES light come on and its idling pretty bad. Pulled the code...code 33, MAP sensor reading low or no vacuum (or something to that effect). I hooked up my vacuum test guage today (finally got one) and it oscillated between 13 and 14" of vacuum, read down to 8-10" when I revved the motor. But, when I pulled off the line (essentially creating a vacuum leak), the motor started idling much better, almost where it should be idling. Any ideas? Thanks in advance guys.

[Trash man]

try puttin a new line between the map and the intake and see if that works

[Z Ya Later]

try puttin a new line between the map and the intake and see if that works

I actually relocated the MAP to the TB at the suggestion of the Howell Techs a couple months ago...still nothing. The MAP was originally on a vacuum line which connected to a port on the intake manifold, as you pointed out. This port is also where I connected the test gauge directly, not using a T-junction.

I did forget to mention that this all started after I came off the freeway coming home from a buddy's house. Since there's no OD, the motor revs higher down the freeway at ~75.

Could this be an intake manifold leak? Any way to check? Maybe something else?

[94 formula]

You can always do the old trick of spraying a small amount of starting fluid around the intake and listen for the motor to rev that found the intake elbow leak on my firebird. Also you may want to ask this on www.jeepforum.com theres some pretty knowledgable guys over there.

[Z Ya Later]

You can always do the old trick of spraying a small amount of starting fluid around the intake and listen for the motor to rev that found the intake elbow leak on my firebird. Also you may want to ask this on www.jeepforum.com theres some pretty knowledgable guys over there.

Thanks man, I'll give that a shot when I get another chance to pop the hood on Thurs. Also, isn't there a trick with adding ATF into the intake and watching for smoke?

I did post this on the forums at www.ifsja.org, which also seems to be a pretty good board. I'll give the forum you suggested a try too, thanks.

[Joe 1320]

13-14 is low at idle. You should be in the 17-18 range. Check for vacuum leaks! go over everything from the brake booster to vent lines..... anything that uses a vacuum source.

[Steel2686]

The main problem is.... It's a Jeep.

J/K

Seriously... I immediately thought of a vacuum leak. My Bravada had a very similar problem last year. It was idling very rough, almost to the point of stalling. Found a vacuum leak by the firewall (it was a vent hose). I used the soapy water trick on all the hoses to check for it. It's tedious, but it worked.

[Z Ya Later]

The main problem is.... It's a Jeep.

J/K

Oh ha ha ha

Anyways, I'll try the soapy-water or starting fluid trick. I do have a friend who says that the AMC motors are notorious for going through intake manifold gaskets (though I've never experienced that problem...yet). Maybe I'll start there. Any other suggestions? Would the ATF trick work? Thanks guys for your help so far (except for 02 WS6...I just hate that guy...lol )

[Joe 1320]

Oh ha ha ha

Any other suggestions?

Propane. Just don't smoke while you are using it.

[wolfdogs]

13-14 is low at idle. You should be in the 17-18 range. Check for vacuum leaks! go over everything from the brake booster to vent lines..... anything that uses a vacuum source.

what he said... thats way too low.

[Z Ya Later]

Propane. Just don't smoke while you are using it.

I think I'll stick with starter fluid, thanks lol. I'm assuming carb cleaner would work too, yes?

I had one of the guys on www.ifsja.org tell me it was because its running rich...isn't that the symptom, not the cause?

[Steel2686]

Thanks guys for your help so far (except for 02 WS6...I just hate that guy...lol )

Like I don't hear that from my wife every day...

[Z Ya Later]

Like I don't hear that from my wife every day...

Well, as long as its not just me saying, then I don't feel so bad lol

Hey, could it be possible that, for some reason, the timing chain slipped and is causing all this? Or is that something I should check last?

[Steel2686]

I wouldn't rule anything out, as a rough idle can be caused by a million things... but a vacuum leak is the easiest, and most likely culprit.

[Z Ya Later]

And I hope its something simple too, like a hose just popped off. I need more complications like I need another hole in my head