Tire_rips

Hi, hope everyone's doing good.
I just bought a Jeep Grand today.
It's a 1994 5.2 v8 limited. It's got a pro comp lift kit installed with some LT245/75/R16 tires on some eagle alloy wheels with bead locks.

I went to take a look at this thing the other day and couldn't pass it up for the price. It does need some TLC though.
So I need all the guidance I can get. I'm mechanically inclined, I build street/ track cars for hobby. I'm just inexperienced with these Jeep grands.

First off it doesn't idle. If I take my foot off the gas it will fall below 500rpm and after a few seconds of stumbling, die out. It starts up easily. I just barely need to touch the pedal to keep the rpm at around 800 or so.
It's got completely stock intake and exhaust.

Second, I checked and tested all the fuses on the side of the dash on the passenger side and the ones under the hood and everyone seems fine but there are problems.
* the cigar lighter seems unused but doesn't work. I tried cleaning it out with a wire brush. Tried connecting a phone charger. Nothing.
*The digital compass on the overhead display doesn't show anything.
*When I turn on the radio there is no display, no sound or noise at all, but the antenna goes up and back down when it's off.

Other than that everything seems good to go.
The A/c works, power steering works fine but the rack is leaky.
Compression on the engine is good and there are no leaks. Just a bit from one of the valve covers but it's not reaching the ground and is very minor.

I'm also in need of new tires. I don't want anything so oversize that's going to make my gas mileage even worse and nothing so big they'll rub under full lock to lock steering. I'm going to use this on light trails, nothing major. Just for entry level fun. Azusa, angeles crest, pulling a boat around. Nothing to loud for the street but enough tread to handle some loose shallow dirt and some light mud.

So got any help for me out there?
Some recommendations on tire size, model, or brand??

Thanks in advance from an eager newbie.
Cheers.

Tire_rips

Forget about the overhead display. I smacked it right now and it works just fine now.

As for the radio. I forgot to mention it's the Infinity gold cd player with 5 band EQ.
When you turn the power on for the radio the eq lights up and if you push the eject button the CD door opens and the mtoor sounds as though it's spinning but I can't put a CD in. It won't go. I checked to make sure one was not stuck in there and it is not.
There is no noise or sound at all when you try and change stations. The display does not show anything.

ol"blue

The idle issue is probably caused by a dirty/defective TPS.

DieselDaze

if the pcv is disconnected or plugged your idle issue will be just as you described.. recheck all your hoses, or spay them down with the car running for vacuum leak.

ol"blue

A disconnected vacuum hose will usually cause a lean mixture and a high RPM idle.

Tire_rips

Yeah the first thing I did was go over all of the vacuum lines. It doesn't seem to have any issues there.
I also sprayed around with some WD40 while the idle was maintained and it didn't affect it so no leaks as far as I could tell.
I checked the PCV and it seems to be fine also.

My first guess wasthe TPS sensor just because of how it's acting.
Sometimes it will idle okay for a while, most of the time not.
And the first, maybe 16th of an inch of pedal has no response to the engine RPM.
Other then that it has plenty of power and drives fine going down the highway.

Tire_rips

I've been searching for wiring diagrams. Does anyone know whare I can find a wiring diagram for the stereo system?
I've got the Infinity Gold with CD only.
I'm pretty sure it's the unit itself that has the problem but I'd like to test all the wiring.

Also I'm searching to find the specs for the TPS sensor so I can test it but I'm not finding it yet. Anyone know?
Or know where there is a repair manual online??

ol"blue

You can't really go by the pedal because an old cable has tended to stretch and can have a little slack in it.
It could also be your EGR valve. Disconnect the vacuum hose from the EGR valve and attach a hand-held vacuum pump directly to the EGR valve. Start the engine and apply 15 in.-Hg of vacuum to the EGR valve. With the engine at idle speed, the idle speed should drop considerably or even stall as vacuum is applied. If the engine speed does not change, a faulty EGR valve or plugged passages in the intake manifold are indicated. Watch the stem on the EGR valve for movement as you apply vacuum to the EGR valve. If the stem doesn't move or if the EGR valve fails to hold vacuum, replace the EGR valve. If the valve opens and the engine does not run rough or stall, remove the EGR valve and check the passages in the EGR valve and intake manifold.
This info comes directly from my repair manual.

ol"blue

I don't have a pdf manual for the ZJ's. Sorry. I only have a Haynes. It's better than nothing though.

Tire_rips

I was about to ask about the EGR next but you answered it dead on.
Thanks again.
I'm free all day for trouble shooting so I'm going to go test it out right now.

Would you be able to check the specs on how to test the TPS and what range it should be in? If it's not to much trouble.

Thanks again.

ol"blue

Instead of me typing it out, I'll scan it and send it to you in a Private Message. Just give me a couple of minutes.

ol"blue

I don't have a diagram for that in my manual. Try this. DCP-Wiring.pdf (application/pdf Object)
Or this. The Install Doctor - The Do-It-Yourself Car Stereo Installation Resource

Tire_rips

Thanks for all the info Ol Blue.
I need to get a repair manual. I went to the local stores this morning and nobody had one in stock so it'll be until Monday or Tuesday till I get my hands on one.

I did try unplugging the tps sensor and it seemed to run better. Or at least it didn't die stall out.

ol"blue

Glad to be of help.