12mpetru

I have three questions. First off, i bought a used jeep, a 1988 cherokee. My first question is, when i start it i have to like hold down the starter for like 8 seconds untill it starts. You would think that if you held it for like 4 sec, and bumped it again it would start right up, well not with my cherokee you have to hold it. Any thoughts on what that is? A battery? The Starter?

My second question is, Since i have the older jeep, the radiator does not have a cap on the radiator its self, it has its own separate reservoir near the firewall on the passengers side. How much is it meant to be filled up? there is no markings on it that say full or any thing. You can just see a line half way up where they fused the top and bottom plastic pieces together.

And my last question, After i have my freaky start, it idles high. If its in park, or neutral. But as soon as i put it into drive or reverse, or 1-2 it lowers the rps. I know this probably is not a big problem, would just like to know why.

New to the forum and offroading, im a major newbie lol, i tried to look this stuff up but i couldn't find it.

12mpetru

oh and sorry, Also. My oil pressure gauge is like pinned past 80. It never moves... Could that be just the gauge. Or could it be the sender or sensor?

Radi

You have a "Renix" jeep. You'll see that referred to often. The engine controls were a Renault-Bendix collaboration, shortened to "renix". Some folks prefer that setup over the later Chrysler electronics, it is pretty simple to troubleshoot with a simple DVM once you learn the quirks.
Cruiser54 has a set of write-ups you'll want to check out regarding that vintage covering ground and connector refreshing. you may want to get those things done.

One of those Renix quirks is that they need to see a certain engine rpm for a certain length of time before the engine will fire. They don't start instantly.

Does the idle come back down after a few moments if you let it sit in Park?

Radi

Most likely a bad pressure sender, located near the oil filter. It happens a lot.
Try unplugging the sender connector, then try grounding it. (both with the key ON) If the gauge still doesn't move, the problem is the wiring or the gauge itself.

12mpetru

No it does not, it just stays there, maybe carbon build up on the throttle body or something?

12mpetru

ill have to try that, thanks

cherokee90

Google how to adjust your tps sensor for the idle, oil psi gauge new sending unit. And holy crap you use the word like alot...

12mpetru

ill have to try that, thanks

DESERTXJ206

Cruiser54 has write ups on how to adjust your throttle positioning sensor. Also you may want to carefully take out the idle air control motor located on the side of your throttle body. Clean that with a soft bristle brush and some Carb cleaner. (Do not twist of put any force on the pintle needle itself you can ruin the sensor).

Clean your throttle body out aalso. That's is a few things to start with your idleing issue.

letinsh

Here are the write-ups Cruiser54 did for our Renix XJs.

Just as a suggestion, I'd do the "ground refresh" first, then the "C101 connector refreshing" next.

For your idle problem, also in that write-up is a method for testing and adjusting your TPS (throttle position sensor). Right next to it, in the throttle body, is the IAC (idle air control) valve. You can take that out and clean it.

Those would be the first steps in figuring out your problem. It could be a vacuum leak, but I'd start with the TPS and IAC. As for the coolant bottle, I'll have to pass to someone more knowledgeable. The first thing I did to my Waggy was to get rid of that old "open" style system and switch to the newer "closed" system ('91 and up).
Check my build thread if you want to see the blow by blow conversion (link is in my signature).

Good luck - the journey is just beginning for you well worth every turned bolt

letinsh

dang, you got in before I did

DESERTXJ206

Ha ha yeah I'm on the mobile app so getting links is difficult on my phone. You got me on that part.