Cascade Crew

fiveoformula · Posted: Thu Oct 17, 2013 4:26 pm Post subject: Cascade Jeep Tech!

maybe since were also a jeep forum now, maybe you guys can help me. Laughing

It's an '88 Cherokee 4.0L Renix with 173k on it, replaced some grounds and replaced TPS due to high-idle problems on warm start-up. I also had done an ignition tune-up and more recently a fuel filter.

TPS cured the high idle problem, yet I seem to have a new issue since I replaced it, very hard cold starts, the jeep idles rougher, seems to be slightly down on power, and occaisional stalls when idling in gear cold (such as after coming to a stop, acts like someone shut off the key)
You guys think defective TPS? or maybe its fluke that this all happened after replacing TPS?

chevymad · Posted: Thu Oct 17, 2013 5:05 pm Post subject:

Hook a volt meter to the tps signal and check it. Best if you have a graphing meter. You're looking for dropouts while you cycle it through its range.

aaron_sK · Posted: Thu Oct 17, 2013 7:57 pm Post subject:

Is this an adjustable TPS?

fiveoformula · Posted: Thu Oct 17, 2013 8:30 pm Post subject:

This is an adjustable one.. I have adjusted it a few different ways without feeling or noticing much difference.
I need a new volt meter that doesn't read 2-3v too high to check it out.

fiveoformula · Posted: Fri Oct 18, 2013 8:36 am Post subject:

Just noticed a new symtom last night, now suspecting something spark related. I started it last night and got up to 45mph without much warm-up time like it usually gets.
Right after it shifted into O/D it has a dead miss that jerks the whole rig at cruise speed. Doesn't seem to do it when warm though

chevymad · Posted: Fri Oct 18, 2013 11:31 am Post subject:

Crank sensor? They're a known jeep issue.

Dewey316 · Posted: Fri Oct 18, 2013 11:35 am Post subject: Re: Cascade Jeep Tech!

Come on Brandon, you didn't point out the obvious.

fiveoformula · Posted: Fri Oct 18, 2013 1:04 pm Post subject:

fiveoformula · Posted: Fri Oct 18, 2013 1:48 pm Post subject: Re: Cascade Jeep Tech!

Dewey316 · Posted: Fri Oct 18, 2013 1:49 pm Post subject: Re: Cascade Jeep Tech!

fiveoformula · Posted: Fri Oct 18, 2013 2:05 pm Post subject:

Oh whatever... Its a classic! I still have the original "AMC" keys to it. Nothing chysler about it. Cool

Twilightoptics · Posted: Fri Oct 18, 2013 5:00 pm Post subject:

Actually, the Renix models are more reliable, just tougher to fix when they do break.

That one shouldn't have a crank sensor, it should still be distributor. Make sure TPS is good, then verify fuel pressure.

Map sensor vacuum line is known to break.

chevymad · Posted: Fri Oct 18, 2013 5:15 pm Post subject:

They have both a crank sensor and a distributor Paul. Distributor is just a cam sensor and spark distribution device. The crank sensor triggers the ignition and timing of the motor.

chevymad · Posted: Fri Oct 18, 2013 5:18 pm Post subject:

Oh and Paul's right about the renix. They work pretty well, just suck to diagnose or buy parts for.

Twilightoptics · Posted: Fri Oct 18, 2013 5:18 pm Post subject:

Really? I don't remember seeing one on mine. If that's the case, yes put a crank sensor on it.

chevymad · Posted: Fri Oct 18, 2013 5:52 pm Post subject:

It's hidden upper drivers side of the bellhousing. Jeep used an oddball flywheel trigger too, which is why most aftermarket ecm's like megasquirt don't work.

QwkTrip · Posted: Fri Oct 18, 2013 7:55 pm Post subject: Re: Cascade Jeep Tech!

fiveoformula · Posted: Fri Oct 18, 2013 10:03 pm Post subject:

Yeah the crank sensor seems to make all kinds of crazy driveability problems when they start going out.. On the HO's and renix from what I read... The renix jeeps seem to have had under-engineered grounds from the factory that cause intermitten weird problems now they're old and falling apart.

Twilightoptics · Posted: Sat Oct 19, 2013 12:42 am Post subject:

Bah that's over analysis by the forums. My 87 had 278k and I don't think the grounds were ever touched.

Any make with a faulty ground willl cause issues.

DBL_TKE · Posted: Sat Oct 19, 2013 10:43 am Post subject: