Mudboi222

Hey guys me and my dad just finished putting in a new transmission for my 89 Jeep Cherokee Laredo. Everything went pretty well with the install untill we went to go start it up. It took me about a month to come up with the money to get a new transmission. Well while waiting for the transmission i would go out and put my battery in and listen to music and clean the inside. Well 2 days ago before we put the transmission in i was jacking up the jeep and didnt think anything of it but my battery was still in and we never did take my starter completly off and as i was jacking it i see smoke coming from the top of my hood. Im guessing the starter wire touched the frame or something and it caused my ground wire from the firewall to the back of my motor to melt in half. Well i got a new ground wire and put it in and checked around to make sure no other wires looked melted or burnt. Looked fine from what i could tell. Well 2 days pass we get the transmission in and now i try to start it and it just sits there and turns over and turns over. We checked to see if i was getting spark and im getting no spark at all. We did some test light checking and it led us to think it was the coil. Well i had a spare coil so i put it in. Still no luck. We can not figure out whats going on. Could it possibly be a relay or a fuse? If so where would it be? Could i test it? Could someone please help me out. Im still in highschool and have been waiting 2 months almost to get this thing back on the road. I would love to be able to drive to school the last few weeks that we have.

DFlintstone

Wow, Bummer! I'd Start here. You need a digital volt meter:

AC voltage CPS test; Small clips on the meter leads really helps.

Unplug the connector at the back of the manifold with wires going down to the bell-housing/cps.
Probe the two wires to the cps with the meter set on AC volts. (a 200 scale on mine).
Crank the engine and note the voltage. (jump it if your battery is low)

Mine somehow works with only .3 my wiring/grounds must be pretty spiffy. .5 seems to be a good mark. One article talked of .5 to .8. **Update, it soon failed. I installed Napa #css980 in my 90.**


There is more complete info in Crusier's stuff found in my signature. Also the "sensor ground" test is always a good start.

Mudboi222

Im having a strong feeling that its the CPS like you were saying. Your about the 5th person that has told me that and i bought the jeep from my uncle and he said about every month it wouldnt start and he would have to get down there and pull on the wires and move them around on the CPS till it started. I also went out there and unclipped the CPS by the firewall and tested one side of the clip and it has power going to it.

cruiser54

Here's how to test a CPS. It will have NO power going to it or coming from it unless the engine is cranking over.

Renix CPS Testing and Adjusting

Renix CPSs have to put out a strong enough signal to the ECU so that it will provide spark.
Most tests for the CPS suggest checking it for an ohms value. This is unreliable and can cause some wasted time and aggravation in your diagnosis of a no-start issue as the CPS will test good when in fact it is bad.
The problem with the ohms test is you can have the correct amount of resistance through the CPS but it isn’t generating enough voltage to trigger the ECU to provide spark.
Unplug the harness connector from the CPS. Using your voltmeter set on AC volts and probing both wires in the connector going to the CPS, crank the engine over. It won’t start with the CPS disconnected.
You should get a reading of .5 AC volts.
If you are down in the .35 AC volts range or lower on your meter reading, you can have intermittent crank/no-start conditions from your Renix Jeep. Some NEW CPSs (from the big box parts stores) have registered only .2 AC volts while reading the proper resistance!! That’s a definite no-start condition. Best to buy your CPS from Napa or the dealer.
Sometimes on a manual transmission equipped Renix Jeep there is an accumulation of debris on the tip of the CPS. It’s worn off clutch material and since the CPS is a magnet, the metal sticks to the tip of the CPS causing a reduced voltage signal. You MAY get by with cleaning the tip of the CPS off.
A little trick for increasing the output of your CPS is to drill out the upper mounting hole to 3/8” from the stock 5/16”, or slot it so the CPS bracket rests on the bell housing when pushed down. Then, when mounting it, hold the CPS down as close to the flywheel as you can while tightening the bolts.


Revised 01-26-2013

DFlintstone

Un-plugged, The Cps it's self should generate more than .35 (at the very least) AC volts while the engine is cranking. Do you have access to a digital meter? The $4 meter from Harbor Freight actually works. At least for a while. Since your Renix Jeep has no engine light, (stores no codes) (we) need a meter even more than folx with the 91 and on. Also if the CPS was installed during the swap it's pretty easy to bump it.

Mudboi222

Thanks cruiser54 I'll see what I can do. @DFlinstone I don't have one but I was out there messing with it with a old voltage meter tester. I didn't pay attention to the amount it was doing. Just to see if it was even budging. Also I'm pretty sure I did get stuff up in the cups installing it bc I was frustrating & was rubbing against the filthy a$$ transmission. I'll take it off & look at it tomorrow.

Mudboi222

Posted twice sorry.

DFlintstone

Ha! I see I was posting the same time as Crusier. (who I learned allot from). Come ON! $4 at Harbor Freight. Really you need a digital meter. You can pull your cps, set it on the table and look at it and and scratch your head...ain't gonna' help much though....The red "Cen-Tech" will work. The $4 HF meter is actually superior to the black $3 meters! (off ebay) A Fluke?

cruiser54

Required tool for Renix owners.

Mudboi222

Haha. We have one exactly like that. My dad went outside after work turned it over with the meter in the CPS plug. Got no volts at all. Pulled it out and it was completly thrashed...went and picked up a new one for $35, put it in and she started on the first try. Thanks for the help guys!

DFlintstone

And the Crowd cheers!!!!!....

Well done guys. (Yer maken' us look good). A whole bunch of crucial stuff grounds there on the dipstick stud. ECU,TCU yada yada. I strongly suggest you Save the link to Cruisers stuff and consider checking and cleaning grounds. Clean the IAT and IAC/throttle body. Check the adjustment of the TPS. I just adjust that tranny cable to about no play. (some). Button on top of the cable housing.

If/when you get slow starts or random dieing, check that $35 CPS! (Renix will always crank for just a sec before starting)

cruiser54

Isn't testing stuff fun?

Big willy

Hey man In the lower right corner of your picture there with the coin or whatever what is the name of that rod that hangs off the end of the throttle body and goes to your accelerator cable I think/ mine seems to have come very loose and I need to replace it but I don't know the name of it

cruiser54

Flintstone has the exact technical term for it. He'll respond once the sun goes down.