Flex Plate Renix

[setht303]

I have an 88' XJ and have replaced the flex plate with part # 04423 from Advanced Auto parts. I've heard that those are junk after I had already put in the transmission and it didn't start. Replaced the CPS and still no spark. So, I ordered a "OEM" flexplate from quadratec part # 33002675 and before I put it in, I'm just trying to make sure that this part is correct. It looks so damn close to the one I just took out.

Anyone replaced a Flexplate and maybe know where they got their part and maybe the model number? Any help would greatly be appreciated and maybe save me like 8 hours of dropping the tranny again.

Trying to get to moab in a week. I would have had plenty of time if this hadn't happened.

Seth

 

[thanasi85]

I have an 88' XJ and have replaced the flex plate with part # 04423 from Advanced Auto parts. I've heard that those are junk after I had already put in the transmission and it didn't start. Replaced the CPS and still no spark. So, I ordered a "OEM" flexplate from quadratec part # 33002675 and before I put it in, I'm just trying to make sure that this part is correct. It looks so damn close to the one I just took out.

Anyone replaced a Flexplate and maybe know where they got their part and maybe the model number? Any help would greatly be appreciated and maybe save me like 8 hours of dropping the tranny again.

Trying to get to moab in a week. I would have had plenty of time if this hadn't happened.

Seth

Sounds like the Neutral Safety Switch. Throw it into neutal and try starting it, if it starts thats the issue and it can be taken apart and cleaned pretty easy. If that doesnt work move your shifter nob from park all the way down and up several times and this some times cleans the contacts and also check the plug for it to make sure its connected tight with no wires damaged or anything.

 

[Ecomike]

It is not the NNS, his cranks, he has no spark, that is usually the CPS.

OP, why did you replace the flex plate to begin with? What was wrong with the old one?

Is this a manual trans or AW4 rig?

Aftermarket CPSs have been bad out of the box, mine was!!! I switched brands (Rock Auto, Standard brand made in Italy, not China), most people have gone to the OEM dealer part. And the Renix CPS mounting holes need to be modified (move the CPS closer to the flex plate) to get enough voltage during cranking to the ECU to issue the spark command. And the battery, cables, grounds and starter need to be top notch to get max cranking speed or the ECU will ignore you.

Good sensor grounds are a must, and the spark coil contacts inside the ICM (under the spark coil) may need cleaning and tightening!!!!!

 

[cruiser54]

There were some aftermarket Renix flexplates out there that were indexed improperly. Gave one guy on one of the forums absolute fits. Check the QT one up next to your old one to see if the "windows" line up the same.

BUT, I would be checking CPS output first anyway.

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