CPS and Column Shifter

[Dandxj]

- 1990 MJ AW4 with column shifter

- 4 Liter

 

I am replacing the CPS on the truck. It will crank but not run. The CPS ohms out at 250 ohms but the cranking AC voltage is

only .25-.30 volts. I have replaced the CPS on my XJ before but it has a floor shifter. Looking under the truck it looks like I would

have more access if I removed the shifter cable. Has anyone done it that way before and did it help ?

Now for the big question. Where to get a reliable CPS. When I did the XJ I got it from the dealer. That was around 10 years ago. It was pricey back then - around $65, but worth it ( still working fine ). The dealer no longer carries the CPS and says new MOPAR CPS is not available.

Advance/Autozone/Oreillys carry them but I question their quality. NAPA lists three CPSs - all essentially the same price but with different warranties. An Echlin with 36 mos, a Proformer with 12 mos and a Dorman with a lifetime warranty. I usually avoid Dorman electrical stuff unless absolutely necessary. I had a Wells in the XJ when the OEM went out but it did not last long - less than two years. That is why I went with MOPAR.  Any comments and suggestions for a replacement would be appreciated.

[eaglescout526]

The dealer is lying to you or at least the parts guy is and probably doesn’t want to get a vintage part for you. There’s still some CPS’s out there at the same price you paid 10 years ago. 

[Dandxj]

How do I go about persuading the parts guy to try harder? I'll also try a different dealer.

Thanks

[eaglescout526]

Ask them if there’s any out there as NOS. The parts counter guys fears are that you’ll want to warranty it when it fails and most don’t want to go through that trouble. As long as you make it known to them you are aware of the issues in getting an older mopar part and you express explicit interest in getting mopar, they will do it. Or I will since I enjoy helping the us get parts. 

[cruiser54]

Have you tried drilling out one mounting hole to bring the CPS you currently have closer to the flexplate? 

[Dandxj]

I have not drilled the current CPS. I was going to do that when I got a new one. When I replaced the one in theXJ I drilled it out before installing. Has worked great for years. I guess I could try it on the current CPS - it would not cost anything. It is just a major pain to get

one in or out of the truck. 

[cruiser54]

4WD? Disconnect the front driveshaft at the transfer case to get more room.

[Dandxj]

Thank you for the advice. I removed the front driveshaft. Access is still tricky, but much more room. ( The real problem is I am getting too old to be laying on my back under the truck ).  I drilled the CPS and reinstalled. The voltage went up to .52 volts and it starts quicker.

Not too bad for a 32 year old sensor. Hopefully I can end my hunt for another OEM CPS. Would there be any advantage in enlarging the lower hole as well ?

 Thanks again

[cruiser54]

.5 is great. More wouldn't hurt I guess.