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Crank Position Sensor MOD ?

JeepBTDT

NAXJA Forum User
Location
USA
I want to do this 'CKPS Mod' and advance the timing 4-5*. I am working on the modified CKPS.

My question is, do I have to move or adjust the CamPS by the same amount to keep them 'in sync'?
 
It's my understanding that the ignition timing is based on the Crank Position timing. Chrysler made 2 CPS, a high altitude model and one for everyone else.
The difference was a few degrees of advance.

Inotherwords... I don't think you need to worry about where the Cam is.

-Ron
 
The answer is no on moving the Cam Position Sensor. It only figures out if it is on the compression.
 
Cut my CKPS and moved it over a little less than 1/2" and epoxied/liquid steel it in place. Replaced it and Jeep starts and runs well. Noticed about 1-2 mpg increase on 1st tankful, will have to keep tracking this and monitor. There was a slight idle and cruise miss that was occuring. Tonight changed out all the ignition pieces and found a stock coil with several cracks and bosch platnum plugs. Changed to Performance Distributors coil, cap, rotor and wires and NGK plugs. Will test later tonight ond over weekend.
 
Cut my CKPS and moved it over a little less than 1/2" and epoxied/liquid steel it in place. Replaced it and Jeep starts and runs well. Noticed about 1-2 mpg increase on 1st tankful, will have to keep tracking this and monitor. There was a slight idle and cruise miss that was occuring. Tonight changed out all the ignition pieces and found a stock coil with several cracks and bosch platnum plugs. Changed to Performance Distributors coil, cap, rotor and wires and NGK plugs. Will test later tonight ond over weekend.

what way did you rotate or slide the cps clock wise ir counter clock wise? trying to wrap my thinking around this.. thanks
 
The upper is a factory high altitude CPS

The lower is modified by some random person who's image i just found. ;)

187713d1366288433t-1990-renix-volvo-bosch-19-280-155-746-injector-swap-cps-advance-comparison.jpg
 
Initially had slight amount of bucking and stumbling, but seemed to have a bit more power/acceleration and 1-2 mpg improvement on 1st tank of gas.

Getting worse, nothing but bucking and stumbling at idle and driving. Threw a CKPS code p1391. Going to put the stock CKPS back on for now.

IDK, it is either the new modified chinese CKPS is bad or going bad or the OBD2 doesn't like this mod.
Someone said that this mod and the high altitude CKPS would only work on Renix and OBD1. Maybe this is true.
Or maybe it won't work with the '98-'99. The 2000+ have COP and no distributor and maybe this is what allows the mod to work.

Maybe I will go to the JY and get an OEM CKPS and mod it and try again, instead of using the cheap ebay chinese junk CKPS.

I even tried to rotate the distributor slightly to change the cam position sensor to help 're-sync' the CKPS and CamPS and one way it ran worse and the other no difference.

I will try again with a mod'ed OEM CKPS and if that doesn't work, might have to have the ECU reprogrammed to be able to add in an additional 4-5* timing advance.
 
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