ok, so, i just replaced the Crank Position Sensor on my girlfriends 1997 ZJ.

And now its got an incredibly rough idle, i thought it was because of the lack of stock spacer sensor thing... but i put that on and its still the same.

i even reset the ecu..

i posted this on the grand cherokee side, but i have yet to hear from them, and i i figured this would be the place to ask because of the amazing help i have gotten thus far.

what is going on!?!?


--- I just did the off-on-off-on-off-on thing and the Dash showed 12, and 55... i know 55 is end of codes, and i think the 12 is because i cleared the ecu, unless im wrong.. ----

 

Why were you replacing the crank sensor? 12 and 55 are normal/no faults. But flash codes don't give the full picture.

 

I replaced the CPS because i was having intermittent stall problems.

i assumed it was fuel pump. so i replaced it and it continued. i replaced the cps, and now its rough lol... i just boned either way.

 

CPS = Cam Postion Sensor, You said Crank Sensor(CKP) in the first post

4.0 or 5.2

The 5.2 had problems with waivering TPS voltages that would cause unstable idle and stalling problems. Wiggle the TPS with it idling and check for noticable running changes.

Did you replace the fuel filter with the pump? the sliver 'cap' looking thing on top of the fuel pump assy. If you got a complete assy it came on it.

Make sure the vacc hose to the MAP sensor is ok.

Clean the throtle plate. Gummed up deposits will cause idling issues.

Just a few things to check

 

its the 4.0 auto

the fuel assembly is in correctly, and the whole assembly came with the new filter. i will check the map sensor now actually. and i did all the cleaning last week. (iac throttle body ect)


By the way, thank you for your help!

 

And now its throwing "11" code... do you by chance have the codes on hand?

 

 

a scan tool, multimeter, and wiring diagrams would help you fix your problem.

Come on over to VA and I'll help you out!

 

LOL! if it were only that easy haha, im just totally bummed about the problems her DD is now having lol, and i dont dare let her drive mine ahah.

Any ideas?

 

PROBLEM SOLVED!!!!

I had to tap the cps down a little bit. there was no self destruct sticker, so i just had to "earball" it (listen for the clunk of flex plate and then back it up a little bit)

 

Gotta ask. What brand of crank sensor is this? It is not unusual to have aftermarket crank sensors not fit properly. (or work properly). Lots of hit and miss (mostly miss).

Because of that, I always recommend that you purchase crank sensors DIRECTLY from the Jeep dealer.

Well worth the extra $20 for the most critical engine management sensor on the engine. I just ordered one for my 99 from moparpartsonline for $50.49 plus $14 shipping.

 

AWESOME!!

It's good to fix a weird problem

 

$14 to ship it? WOW!

 

89Renix LOL

And yeah i still have a CEL, But it runs like a Kenyan, and starts almost first rotation every time.


Any ideas?

 

Still about $15 cheaper than $75 plus tax which is the cost from the local dealership....