Zakua

Not exactly the way I wanted to come into a jeep forum! I have been admiring lots of rigs on this site for sometime...anyways...

My 94 XJ had a bad flex plate. It wasnt cracked but the TC bolt up holes on the flex plate side had been warbled/oblonged out so at certain RPMs you get some banging noises. Once the trany was dropped out we noticed that 2 of the bolts connecting the TC and FP where backed out 2 or 3 threads...LOL...matter of time eh??

So I got a OEM replacement FlexPlate matching the year and double checked the timing windows and obviously the bolt pattern...it's keyed so there is only one way to get it on anyways =) bolted it all back up. Plugged in the three sensor harness connects and the CPS connect...now it wont turn over. Starters turnin it and it wants to kinda run for 15 seconds or so but sounds like the timings waaaaay off.

Oh BTW the CPS sensor is new..had to replace that last winter...

phew, loong post lol

Any ideas?


This is my 3rd Jeep cherokee, I bought it new in 95, its on procomp 33s with a procomp 4inch lift (getting a little saggy after 10 years tho lol)..maybe if I get it running again I can post some pics of the prudy now retired to street queen beast! I got a 06 TJ on 35s for playing with now.

IT'S AN XJ THING

Just because the sensor was new you could have still damaged it. There's only a few things that cause crank no starts. 1. fuel (lack of) 2. lack of spark (no spark mainly caused by crank and cam pos. sensor failure) I would start by checking the sensor to be sure. just don't throw parts at it though. If possible, have any codes pulled to get a starting point. here's the procedure

IT'S AN XJ THING

Crankshaft Position Sensor Connector


NOTE: To perform a complete test of the Crankshaft Position (CKP) sensor and it's circuitry, refer to the appropriate Powertrain Diagnostic Chart. To test the sensor only, refer to the following:

PROCEDURE

1. Near the rear of intake manifold, disconnect sensor pigtail harness connector from main wiring harness.
2. Place an ohmmeter across terminals B and C (SEE Image). Ohmmeter should be set to 1K-to-1OK scale for this test. The meter reading should be open (infinite resistance). Replace sensor if a low resistance is indicated.

IT'S AN XJ THING

Sorry about the image, don't know why it did that. It was of the sensor connector. My bad, if you need it let me know

Zakua

Thanks man.

We got the thing on a scanner and the CPS reads fine sooo we are leaning towards the gap between the timing holes and the end of the CPS....when I had replaced the CPS last winter, I remember putting it on carefuly...but this last weekend after doing the flex plate replacement I used an air rachet to throw the CPS on lol...I'm betting it may have kicked it up or over on one end or something like that, making the gap to big or just flat out crooked.

I still have the old CPS if I need to cross check for broken parts as the old CPS works...most of the time...haha

Thanks for the replies!

fantic238

did you compare the two plates before mounting it?

Zakua

Hello Fantic.

Yes we did compare the plates..short of getting a micrometer/caliper out, they matched up. Timing windows in same positions and the keyed crankshaft bolt holes match (I wouldn't of been able to get it on if they didn't).

Wishing I wasnt at work so I could go loosen the CPS/CKP and hand position it and try starting it...Im betting it'll start up but I am crossing my fingures lol.

Zakua

Well not much room to "move" that CPS sensor around...we loosened it up and re tightended to varied degrees to get a start and nothing . lol

Friend of mines a lead Mech at a Chrysler Dodge and he called in to specify the Flex plate was correct and all that checks out. Im heading up in a few with an Ohm meter to check the CPS, I hope its DEAD so I can just buy a new one (or Napa may warranty this one since its not even a year old) and get it running again!!

Good times under the hood, hahaaa!
Thanks guys for the input! I'll keep you posted

Oh BTW we checked fuel, good and checked spark, good...sensors last thing in the loop...

mopwrd340

i just installed a new flex plate in my 93 and havent put the trans back in yet . as you said it only bolts one way to the crank but when i compared them the windows were off from the way it was when i pulled it off the crank but looking at it i figured there are 3 sets of 4 windows on it and it shouldnt have made a difference?? mine was made by omix

fantic238

You have both fuel and spark and it doesn't start?
Did you mess with the distributor?

Zakua

SHe takes some cranking to get it started but wont stay running for 15 seconds. It has never ever had a problem running since the day I bought it new in 95 (well aside a dead battery incident). The only other troubles it had was when the original CPS went out.

THe distributor is keyed, yes the mechanic (my chrysler mech friend) pulled it off briefly after we were having problems getting it to run but thats all back together now and we moved on to fuel witch checked out....
So I put the ohm meter on the pins to the cps this morning (didnt get off work until 930 last night) Not really sure what way to position the cps to ensure A,B,C pins but there are only two possibilities since there are only 3 pins...I ohm'd both ways and both times the reading came back with a low resistance.

Mopwrd, my new FP is Omix aswell. verified with them twice that it is the correct OEM replacement AND my friend called "Specify" department of dodge chrysler and yes it was correct part for replacement so we should be in good shape bro.

fantic238

The distributor housing is keyed but not the shaft. Once you pull the distributor it needs to be indexed.

Zakua

Ooops sorry Fantic, no the distro was not removed bro =) OMW to napa in a few to get a CPS.....*crosses fingures* heh heh

mopwrd340

okay thanks had me wondering for a minute

Zakua

Allright, final update...Its alive! haha put the new CPS in and she started right up. Did the drive around as it relearned idle and what not, now it runs like a top.

Thanks for all the help guys!