Grasshoppa

So I bought this 1998 jeep Cherokee sport 4.0 I6 with 157xxx miles. When I test drove it, it ran fine. I bought it then 10 miles down the road it was stuttering bad, and didn't seem to have the gas to go while it was stuttering and then dies while I hit the brakes. I have power so electrical should be fine. The guy I bought it from replaced the battery, spark plugs and wires, distributor cap and rotor, and he said that he replaced the CPS with one from 1A auto. I did a search on here and some said CPS, some said IAC, a fuel pressure check bad cat something like that. So I replaced the IAC, CPS, and did a fuel pressure check. Fuel pressure check was at 49+/- 5 psi while running, cant remember what it was in the on position. I tried kicking the cat to see if it rattled and nothing that. There is a hole in the muffler but I doubt that will make this happen. Takes a minute to start up and if in park on a cold start, I rev to 3k and it stutters/hesitates. Drive down the road stutters and I stop to reverse sometimes dies sometimes I can pull in the driveway and put into reverse and itll die. I use to just test drive with 2 feet but I replaced the CPS and it seems to not die anymore. Now it just revs high in park and neutral and still stutters down the road. Need to know my next move. Oh and the owner did a neutral bypass...something like he stuck a wire in the sensor. That's about all he gave me. Heres the video I tried to take for it. Any feedback is appreciated.

belvedere

Is the Check Engine light on?

Grasshoppa

It is. It was on before and it threw a non sense code. It went away now its back. Havent checked it yet with a scanner. I cant drive it to autozone or something to get it checked anyway..lol

Also, TPS has been changed..no difference revs are anywhere from 1100 to 2500. While in drive and foot on brake it sits at 1100

Grasshoppa

Looks like the PO may have replaced the PCM. Its held up by zip ties not sure if it is or isnt. Also if anyone needs pictures of anything let me know and ill try to post them. Thanks

Grasshoppa

Dont want to be annoying but can anyone help? I need this running soon...

Turbo X_J

Without a scanner to accurately read the codes, you are just shooting blanks.

ETA:
Just be advised PO issues can be a true nightmare.

belvedere

It would really be helpful to know the specific code.


Just a thought: many "high revving" issues are caused by a vacuum leak.

Grasshoppa

Ok ill go rent the code reader again and report back as soon as I get them

Grasshoppa

sorry for the delay fellas, just got back from oriellys. codes are as follows...


EDIT - I searched for the codes on the forum and wrote down what it says for the code here..I think they were the same (or worded a bit different) as what the reader gave us.


p0351 - Coil #1 is not reaching peak current at the right time
p1899 - The Park/Neutral switch seems to be stuck! (the PO said he bypassed this??)
p1391 - Sometimes, I can't see the crank or cam sensor signal
p0505 - The idle speed air control motor doesn't seem to be working correctly.
p0320 - Crankshaft position sensor reference signal cannot be found while the engine is cranking


Anything else helps. thanks

CCKen

What part number is on the side of the PCM?

Grasshoppa

Motorola - 15b3957pppla
chrysler - p56041
module - tem1418pppla

Grasshoppa

if this picture works, its the neutral safety switch bypass or something another

Grasshoppa

Update fellas? Unless I looked in the wrong place I didnt find anything useful about the pcm

Grasshoppa

Anyone else help me? I dont have the money to take this to a shop especially around the holidays and I need it running by the new year for work

CCKen

There should be three more numbers and a set of letters following '56041'.

A '98 with 4.0, auto trans, federal emmisions, the last group of numbers and letters should be 534AB,

"56041 534AB"