94 grand cherokee, dying

[zchrisz]

hi people, 94 grand cherokee 5.2l v8, when it idles and i hit the gas to about 2k rpms and let off the throttle the tack will fall right down and the truck will die, start it up, it'll be fine, rev it the same way and it will die, but i just noticed if i rev it up to 3k or more and let off the same way the tach will come right back down to normal and be fine? any thoughts? i just changed out the distributor cap, gonna do the wires soon, it has 120k on it

 

[XJNick]

Hi,

Check (or have checked) your:

> Throttle Position Sensor (TPS)
> Idle Air Control Motor (IAC Motor)
> Crankshaft Position Sensor (CPS)

as either of them could be causing your problem. Also you might clean the Throttle body and IAC passageways with some carb cleaner, as Carbon build up in the TB can cause erratic idleing.

-Nick :!:

 

[zchrisz]

High Output Alternator?

i havent checked that stuff yet, where is the crankshaft position sensor located? also would these things throw an ecm code? i have no codes just 12 and 55

 

[XJNick]

CJ Build Project Pics

Hi,

The CPS will be bolted to the Transmission Bellhousing, most likely one the driver's side. If it is mounted like they are on the Cherokees, it is pretty hard to get to.

To answer your second question: Don't count on it. All though newer ('95+) OBD-II diagnostic systems are pretty accurate at determining faulty sensors, the older OBD-I systems (which your Jeep has) aren't neccesarily going to indicate a sensor is bad, especially if it is acting erratic and is only messing up sometimes.

Although, it could also be a dirty Throttle Body causing problems.
-Nick :!: