I own a 1993 Jeep Xk 2 door 4.o liter with an AW-4 transmission. I recently purchased this truck and new it had a rear main seal leak. Well I wanted to clean the engine bay up to trace any other leaks and weaping fluids. Along comes the powerwasher and degreaser. I did not leave the engine running while I did this...

well the engine started but ran like total crap with a choking out of idle if I gave any throttle.... not good.

The next day the motor cranks over but will NOT fire.

I went into complete tune up mode.

I replaced the distributer cap, rotor, wire, and plugs, removed and cleaned the throttle body.. IAC valve caked with grease.

Jeep still cranks but will not fire... (even with dumping raw fuel into the throttle body). So I start with the sensors... as of TODAY I have replaced the Idle Air Control, the TPS, and the Crank Position Sensor. I have verified that I have SPARK at the coil and SPARK at the plugs.. dumped some raw fuel into the throttle body.... Jeep STILL refuses to fire up. I have checked all fuses ,,,, verified that the fuel pump spools up and works...

At this point I am completly frustrated by not being able to figure this out and I'm about done throwing monet at sensors and misc parts to not succeed.......

Can anyone advise what could possibly be going on with my XJ.

Thanks again.. and great forum

Jeff

 

i know its gonna sound silly, but have you checked all your fuses and relays? its a good place to start.

 

Yes I did a visual on all the under hood fuses ... relays well I'll trust they are OK.. The fuel pump kicks on for the 2 seconds they un powers because the XJ doesn't fire..... .... Weird that I get spark at the plugs but it will not fire ever with raw fuel into the throttle body ..

Oh I pulled the codes.. got a 33 and the ending 55 ..

 

not to sure on the 93, but on my 97 there is fuses inside the jeep under the passenger side kick panel...

code 33...i think thats A/C clutch relay circuit... id see if you can get a wiring diagram to check if there is anything else on that circuit that gets its power from there (ie the ecu). i dont know if there is anything tho... i don't have a diagram for that year. was that code present before all your headaches?

 

Honestly never checked.....

 

Just went out to garage and repulled.. I don't get the 33 anymore.. But now a 12...

 

ever thought of it being ur ecm computer...if its bad it would crank all day but never start.. i dont believe it likes direct water.. although they seem to be sealed pretty decent.. might check it out.

 

the 12 is :

12 Battery or computer recently disconnected

which makes sence since I swapped batteries out a couple of hours ago..

So with a 12 and a 55..... I am not throwing any codes... But the XJ still will not fire.....

 

Yea.. thought about that... but with fuel and spark you would think it would attempt to fire...

 

Well, you have spark.

Engines need three things, fuel, compression, and spark at the right time. If the engine isn't starting with a splash of fuel in the throttle body, well, then you are either missing compression or the spark isn't occuring at the right time. Have you checked the timing on the distributor?

 

Like I said... it fired before I got it wet.... I only changed the cap and rotor on the Dist... I never messed with the timing on the distributor.

I just pulled the plug on the ECM and used compressed air to clean the male and female portions ....Have not tried to fire it..

Is there any way to "test" the ECM module ?

 

This may not be helpful ... but ... have you tried just resetting the computer? Sounds as if you were doing fine until you power washed then started right in on tune up ... etc. I'm not positive with your model but ya might get lucky just by disconnecting the battery for a few minutes. I've been wrong before though ...

 

What the Hell.... I'm up for anything here... Just pulled the battery,,, I'll hook it up tomorrow after work

 

What do you guys think about the cam position sensor.

 

Cleaned some connections and put the battery on the charger last night. Gonna go another round with thr xj tonight