1994 4.0 Cherokee Will Not Start!

[megeneration]

Hello, all! Got a real stumper here: I just got done this weekend rebuilding the engine in my 1994 Jeep Cherokee Laredo, 4.0L, and she will not start. Originally, the head had cracked, so I replaced the head (with a used one that I had machined), cleaned and relapped all the valves, re-ringed the pistons, replaced the rod bearings, replaced the water pump, replaced the timing gear and chain set, gave 'er a tune up, and several miscellaneous other things. Turned her over, and no start. The starter engauges and turns over, the head lights work, I can even get it to sputter and wind up just a bit, like she wants to start, if I hold the throttle pedal to the floor, but still no start. I believe I'm getting fuel (the spark plugs are wet when pulled), I shot a little oil into the cylinders to get a bit more compression and shot some starter fluid into the throttle body: still nothing. So, I thought maybe timing; I set my vibration dampner to 0 degrees, made sure #1 was at TDC, then double checked where my rotor was at in relation to the distributor cap (about the 5 o'clock position, with the trailing edge of the rotor on #1 plug wire), and still nothing! Needless to say, I'm at my wits end. Could someone please give me some pointers, or maybe an idea or two? My head's not working so well anymore, now that I've banged it so many times against the wall! Thanks so much in advance!

[Dale Aeppli]

Originally Posted by megeneration

Hello, all! Got a real stumper here: I just got done this weekend rebuilding the engine in my 1994 Jeep Cherokee Laredo, 4.0L, and she will not start. Originally, the head had cracked, so I replaced the head (with a used one that I had machined), cleaned and relapped all the valves, re-ringed the pistons, replaced the rod bearings, replaced the water pump, replaced the timing gear and chain set, gave 'er a tune up, and several miscellaneous other things. Turned her over, and no start. The starter engauges and turns over, the head lights work, I can even get it to sputter and wind up just a bit, like she wants to start, if I hold the throttle pedal to the floor, but still no start. I believe I'm getting fuel (the spark plugs are wet when pulled), I shot a little oil into the cylinders to get a bit more compression and shot some starter fluid into the throttle body: still nothing. So, I thought maybe timing; I set my vibration dampner to 0 degrees, made sure #1 was at TDC, then double checked where my rotor was at in relation to the distributor cap (about the 5 o'clock position, with the trailing edge of the rotor on #1 plug wire), and still nothing! Needless to say, I'm at my wits end. Could someone please give me some pointers, or maybe an idea or two? My head's not working so well anymore, now that I've banged it so many times against the wall! Thanks so much in advance!

PULL THE WIRE OUT OF THE DISTRIBUTOR CAP AND CHECK FOR SPARK. ITS POSSIBLE THAT YOU UNPLUGGED THE CRANKSHAFT SENSOR. IF YOU MAIL ME I CAN SEND INFORMATION, TO HELP CAN'T SEND THRU FORUM [email protected] Dale

[blacky horse]

check the crankshaft sensore or check the fuel pump relay but i think its the crankshaft sensore.

[megeneration]

Thanks for the replies; I checked the fuel pump relay previously, and it's ok; not sure why the crankshaft sensor would go T.U., but I think I may have figured it out... I pressurized my cylinders with compressed air, and on cylinders #2-5, I'm getting a significant amount of blow by from the intake valves; just to be double-sure, I removed the rockers so the valves should have been completely closed, and they still did not seat. So.... I guess I'm pulling the head.... AGAIN! Appears to be a compression problem. Thanks for all the help....

[nancilr]

My brand new... okay remanufacured 4.0 Ltr, I6 for my 1993 Cherokee Sport is doing the same thing as this. The Reman. company is Recon Engine rebuilders, purchased through an Advance Auto Parts store (major chain). I have replaced the CPS, distributor, full tune-up, checked every circuit I can thing of, have fuel, compression, spark, even replaced the coil. The computer (ECM/PCM) I even put in another '93 Cherokee and it worked fine in that Cherokee, started right up. I've not tried the compression leak-down test.
The only thing I have not checked is if the manufacturer installed the camshaft wrong, putting it out of time some how.... I did have to remove the head after installing the engine because the remanufacturer (Recon Engines out of Pittsburg, Pa) some how managed to let the engine leave the factory with a broken off Temp. sensor in the Temp Sensor port of the Head.... what a dissapointment.
Finally, I just pulled some fuel out of the tank to check for water in the fuel... Nope! THere wasn't any.
I have nothing left to try except to pull everything off the front of the block until I can get the timing chain cover off and check to see if the cam was installed wrong.
I really hope some one has run into this and can help with some info.

[Dale Aeppli]

Originally Posted by nancilr

My brand new... okay remanufacured 4.0 Ltr, I6 for my 1993 Cherokee Sport is doing the same thing as this. The Reman. company is Recon Engine rebuilders, purchased through an Advance Auto Parts store (major chain). I have replaced the CPS, distributor, full tune-up, checked every circuit I can thing of, have fuel, compression, spark, even replaced the coil. The computer (ECM/PCM) I even put in another '93 Cherokee and it worked fine in that Cherokee, started right up. I've not tried the compression leak-down test.
The only thing I have not checked is if the manufacturer installed the camshaft wrong, putting it out of time some how.... I did have to remove the head after installing the engine because the remanufacturer (Recon Engines out of Pittsburg, Pa) some how managed to let the engine leave the factory with a broken off Temp. sensor in the Temp Sensor port of the Head.... what a dissapointment.
Finally, I just pulled some fuel out of the tank to check for water in the fuel... Nope! THere wasn't any.
I have nothing left to try except to pull everything off the front of the block until I can get the timing chain cover off and check to see if the cam was installed wrong.
I really hope some one has run into this and can help with some info.

ARE YOU SURE THE DISTRIBUTOR IS IN TIME, DID YOU CHECK FOR SPARK AT PLUGS AND DISTRIBUTOR DALE
GIVE ME A HOLLER I'LL SEND SHEET YOU CAN CHECK DISTRIBUTOR
[email protected]

[nancilr]

Yes, I checked for SPARK at each plug and I have it. The distributor I put in with the #1 piston at TDC on the compression stroke, the harmonic at "0" advance and the rotor pointing at the #1 plug wire at the cap. I replaced the distributor (new) to be sure the camshaft position sensor was good and I did have to replace the Crank Position Sensor (CPS) because I HAD no spark, but when I replaced the CPS and tried it, I had spark. What do you think? I'm out of ideas... real bad.
Someone help!?!

[Dale Aeppli]

Originally Posted by nancilr

Yes, I checked for SPARK at each plug and I have it. The distributor I put in with the #1 piston at TDC on the compression stroke, the harmonic at "0" advance and the rotor pointing at the #1 plug wire at the cap. I replaced the distributor (new) to be sure the camshaft position sensor was good and I did have to replace the Crank Position Sensor (CPS) because I HAD no spark, but when I replaced the CPS and tried it, I had spark. What do you think? I'm out of ideas... real bad.
Someone help!?!

did you say the temperature switch was broken off it controls the fuel and spark thru computer [email protected]

[megeneration]

Are you sure, Dale? I broke my temperature sensor off of the head about two years ago, and she ran fine up until about 4 months ago... nancilr, I would check my compression, if I were you... you say you pulled the head (for whatever reason), did you replace the head gasket?

[Bondo Don]

As I mentioned to "PatriotJeep1", I will bet big money your distributor is off by one tooth. I did this exact same rebuild, positioned the distributor the same way you did (just like we do for the 60s and 70s engines) and it wouldn't start. Finally took it to a dealer who moved the distributor by one tooth and it started fine. Take out the hold-down bolt and crank the engine while turning the distrubitor, probably to the retard side. If it starts, shut it down and carefully reposition the distributor. Good luck.

Donnie