Need help with getting this bitch going...

[Stomis]

Well I officially have a reason not to like jeeps now. And yes I'm still doing this f'ing head gasket. It has fought me and fought me between the injectors wires getting mixed up, plugs getting fouled, vacuum being a mess and the damn freezing weather. Ok so I'm done complaining.

1989 4.0 Cherokee

I finally got a wiring diagram so the injectors are in the right sequence. The vacuum is all together and the plugs are cleaned up. Now I'm pretty sure what is the knock sensor that broke when I tried to unplug the connector is keeping it from starting... The sensor that broke is under the manifolds and is on the same harness as the o2, injectors, and other FI sensors.

So will a disconnected knock sensor stop a 4.0 from starting? If not then where the hell do I go from here? Everything went back together exactly as it came apart, I'm gettin pissed.

 

[Greg72]

Looking for sympathy about a Jeep on a Chevy site???.....


A 350SBC will proabably fit. Somebody out there probably already has a kit developed for it.

 

[Mr. Pickle]

Have you tried NAXJA? They are great over there and would probably answer your question in no time at all. Good luck!

 

[supersize75k5]

you should have the renix system for that year , is it on the drivers side, low on the block, near the engine mount?

have you checked for spark and fuel pressure on the fuel rail? Make sure the distributor is clocked correctly, and make sure the wires are on in the right order: 1-5-3-6-2-4 iirc


edit ...bark up this tree too

--------------------------------------------------------------


SYMPTOM/CONDITION

Some 1989 vehicles equipped with the 4.0L engine and automatic transmission may experience an engine no-start, hard restart, or an engine die-out. This condition may be caused by low signal strength from the crank position sensor due to a larger than desired distance to the flywheel sensing ring.

DIAGNOSIS







Check to see if the vehicle has a slotted crank position sensor:

1. If the vehicle is equipped with a slotted crank position sensor (see Figure 1), check to see if the CPS grommet on the top of the transmission bell housing has been updated (see Figure 2). If the CPS grommet has not been updated, replace the CPS grommet per the Repair Procedure outlined below.


If the vehicle has a slotted crank position sensor and new CPS grommet, do not install a new sensor, but reinstall the slotted sensor that was on the vehicle and verify that it is good using procedures in the 1989 Jeep Service Manual 81-370-9045 on page 14-87.

2. If the vehicle does not have a slotted crank position sensor already installed, then proceed with the Repair Procedure.


PARTS REQUIRED

1 Crank Position Sensor (slotted) PN 83100067
1 Crank Position Sensor Grommet (dust cover) PN 83100068

REPAIR PROCEDURE

1. Turn the ignition switch to the "OFF" position.

2. Disconnect the Crank Position Sensor (CPS) from the engine harness.

3. Raise the vehicle using a lift.

4. Remove the old CPS and grommet.

5. Install the new CPS grommet.

NOTE :THE NEW CPS GROMMET MUST BE REPLACED SO THAT THE MAXIMUM SIGNAL OUTPUT CAN BE OBTAINED FROM THE NEW CRANK POSITION SENSOR.

6. Install the new Crank Position Sensor and loosely attach the retaining bolts.

7. Firmly press down on the slotted hole side of the CPS until it bottoms on the machined lip of the bellhousing. While holding the CPS down against the bellhousing, tighten the bolt on the slotted side of the CPS to 16 ft.lbs.

8. Tighten the remaining attaching bolt to 16 ft.lbs.

NOTE :MAKE CERTAIN THAT THE CRANK POSITION SENSOR IS COMPLETELY BOTTOMED ON THE MACHINED LIP OF THE BELLHOUSING AND IS AS CLOSE AS POSSIBLE TO THE FLYWHEEL SENSING RING WITHOUT CONTACTING IT.

9. Secure the lead of the CPS to the retaining clip on the bellhousing to prevent its contact with the exhaust manifold.

10. Lower the vehicle.

11. Connect the CPS to the engine harness.


POLICY: Reimbursable within the provisions of the warranty.

TIME ALLOWANCE:
Labor Operation No. 08-15-79-90 0.3 Hrs.

FAILURE CODE: 0X - Wrong Part

 

[Stomis]

See I've read through all this. I just dont get how it could be running fine and I put everything back together properly and now it wont start. The only thing that isnt back in place like it was is the knock sensor.

 

[supersize75k5]

hmm

start with the basics, pull a spark plug wire and check it for spark,..it that checks out, then put a fuel pressure gage on the shrader valve and test your fuel pressure


you know the sensor is busted though, might as well replace it

 

[toomany]

I know it sounds stupid...but did you tighten down the rockers to much and the valves aren't fully closing. Unless the 4.0 doesn't have an adjustable valvetrain, I've never had to dig into mine. I also know that era of Jeep had problems with the wire harness comming out of the firewall. It gets knocked loose and only lets a few things work.