88 GW dies when it gets hot

[Ristow]

don't matter. put it together and run it. if you look at the slot,you can usually see scratch marks from the roll pin.

[FSJ Guy]

Eeh...my bad, I just read that again and I came off a Lil harsh. Didn't seem like that in my head when I typed it.

No worries, Cory!

I would just try to retime the engine the old fashioned way by turning the engine to TDC and dropping in the distributor and lining it up.

[aerocorey]

Cam sensors on the newer Jeep 2.5, 4.0, 5.2, 5.9, and probably a few others were inside the distributor, under the rotor, and read the on-off pules from a one-bladed reluctor ring to tell the ECM when to fire which spark plug and fuel injector.

FSJ's have a sensor in the same place on an 8-bladed reluctor ring to tell the (primitive) ECM when to fire which spark plug. It serves a very similar purpose.

The difference is the distributor on newer engines is locked into place, so the distributor position correlates directly to camshaft position, hence why the sensor in the distributor is called the camshaft position sensor. On our FSJ engines, the distributor can be rotated independently of the camshaft, so the distributor sensor has no correlation to camshaft position. It is merely a distributor position sensor, pickup coil, trigger coil, whatever you want to call it.

Sigh...really? You're gonna tell me that it's a completely different sensor from one engine to another based on whether or not the distributer body is capable of being rotated? Ok, dude, you got me. I have no idea what I'm talking about. You should probably talk to me like I'm stupid and pick apart the totally legit advice I gave to OP which was immediately followed by someone else giving the same advice.

I guess this is what IFSJA turned into while I was overseas for a few years. Y'all have a nice day.

[Carnuck]

Incorrect taxonomy aside, it sort of works the same way. With EFI cam sensor housings are generally stationary (with either a rotating signal generator or a hall effect sensor that reads a tone ring) and most are non-adjustable as they tell the computer excatly when the motor is at TDC and how far it is from TDC intake stroke to control fuel injection.

The Jeep ignition pickup is a hall effect sensor that sends pulses to a transistorized ignition box to control spark only and not differentiate between which cylinder. The ignition rotor controls what cylinder gets the spark at the cap. The pickup coil just tells the ignition when to make a pulse and it doesn't know or care which cylinder. In that way it's more like a crank position sensor.

[mgmann]

This is drving me nuts!

This is driving me crazy! I?ve replaced distributors many times, and never had this kind of problem. Set timing mark to TDC, rotor pointing to #1 wire, position of the distributor is identical to what it always was but all I can get is a back fire. I move the distributor a few degrees one way or the other and it still doesn?t work.

I?m on the verge of just going out and buying a new distributor but first I?ll see if anyone can give me some hint as to what might be going on.

Thanks again??..

[Carnuck]

This is driving me crazy! I’ve replaced distributors many times, and never had this kind of problem. Set timing mark to TDC, rotor pointing to #1 wire, position of the distributor is identical to what it always was but all I can get is a back fire. I move the distributor a few degrees one way or the other and it still doesn’t work.

I’m on the verge of just going out and buying a new distributor but first I’ll see if anyone can give me some hint as to what might be going on.

Thanks again……..

You are 180 degrees out of time. Pull the dist and turn the rotor directly away from where it is now and it should fire right up. You are currently firing as the air/fuel mix is going in.

[FSJ Guy]

This is driving me crazy! I?ve replaced distributors many times, and never had this kind of problem. Set timing mark to TDC, rotor pointing to #1 wire, position of the distributor is identical to what it always was but all I can get is a back fire. I move the distributor a few degrees one way or the other and it still doesn?t work.

I?m on the verge of just going out and buying a new distributor but first I?ll see if anyone can give me some hint as to what might be going on.

Thanks again??..

X2 on it being out of sync 180 degrees.

Here's how to correct it:

With everything as is (distributor being installed 180 degrees out, engine backfire, etc):

Disconnect the battery
Turn the crank so that the timing mark on the balancer reads "TDC" and the distributor is pointing at the #1 plug.

THIS position is actually 180 degrees out of sync. NOW, turn the crank ONE REVOLUTION to "TDC" again.

VERY IMPORTANT: ONLY TURN IT ONCE!!!!

Now you will observe that the distributor is NOT pointing to the #1 plug at all. This is good. (at the moment.)

Next, PULL the distributor out and re-insert it so that it is pointing at the #1 plug.

Snug the distributor hold-down bolt a bit, but not too tight that you can't turn the distributor a little bit. (for timing it later).

Re-connect the battery. Hook up your timing light. Fire it up and time it as you would normally (engine at operating temp, distributor advance removed and vacuum line plugged).

Don't worry. I've had this happen to me, too, and I had to have someone remind me that there are two "top dead centers".

[mgmann]

Hanging my head in shame......

Yup, I was so rattled that I didn't bother to check if #1 was on the compression stroke. Obviously it wasn't. Got the beast running and timed. Had it idling for half an hour with ac on and so far it's still going. Sure hope this is the end of this hassle. If so I learned a lot. If not......back to the drawing board.

[4x4Dad]

This board has some very helpful chaps, and threads like this remind me of how great a community this is to be a part of.

[FSJ Guy]

Excellent news!

[mgmann]

Thanks for everything

Got the beast back up and running. Took it for a long drive today with no problems. Guess the sensor in the distributor was the problem all along. I am now a much wiser dude. Thanks for everything guys.

[bull4377]

I'm just stoked to see another Montanan on here