xjbeachbum990

Hello, I have a 97 4.0 cherokee I've had for about 3 months now.
I took it about 45 mins out of town and blew my head gasket (the motor ended up shutting off on me) immediately after it was running real rough at idle, especially under the load of being in gear. I had to drive it back home like this before it finally stopped firing on me.
Replaced head gasket (making sure the head wasn't warped or cracked) and got it back together.
After replacing the gasket the motor wouldn't start unless I held the gas down and would only remain running as long as I gave it throttle.
When it ran like this it wouldn't go past 45 without the whole motor shaking and it kind of felt like the rear end was under a lot of stress after this speed (everything before and up to except heavy acceleration drove smooth).
I replaced the distributor in it as wwell as the cam sensor to see if it would smooth it out and it has not ran since.
I've replaced so far my plugs, wires, rotor, cap, and cleaned my iac valve along with replacing my tps.
Any ideas or leads to what I could check next would be greatly appreciated..

Thinking maybe it skipped time somewhere due to the lack of running in high rpm?

Firestorm500

When you had the head off, did you check the cylinder walls for galling?

Did you turn the engine by hand to make sure there was no dragging or stiffness in the reciprocating components?

If it got hot and/or stayed hot, you might have cooked the lower end.

xjbeachbum990

Cylinder walls are good, crank spins smooth. Since this incident I've had it running and driving, for the most part aside from the previously mentioned rough running in the higher power band and rough idle.

firehawk618

Let me understand this.

You blew the head gasket 45 minutes away from home and only discovered this because it got so hot that the engine essentially lost compression / seized up until it could cool down and run again.

Then you *I assume* added water and drove it home 45 minutes again?

What I am getting at is just how bad the engine got cooked.

Typically when a person runs and engine until it gets so hot that it will not run anymore the damage has been done. No amount of sensors, gaskets, fluids are going to restore it.

xjbeachbum990

Yes, I did add water and drove it home. I had to stop twice along the way because my temp light would come on. Also when it overheated I knew it was because of said temp light but had no where to pull over (I was on the highway at the time) and by the time I had a place to stop the engine shut off on me.
As you said if it is internal im aware there isn't much I can do shy of rebuilding the bottom end. With that being said I posted on here to get more ideas of what's going on here. I figured somehow my bottom end played a part in it but I wanted to find out more from people who knew more than I do.

firehawk618

Compression check should tell the story.

'90Cherokee

If compression checks out it's something not done right. Sensor connection or intake leak is my first guess.

Radi

If it hasn't run since you did those two things, go backwards one at a time and put the old parts back.

Are you smelling fuel? Might have cooked one or more injectors. They shut off when you press the accelerator to the floor which might explain why you have to do that to start it.