I have a 94 Cherokee xj. Just rebuilt the motor because I just hit 200,000 miles and it had a lot of blow by and down on power a mpgs. I was pulling 10 on a good day. Put new main and rod bearing in along with new piston rings and fresh gaskets and lapped the valves. Put it back in my Jeep and now it starts hard. When I turn it over it almost stops when hits compression. But with no spark it makes full turn no problem. Plug spark back in almost stops. So I unplugged all my injectors and turns over no problem. So it’s only when it’s trying to fire it hits hard spots at least that the best way I can describe it. If I keep turning it it eventually starts and runs good smells rich but it’s Smooth runs through rpm’s good unless as idle and you give it a “wack” it stumbles. But if you ease into it it’s smooth and had no issue. It does smell rich and have pulled plugs and where black so definitely rich. But good oil pressure and does it at temp and when it’s cold. I went through the usually sensors and nothing seemed to make a difference. No injector’s are stuck confirmed they were working as supposed to. Just to note this has always started right up no problem u till the rebuild the new internal is the only change. I am at a loss any ideas would be appreciated.

 

Are the battery cables in good condition?
Is the check engine light on?
is the timing set correctly?

 

I just put a brand new battery in it and clean the terminals really well with a wire brush as well as all my grounds when I installed the motor. The cables them selves are good no nicks or frays. No check engine light and the timing is correct.

 

Have you checked the starter amp draw and battery voltage while cranking?

 

No I have not but it cranks good and even untill it tries to run. With plugs in but the coil unplugged it’s cranks past compression just fine.

 

sounds like it may be trying to fire at the wrong moment in the compression cycle

dizzy a tiny bit out, did you alter it

plug wires in wrong order ?

I would crank the motor over by hand ratchet, with and without plugs, feel if anything is unusual, its possible some assembly or fit issue is actually causing binding

 

Sounds like you now have a lot more compression which is good, and it’s pointing initially to rule out starter and starting circuit issues.

 

the dizzy is installed wrong I bet.

 

ooh I like that

 

save it!!

 

Yeah if it turns over fine with the coil unplugged I’d look at the distributor also. He did say the timing was correct tho, but he didn’t say if he had the dizzy out.

 

too many unanswered questions at this point. Let's wait for the OP to respond.

 

u could try engine start spray in the snout ?

 

I will try starting fluid down the intake today. I have pulled the dizzy multiple times retiming thinking I messed up but I get the same result each time. The plug wires are in order I have confirmed with the firing order on my intake as well as in the picture. I have heard people getting new dizzy and the locking tab was slightly off so I thought that maybe what’s going on so I shaved one ear off so I can still put it in factory position but can turn it to “advance” the timing. When I did that as soon as I moved it from that factory spot it started loping like it had a big cam and didn’t change the start up.

 

Update: I put a new TPS in and was able to go for a test drive it ran good thought the problem was fixed no more hard start was running smooth and about 3 min into the drive started running like **** popping losing all power trying die and now will hard start and run smooth but give it a rev and starts loping and running like **** again. Turn it off and try to re strat and cranks and cranks trying to start sounds like a 12 valve cold starting so I stop and try again and start right up with one bump of the key but give it a couple revs and goes back to loping and running bad.