A month ago I bought a 94 XJ Country 4.0 with a blown motor, but it came with a (supposedly) known good motor. It hasnt run in almost a year.

Last weekend I finally buttoned up the engine replacement and got her started. I had to borrow my brothers battery as the XJ did not have one when I brought it home. And I had to manually force the starter relay to close in order to engage the starter, but I got that figured out last night.

In the process of replacing the motor, I also upgraded to the newer style intake manifold and 4 hole injectors from KSuspension, Brown Dog motor mounts, Stinky Fab trans mount, and a full tune up which consisted of Champion copper plugs, new distributor cap and rotor, air filter, and 195* thermostat..

So as expected, it took a bit of cranking to prime the fuel system and it finally came to life. At first, it ran like crap (presumably as the PCM relearned whatever it had to). Eventually the idle settled to around 800rpm's and throttle was pretty responsive. It had a tad bit of hesitation, but it revved up just fine. Once I got it started and up to operating temperature, I shut her down and took the battery out to put back in my brothers TJ. Well, I presume it was operating temperature because the top radiator got hot when the thermostat opened. The gauge never moved. It stayed 1/2 way between 190 and the first line.

I let it sit for two days, and last night I installed a battery and I figured out the ignition wiring. So now it cranks by the key. But the first time I cranked it, it again took about 5 seconds of cranking before it started and it sputtered to life.

So here are my questions.....

Was it hard to start because each time the PCM had to relearn parameters?

Is it also possible that a defective coolant temp sensor would cause hard starting because it is giving the wrong temp signal to the PCM? ( I bought a new temp sensor today and will be replacing it).

Is there anything else I should be looking at?

 

I would recommend following cruiser54's tips first and get those grounds cleaned up first. You can find the link for his tips here somewhere. Let us know how it goes.

Edit: Here is a link for cleaning the grounds:. http://www.naxja.org/forum/showpost....28&postcount=6

 

After you clean those grounds up, put a fuel psi gauge on it. Sounds like the fuel pump / check valve could also be on the way out.

 

Did you drain the old gas before starting it?

 

A little update....

Turbo, To answer your question, The tank was nearly empty (gauge BARELY moved off E) when I got it. So it has 6 gallons of fresh gas.

I can't attest that the grounds are GREAT, but they are good. It cranks over just fine with no hesitation. I will be upgrading the battery cables anyways because the sheathing is pulling off the wire at the terminal end. And when I do, I will wire wheel & De-Ox all connections.

And a little discovery...

So last night I tried to start it again just to do some more searching. and after having sat for 2 days with a battery hooked up the whole time, it was still a bear to start. I hooked up a fuel pressure gauge to the rail and Key ON Engine OFF it popped up to 32 psi. Engine running with the FPR vacuum line hooked up, it was getting 37 psi. Engine running with the FPR vacuum line disconnected, it pops up to 44 psi. After shutting the engine down, it holds pressure for atleast 10 minutes with no bleed off. So I believe my fuel system is good.

I did discover one pretty major vacuum leak. The MAP sensor line is broken completely off. So its not even hooked up. I will fix that tonight and will try again.

I also believe my evap canister isn't hooked up right. The small line at the top of the purge valve goes to the intake manifold (like I believe it should). The big line goes to the air cleaner assembly (also like I believe it should). However..... The fuel tank vent line I cant seem to locate. Where I believe it is supposed to hook up to the evap canister, that nipple is blocked off. It almost looks like a vacuum cap was shoved in the hole. This could cause a problem when I go to get it smogged.

Also, I think I am hearing a major vacuum leak in the two evap lines that are present somewhere along their route along the firewall. Those lines are hidden behind the main wiring harness. So that could cause a big problem as well.

 

Fix the map and hose. without that you got nothing. amazing it even runs at all with no map.