4.0 starting problems

I just had a new 4.0 put in my 2001 limited. We also put a new battery, alternator, waterpump, plugs in it. When we try to start it, it turns over fine but won't start. The ASD relay (auto shut down) buzzes when the key is in the on postiion. When we add a Jump to it from another vechicle, it starts and runs fine but that is the only way it will start.

We checked the battery and it is putting out 12.48 volts so there is nothing wrong with it.

Could it be the Crank Position Sensor?:repair:

Hallo. If it runs after a jump, it is not the CPS.
Mayby the starterrelay or Ignition switch or fuses . NSS can also gives a problem. But the starter will crank? So this line is OK.
So at least switch the ASD relay.

Hallo again. Are you sure about the good condition of the battery and its cables and connectors?

Check the ground on the left hand side of the engine. Make sure its tight, if its loose it will do that.

I talked with my mechanic today and he said he tried a new CPS and it didn't make any difference. I know that the battery is good, and we have switched with another one, (2 new batteries). He said while it was running, you could see on the amp gauge that the battery was discharging. We installed a new alternator when we switched engines. I'm going to print my responces so far and see if he has tried all of those. Thanks for your help so far.

Check the NSS i had the same exact problem with mine try putting it in neutral and then starting it......

xJeepxXJxThingx said:

Check the NSS i had the same exact problem with mine try putting it in neutral and then starting it......

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He said it turns over fine. That right there says its not an NSS problem.

I took all of the responses that I got here and went to see my mechanic. He said he had checked all of the grounds and it was still baffling him! When we went outside to start it, it turned over and fired but do to the cold Michigan day it didn't stay running. The next start it just turned over. I shut the key off and tried it again and it started. Every time it didn't start, the ASD Relay hummed loudly. I drove it about 2 miles and shut it off. When we started it up I had to go through the key on/ key off about 4 times before it started.

Could it be the ground on the fuel pump and if so, where is it, or something else.

I'm taking all suggestions because I don't want to get stuck out in the middle of the Northern Michigan woods with a dead Cherokee

Did you change the humming ASD relay?

Yes we changed the ASD relay with another cherokee and that one started fine with either one so we ruled out that.