long story short, My jeep won't start. Died while driving. Has new plugs, cap, rotor, wires, coil. New Crank sensor! I've got a fuel pump that seems to be functioning. I've tested the ballast on the drivers fender. Died several times, but it drove home with seemingly normal idle, woke up the next day, drove it till it just stalled for the last time. Where do I look next.

 

Do you have spark? cel? I think cps, even a new one can be bad.

 

What year is the XJ?

 

Faulty alternator? intermittent.....

 

I have strong spark. Turns over strong. Never had to put jumper cables to it yet. And the battery cables look great. Cleaned all my grounds behind the ecm. And....its a 92 sport, auto, 4.0L. has plenty of auxiliary power. I have had alts go bad add the lights fade, radio signal goes to crap, and it leaves you with a dead battery.

 

only thing left is check fuel pressure

 

Fuel, spark, air. If it cranks it's not the nuetral safety switch. If you have spark, it's not the CPS. Next stop: Fuel.

The engine should run (after started) with no battery and/or alternator. But then the battery won't be charged and all your accessories with go bizerk.

 

Check your fuel filter and if its not that check your feul pressure at higher idle and see what happens

 

I have pulled both supply and return, each after making sure the pump has primed the system. Each time there was a small release of fuel when the line clips are released. If it is incorrect fuel pressure, what would be the culprit.


Secondly, I don't know all the symptoms of a backfire. But if you hold the key in an attempt to start, After a few tries, it backfires. Only a single time. IT'S LOUD. Real loud, but I have a VERY non restrictive exhaust, wink. That most likely contributed to the volume of said backfire.

 

And new fuel filter. That was my first assumption. Accessories are functioning normal. It's not electrical. At least not the charging system. I will find a fuel pressure gauge. What is the appropriate pressure?

 

ECM? MAP? IAC? Explain if it can't be one of these.

 

Skimmed over the post so hopefully I didn't miss anything...

If I was in this situation, and successfully tested everything that you have, then I'd start checking all the components you replaced (plugs, wires, etc) and see if any of them went bad at some point after driving on new equipment. You could try individually putting back your old components (if you have them) to see if one of them is the culprit. New parts aren't protected against defect.

 

I have put all this stuff on since it quit working. So if it was a defective new part, it won't change the outcome by putting the same, old part back on. The only part that was on prior to crapping out was an ACCEL performance coil. I dis switch it out with the old oem, but I am getting spark. Also, forgot to mention, a new distributor pick up. But again, I have spark. I am going to go with fuel. I have heard that in most cases, the computer will not continue to pump gas until the engine runs on its own. To prevent flooding a cylinder with fuel. So while I have fuel pressure, something else is preventing the cycle, not allowing it to take over for itself. I still have not checked the system for a specific lb. Of pressure. But I am stumped since I highly doubt this is preventing my from ignition. I mean it used to try to start, or start and run for about 5 seconds, then peter off. Now there is no attempt to combust the mixture of air fuel and spark. Yet the fuel pump still primes the system fully. If it was absent of fuel pressure, the fuel pump would try to prime the fuel rail every time I turn the key.

 

Stilll need to check pressure, I believe it is suppose to be around 40 psi. Thats alot, The pump could still prime the system, but not have enough pressure to spray the injectors.

 

If it is lack of pressure, how would I determine whether it a faulty fp regulator or fuel pump.