Earlier this spring I got sick enough of the alarm that I grounded a purple (with a stripe) wire. It worked just fine. The ZJ also had a bad battery, so I replaced that. After replacing the battery (including cleaning it and the cables), perhaps a few days after replacement, the jeep would crank and start and run for a few moments and then die.
I replaced the spark plugs, wires, and distributor cap. I replaced the ignition coil. Now the starter will turn it but the engine doesn't run. I started testing the fuel system--there is pressure at the rail, enough for gas to spray out of the schrader valve on the rail, but the pressure tests were inconclusive (I can't seem to borrow a working fuel pressure tester anywhere.)
I replaced the fuel filter and added some fuel injector cleaner--no luck.
I had the entire distributor, which I assume included the camshaft position sensor, in 2005...which I realize is almost ten years ago, but still feels new heh.
I'm wondering if I should continue trying to get an accurate fuel test, or start replacing the camshaft position sensor or replace the crankshaft position sensor?
(I have someone who'd like to use this vehicle...so, I'm trying again. Also, no blinking error codes to read from the dash.)
I tested the ASD relay and no luck. Played with the computer connectors and recleaned the battery terminals and connectors. It is a new battery and voltage reads fine. I'll test the crank position sensor.
It will start turning but it doesn't actually start the engine--just cranks.
Edit: I've seen to replace the computer, crank position sensor, and camshaft position sensor...just trying to find the next logical thing to throw at it for this no-start situation.
Might sound dumb, but have you checked the PCM/ASD amp fuse under the hood? If it's popped....check your wiring to your o2 sensor at the cat...it's a known culprit for shorting and popping that fuse....which will create a no spark situation.
Before you pay for anything you need to get some throttle body cleaner or mopar combustion chamber cleaner (its awesome) and really clean the throttle body until its spotless (especially the port where the iac attaches). make sure you either clean the iac really good or replace it. If it will start after you rev the engine while cranking, its most likely an idle air problem. I think i pretty much had the same problem you are having now. if that doesn't work, get back to us. Before you start replacing sensors you need to get a voltometer and test the battery for a parasitic draw or any blown fuses. then test the sensors to see if they are actually bad. if that doesn't lead you somewhere, replace the capacitors in the computer. if your battery is old, replace it. a bad battery or one that's close to bad could definitely cause this problem. check for any vacuum leaks that may mess with things.
does it start when you give it gas while cranking? if it does then you can probably get it to start idling if you hold the revs up to about 1-2k for a minute or two and slowly let off the gas til it can hold itself. if that's whats happening i think the idle air isn't opening the throttle up enough and keeping it there enough to idle good or the computer isn't sending it the right voltage to keep it going. at least thats what I narrowed my jeep down to, its been doing this for a while and i finally got it taken care of I think (i just recleaned the iac port, cuz i didn't do it last time i cleaned the tb and now it starts alot stronger, but the problem was intermittent so idk) I ended up replacing alot of parts that didn't solve the problem so some logical testing and troubleshooting will save you alot of money in this case if there's one thing I learned.
good luck, maybe with a little more info i can help you more
edit: just read you replaced your battery so disregard that, but i bet you that its not the crankshaft sensor if you got a spark
Get a code reader and pull the codes, too. But I warn you that many times the codes are WRONG if the PCM is getting bad data from some sensor or it's actually acting up. At least it might point you in the right direction.
I am assuming you've combed through Zeejay's list of 12 items to check? Don't go buying sensors yet but if you DO have to buy any, get MOPAR sensors, especially the crank sensor. Jeeps hate aftermarket sensors for the most part. They also hate weak batteries and bad ground connections....so check ALL the grounding points.
And just for grins....use your key to lock and unlock the rear hatch....'might get lucky.