caldwell_sean

Ok so I have searched goggle and here and haven't found anything that helps. So here it goes. I have a 94 XJ with 4.0 aw4 that cranks and tries to start but won't this problem started after i changed my oil pan gasket and Accidentally pinched off the O2 wires. Now here's what Iv done so fare replaced the O2, tested the CPS and it was bad some replaced it, checked the fuel psi and it is at 45psi, and checked the spark and it is good, truer resetting the computer. All that and still it well not start it try's but won't. Plz help I'm not good with fuel Infected motors.

Radi

Are your injectors firing? You should be able to hear or feel them clicking. Any fuel on the plugs?

caldwell_sean

Yes they r working. It's like the timing is off or something like that.

Asphalt Cowboy

Just have to ask.
Did you pull the distributor out for any reason?
Did you check the wires going to the coil and distributor?
Did you check ground points?

caldwell_sean

Now I did not pull the distributor. Besides there is no timing adjustment on the distributor anyways so thats not a facter. and yes all the wires r in good shape no melting fraying or anything. Also all the ground points r good.

Radi

I assume you repaired the o2 wiring and checked for blown fuses?
How did you check for spark?

freegdr

Check codes yet it amazing what they can tell ya...

caldwell_sean

Ok so I had to replace the light bulb and checked the codes today and this is what I got. Coolant sensor, TPS, and the intake air temp sensor. Know I need the TPS but and I'm in the middle of fixing the coolant sensor, but what does the intake air one do, besides take the the temp of the air in the intake?

caldwell_sean

Ok now this is really getting old so I changed the tps and still it cranks but does not start. So I started from the beginning. I checked the fire good I checked fuel psi good I checked so instead of checking the injectors by making sure they clack I pulled them outof the intake with them still connected to the rail and checked them to see if there was fuel coming out and got nothing so since I already have 703 injectors I put them in and still nothing. What could it be some one. Plz help!!!!!!!!!!!!!!!!!

caldwell_sean

Yes I replaced the o2 and checked all the fusses and I checked the spark the old fashion way with a screw driver and it has spark because it shocked the **** out of me.

caldwell_sean

Bump

Radi

All that tells you is that there was one spark, lol. Try pulling a plug, connecting the wire to it and laying it on something metal. Crank and watch.
You should have a consistent, blue spark.

caldwell_sean

Mean to b up grateful but I know how to tell if I'm getting spark. My question is other then computer what controls the injectors ?

Radi

Well, there's a crank sensor and a cam sensor. Both feed engine timing info to the PCM, which directly controls both injectors and spark timing.
The injectors have power supplied to them through the ASD relay, the PCM grounds them in turn to actually fire them.
The coil operates in a similar manner, powered from the ASD relay, grounded by the PCM to fire the spark.
If the crank sensor were bad you'd have no spark or inconsistent spark.
The cam sensor I know less about, although it appears to fine-tune the injector timing. That may be an issue if the injectors aren't working right.
Do you have a noid light to check the actual injector pulses?

caldwell_sean

Thank u vary much that is the info I needed. This is the first fuel infected vehicle Iv had this problem with.