Hey guys, I've been lurking for a while as a new member and even before without membership but have recently acquired a Jeep! I have been wrenching on my newly acquired 1997 TJ 4.0 manual for some time now as I had quite a bit to fix. I have however, run into an issue I would really appreciate some help with.
As of yesterday, I have a no start issue on the Jeep.
It cranks over very healthy but won't start. It briefly had an issue where it would stall out at idle a few times or after throttle input and it would take a few tries to start. The issue has now turned into a no start. (This may be unrelated but when this was happening I got the common low oil pressure check gauges dash light telling me I had very low oil pressure (around 1-5psi). I did however hook up an oil pressure gauge and found that my pressure is not a problem.)
Onto the problem. As stated it cranks without a problem. I recently installed new plugs gapped to .035, spark plug wires, and the IAC. At first, I cleaned the original IAC with carburator cleaner and thought it my have been the problem for my rough idle/ stall issue and led to the no-start issue but cleaning didn't fix it so I installed a new one. Still nothing.
I have checked for spark which I am getting. the spark plug wires all arc'ed to the valve cover when turning over the motor.
I have attempted to put fuel in the throttle body and start it that way without success (I didn't have a friend to help so I poured a little fuel into the intake with an open throttle plate, allowed the plate to spring closed then poured a little more on top and feathered the pedal while trying to start it.)
As it looks like I am getting spark I'm confused as to why the fuel through TB didn't work - maybe I didn't put enough in or not a a constant rate?
Tomorrow I will be headed to pickup a fuel pressure gauge. I will find out if I have full fuel pressure at the rail.
I DO hear the fuel pump whine at startup.
I have pulled several codes off of the jeep.
I got 12 - for the battery wire to the PCM being disconnected - upon checking the terminal was loose and it was fixed.
Then code 17 for the car not reaching operating temperature within limits. This happened before the car progressed from stalling out to NO-start.
I also got Code 21 (twice) for the o2 sensors.
Then the NO-Start issue occurred
The IAC was cleaned/replaced
These codes where then cleared via a disconnect of the battery.
Then the next codes- 12 again, 25 for a fault in the IAC? 27 (three times) for
"Injector #3, and/or 4, and/or 5, and/or 6 output driver does not respond properly to the control signal." Then 42 for an ASD issue or fuel pump relay issue.
AS it stands after clearing the codes again I only have 12 and 25 that remain.
The relays all seem good. The ASD relay and fuel pump relay were switched with the known good relay from the horn. I am getting spark so I don't believe it is a crank position sensor? I believe the issue may be in the PCM, since I figure so many seemingly random codes popping up may point to it. I will know about fuel pressure at the rail tomorrow and report back.
I appreciate your help in advance guys, thanks a lot!