TJ won't run after sitting for a long time
- Thread starter Bobsuruncle
- Start date
xxdabroxx
TJ Addict
No, I tried starting fluid to no avail. That’s why I thought it was the PCM or SKIM. Still think it should run on the sparking four cylinders but maybe computer manic won’t let it. Got some throttle body cleaner today so I will add that task to my list. Thanks for the info from everyone. Takes a village.... just don’t like being the idiot. Lol. I will keep you posted.
No luck! I repaired the break in the wire. It was where the harness bends near the valve cover but I saw no indication of chafing. Maybe bad from manufacturer and burned through. Cleaned IAC. Cranks and rumbles a bit more but still no real ignition.
1) how to bypass the ASD relay? 1.8 seconds is not enough time to use a remote starter. If it’s not cranking with key in start, I can’t check spark or injectors. Wife went to work. Needs to keep me in the lifestyle I have become accustomed to!! Ha ha ha...
2) how to check to see if injectors are actually spraying correctly? I pulled the rail, all injectors were dirty but nothing real bad. Tips were clean. Lots of fuel in the rail. A few o rings are cracked so I must replace them. Book says to replace when you reinstall the injectors anyway. I don’t want to drop another $300 for new injectors if I don’t have to. Thanks.
1) how to bypass the ASD relay? 1.8 seconds is not enough time to use a remote starter. If it’s not cranking with key in start, I can’t check spark or injectors. Wife went to work. Needs to keep me in the lifestyle I have become accustomed to!! Ha ha ha...
2) how to check to see if injectors are actually spraying correctly? I pulled the rail, all injectors were dirty but nothing real bad. Tips were clean. Lots of fuel in the rail. A few o rings are cracked so I must replace them. Book says to replace when you reinstall the injectors anyway. I don’t want to drop another $300 for new injectors if I don’t have to. Thanks.
1,2,5,6 injectors are the correct part number called out in the parts manual, 04854181. 3 and 4 injectors (same as the bad coil wire) have 01G051B which all knowing Google says are Ford injectors. Is this an issue? Is the 51B's a replacement used in mods? Thanks.
If you spray carb cleaner / starter fluid in as you were cranking it and saw no affect, then you must be missing a spark. You may have a fuel issue too, but I’d work on the spark first. The PCMs are pretty resilient, so I’m guessing is some broken (or chewed through) wire somewhere.
Thank you. I have confirmed spark. Coil pack was not firing 3 & 4, installed now MOPAR coil pack. Same thing. Found broken wire. Repaired. Still won’t light off. Yes new plugs.
If you have a combustible substance in the intake with spark, but see no effect, then maybe consider very unlikely things like:
- Do the valves work? Could they be frozen open, lifters totally collapsed or busted, timing chain broken, etc.... Pop the valve cover, crank the motor, and see if they are moving.
- Could the CPS installed significantly wrong so the PCM is confused where to send the spark? Don't know if this is possible, just guessing...
Have you tried removing a spark plug,laying it on the block still connected and see if the plugs are actually sparking.This would be a positive test of ignition system.Right now its not clear if it is ignition or fuel.It could be a matter of timing being way off.Just a thought
My plan is to install a new crankshaft position sensor this weekend. Also got 6 refurbished, flow tested Seimens injectors (called for in the parts manual). I will test the coil again, I’ll test the new plugs as well, and I will test the injectors (set in mason jars) for spray pattern. If all are good. I’ll check the Cam position sensor for correct alignment with motor as prescribed in FSM. If it still won’t start I’ll pull timing chain cover to see if it jumped time ( doubtful since I have good compression). Last is PCM.... what a headache!
xxdabroxx
TJ Addict
NO JOY!!! So I have fire at each coil now for sure. Plugs are good. I have injectors spraying a symetric pattern and for sure spraying fuel. I have 47psi fuel pressure, I have compression, I installed a new MOPAR crankshaft position sensor. The cam sensor looks like it is correctly installed according to the FSM. New cam position sensor? Has to be timing of fuel or spark, right? Crankshaft position sensor times spark. Cam sensor times fuel...What am I missing?
Since it was sitting for a long time, could the intake manifold be plugged? Maybe some creature built a nest? Same with the exhaust side. Although I would guess that would have it kinda start, but not run.
Just throwing out wild guesses.....
Just throwing out wild guesses.....
ENGINE START-UP MODE
This is an Open Loop mode. The following actions occur when the starter motor is engaged.
The PCM receives inputs from:
• Battery voltage Good
• Engine coolant temperature sensor Haven't checked
• Crankshaft position sensor New
• Intake manifold air temperature sensor haven't checked
• Manifold absolute pressure (MAP) sensor new
• Throttle position sensor (TPS) really? Haven't checked
• Camshaft position sensor signal haven't changed. position looks good
The PCM monitors the crankshaft position sensor. provides ground to coil to fire plugs
If the PCM does not receive a crankshaft position sensor signal within 3 seconds of cranking the engine, it will shut down the fuel injection system. enough time to fire.
The fuel pump is activated by the PCM through the fuel pump relay. got fuel
Voltage is applied to the fuel injectors with the ASD relay via the PCM. got spray pattern. The PCM will then control the injection sequence and injector pulse width by turning the ground circuit to each individual injector on and off.
The PCM determines the proper ignition timing according to input received from the crankshaft position sensor. ???????
This is an Open Loop mode. The following actions occur when the starter motor is engaged.
The PCM receives inputs from:
• Battery voltage Good
• Engine coolant temperature sensor Haven't checked
• Crankshaft position sensor New
• Intake manifold air temperature sensor haven't checked
• Manifold absolute pressure (MAP) sensor new
• Throttle position sensor (TPS) really? Haven't checked
• Camshaft position sensor signal haven't changed. position looks good
The PCM monitors the crankshaft position sensor. provides ground to coil to fire plugs
If the PCM does not receive a crankshaft position sensor signal within 3 seconds of cranking the engine, it will shut down the fuel injection system. enough time to fire.
The fuel pump is activated by the PCM through the fuel pump relay. got fuel
Voltage is applied to the fuel injectors with the ASD relay via the PCM. got spray pattern. The PCM will then control the injection sequence and injector pulse width by turning the ground circuit to each individual injector on and off.
The PCM determines the proper ignition timing according to input received from the crankshaft position sensor. ???????
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IGNITION SWITCH (KEY-ON) MODE
This is an Open Loop mode. When the fuel system is activated by the ignition switch, the following actions occur:
• The PCM pre-positions the Idle Air Control (IAC) motor.
• The PCM determines atmospheric air pressure from the MAP sensor input todetermine basic fuel strategy.
• The PCM monitors the engine coolant temperature sensor input. The PCM modifies fuel strategy based on this input.
• Intake manifold air temperature sensor input is monitored.
• Throttle position sensor (TPS) is monitored.
• The Up-shift Indicator Lamp is illuminated (manual transmission only).
• The auto shutdown (ASD) relay is energized by the PCM for approximately three seconds.
• The fuel pump is energized through the fuel pump relay by the PCM. The fuel pump will operate for approximately three seconds unless the engine is operating or the starter motor is engaged.
• The O2S sensor heater element is energized via the ASD relay. The O2S sensor input is not used by the PCM to calibrate air-fuel ratio during this mode of operation.
Sorry, I pasted this in and haven’t figured out how to delete it. I guess I’m too tired. These are items I am looking into.
This is an Open Loop mode. When the fuel system is activated by the ignition switch, the following actions occur:
• The PCM pre-positions the Idle Air Control (IAC) motor.
• The PCM determines atmospheric air pressure from the MAP sensor input todetermine basic fuel strategy.
• The PCM monitors the engine coolant temperature sensor input. The PCM modifies fuel strategy based on this input.
• Intake manifold air temperature sensor input is monitored.
• Throttle position sensor (TPS) is monitored.
• The Up-shift Indicator Lamp is illuminated (manual transmission only).
• The auto shutdown (ASD) relay is energized by the PCM for approximately three seconds.
• The fuel pump is energized through the fuel pump relay by the PCM. The fuel pump will operate for approximately three seconds unless the engine is operating or the starter motor is engaged.
• The O2S sensor heater element is energized via the ASD relay. The O2S sensor input is not used by the PCM to calibrate air-fuel ratio during this mode of operation.
Sorry, I pasted this in and haven’t figured out how to delete it. I guess I’m too tired. These are items I am looking into.
New cam position sensor and throttle position sensor installed. Pumped out every drop of fuel the pump could find (jumpered fuel control relay) put in five gallons of ethanol free 89 octane. Nothing! Ready to start cussing