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mil light gone crazy
Posted: July 14th, 2009, 7:51 am
by daccarettfletez
My swapped in 4.0(obd1 swapped into cj7) used to work fine in the jeep for a good period of time, Recently I stroked it to 4.5 and now it works fine for a while then it just shuts off like if it ran out of fuel(new pump/monitor pressure 40psi with gauge). Immediatly you turn back on and it works again(for 30 min sometimes 5,3,etc). I'm using the grand cherokee(donor) ignition switch mounted on the dash...it has worked fine for years since i did the swap. I hooked up my mil light again(disconnected at the shop when doing the stroker) to diagnose trouble codes(pin 32 blk/pnk tracer other side to + battery post) and it won't throw any codes, but when i turn the engine off/ignition off it will start to light on and off as if it where giving me codes? What could be going on.
Re: mil light gone crazy
Posted: July 14th, 2009, 5:13 pm
by the_wrench116
what year and body donor motor computer? my jeep is a 91XJ and if ya turn it on and off 9 times ending with an on it will flash the codes don't have my hanse manual sorry cant list them.
Re: mil light gone crazy
Posted: July 29th, 2009, 1:43 pm
by daccarettfletez
Mil Light fixed....checked some loose connections(don't now exactly wich ones) and it's working as it should.
Now I have a NEW problem, when I turn ignition to on it won't prime the fuel pump(won't energize it) but if you crank it for about 10 secs it sends signal to the pump and the car starts and works fine...
Diagnose the culprit anyone?
Re: mil light gone crazy
Posted: July 29th, 2009, 2:08 pm
by yuppiexj
It sounds like your fuel pump and/or ASD (automatic shutdown) relay is bad.
I'm guessing you don't hear the fuel pump when you turn the key on before you engage the starter.
snippet from FSM
(key on position)
* The auto shut down (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
one second unless the engine is operating
or the starter motor is engaged
Re: mil light gone crazy
Posted: July 29th, 2009, 5:19 pm
by daccarettfletez
new asd and fuel pump relay...still same problem, I have a fuel pressure monitor connected to the rail, it only receives pressure 10 secs after i'm cranking the engine...if I just turn the ignition on it won't start the pump or hear it work....when it starts it works fine....I'm using the zj oem switch