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Post by justyjohn on Sept 1, 2005 21:54:37 GMT -5
i just came into this 93 justy and havenot had any time to do any diagnostics myself but this is the story i was told: the car had some problem that the repair garage thought could be fixed with a new head which was then installed. that done, the car was started but while it was running a coolant leak was detected at the left front corner of the engine as seen from the driver seat. engine was shut off, the leak attended to but the engine would not restart. diagnosis by the repair garage was that the ECM had gone bad. the car has also had a coil replaced at same time. i think that short
of some idiot mistake like wrong polarity on battery jump start or failing to ground all static electricity from body and tools prior to handling components that the ECM computer was fairly bulletproof. i intend to proceed troubleshooting myself in this order: compression test, test for spark, check timing, check fuel delivery. any one got a different idea? curious where others might begin to test . i know that so far symptoms and the description is not that detailed. more later. CUL and thanx.
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Post by justyjohn on Sept 22, 2005 19:13:56 GMT -5
follow up to the post of 09/01/05. additionally, someone replaced the fuel pump relay which so far as i know now is working at least on the primary side but the fuel pump is not working . Also, there is no spark and the check engine light does not come on. i cannot yet tell if the injectors are firing over the noise of the engine cranking. The fuel guage is working. who thinks what?
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Post by SUBIEJIM on Sept 22, 2005 22:30:05 GMT -5
Sounds like it could be a couple of things. You say that the fuel pump is not working. Question: Is the pump pressurizing the system at all ? Typically, when you turn the key to the ON position you should hear the pump come on, pressurize the fuel lines and than go off after 2 sec if the engine is not cranked (Safety Feature)..... Then, when you turn the key to the START position the engine cranks over and the ignition switch then energizes the starter solenoid, the ignition system, and the fuel pump based on a signal sent from the distributor (Crank Signal) to the ECM (Engine Computer) this signal is also used by the ECM to pulse the injectors on and off. If you have fuel pressure in the lines but, no spark and no injector pulses while the engine is cranking it is usually either the distributor or the ignition switch. My guess is the ignition switch. (This is the round part under the dash attached to the key cylinder that is mounted on the column. The switch has a connector on the back side and is attached to the key cyl with 2 small screws). I have replaced this part on 4 Justys (3 carbureted cars and 1 fuel injected car) they go bad quite often. The distributor may also be the problem but, I'm still saying Ignition Switch based on what I have seen. Couple of other things: If you don't hear the pump run, pull out the lower portion of the back seat, remove the round access cover to the fuel pump assembly and check the power lead with a 12V test light. (Should light up when key is turned on and when the engine is cranking.) Check for fuel pressure at the rubber inlet line going into fuel rail ( located under the hood, coming through the firewall near passenger side). Good Luck!! Jim
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Post by justyjohn on Oct 5, 2005 22:53:44 GMT -5
thanx jim for ur suggestions. checked ignition sw assy and all is fine there. have been running the underhood engine wiring harness as was evident someone had been messin' inthere and found a wire withall the plastic melted off and several others in the same place with overheating signs. since i get no check engine light ever, i intend to swap harness and computer from a bent 94 that i have already. with the condition of the wiring, i am guessing the distributor is ok. ? other views? thanx.
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