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Both ASD and fuel pump relays switch on when key is turned, and 2 seconds later power off. Then while cranking they do not turn back on. I measured with a meter. I am not familiar with the Mopar PCM and what it has to see for it to send power to the coil and fuel pump. I was looking at scanners, that way I think I could test the sensors without taking them out. The crankshaft position sensor wiring is on top of the trans and it's nearly impossible to get to to try and test.
I was looking at getting a OTC 4000e scanner with Pathfinder2 1993 card but does anyone know if that would truly give me access to test all the sensors and help me diagnose what's wrong?
I appreciate the advice. Thanks!
If the asd relay is not powering the coil,02's and injectors it's not going to start regardless of what condition the sensors are in. It seems your problems are stemming from the pcm. Do you know the # that was on the original pcm?
The PCM will trigger the asd/fuel pump relays for a few seconds at initial key on, after that, it needs to see the engine turning to trip 'em again. Generally, that's the crank position sensor, though theoretically, the cam sensor will do it as well, though, I have never seen that. Verify you are getting five (eight?) volts to the crank sensor with ignition on.
so you still have no spark even tho the asd relay is still activating? if so i would be checking voltage at the coil. i would also be checking the ground signal to the coil to see what it is doing. if there is no pulsing of the ground i would check wire continuity between the computer connector and coil connector. if the wire is fine and still not getting a pulse the issue is likely in the computer. i am not as familiar with a 93's computer but on my 89 the switching transistor is responsible for firing the coil. https://www.theprojectasylum.com/ele...dakotaecm.html
The pcm in the truck is 5602 6868. I re capped when it wouldn't start it and still didn't help. Ordered a rebuilt PCM # 5602 6866 (which is the same but not California emissions). It still wouldn't start. Replaced the crank sensor with the Mopar sensor and it started and ran with the rebuilt pcm. It died twice with that pcm, so I switched back to the original and it ran great. Then it died again, I had it towed and it hasn't started since.
I did order a OTC 4000e scanner so hopefully I will be able to which sensors are working or not.
When I get it I will post what happened and the results.
The crank sensor plug is on top of the transmission and is near impossible to unplug, much less get a meter on- hopefully the scanner can tell me what's happening with the sensor
I did order a OTC 4000e scanner so hopefully I will be able to which sensors are working or not.
i haven't actually tried mine with my 93 but the info available on a 91 and 89 is pretty impressive. i only got the 79-92 cartridge. it also allows you to do a bunch of stuff like cycling the relays or solenoids individually. you can also access a bunch of live data and see what the computer sees.
Okay, I got the OTC 4000e scanner, hooked it up and tested some stuff. Still haven't found why it won't start. I'm not sure about what all the abbreviations are bt I'm really not sure it has a test for the crank sensor. I added an additional ground strap from the battery just to rule out the possibility of a bad ground. when i try to do an ignition test it just keeps cycling and seems to never end. I really have never used this tool but a lot of it is straight forward, but I really don't know how long the duration of each test is. If anyone who is reading this knows about these code readers and can tell me that would help. Here is a list of what the scanner tested, the red is a fully charged 12.6 battery.
Yes, during the test I am getting spark at the coil with a spark tester inline.
Cranking it over though, no spark. I can't find anything wrong with the wiring either.
This is way more baffling than my previous truck- a 69 D200. That was pretty easy to troubleshoot, this one way more challenging.
I appreciate all the suggestions.
The scanner is really cool but I seriously think it is missing a way to testy the crank sensor
