so far on my 1990 3.0 4x4 mighty max, ive replaced the coil, ign control module, ecu elay and the sensor inside the dizzy, and have had the ecu rebuilt twice the thing just sits and turns over but wont start its still not getting spark either. so what should i do next. look into getting the ecu checked out again, and if thats not thr problem look into replacing the engine wire harness. help is much needed and i am very thankful for any help or ideas you have.
Last edited by camoit; 11-25-2011 at 12:32 PM.
Sounds like u have a break in a wire or stretched or did you check ur fusible links and all ur fuses?
Do you have a manual that tells you what plugs and what pins in the plug should have power?
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if you are getting gas and no spark i would say fuse, bad wire....maybe a ground missing. There are a fuseable links as stated above... just get a tester and check everything. load tester or whatever tool it is....good luck man....
The mpi relay also supplies power to the coil and injectors. Have you checked for voltages at the relay?
troubleshooting can be a real pain in the a$$...i would just go through and check everything for power coming and going....do it with the key off, the key on accessory, then the key in starting postiion, while cranking, etc...unless you know more of where your problem isOriginally Posted by 4doorciv
good luck to you...
its not getting spark or fuel. my brother checked the plugs at the ecu and said everything that should have power does. the fuel pump wasnt turning on at one point. after i changed the ecu relay it started working normally. ive checked the fusible links and the originals were dryed out and cracking. i got some decent looking ones from a wrecked low mileage montero at the junkyard. and i also found the main ground wire was unhooked from the block. i put it back. also the parts i replaced in the first post came off a running parts car.
You should tell him to test the wires at the relay. The fuel pump can prime with the starter signal but still not give power to the coil and injectors. That should be actuated by the key on position I believe. Ground is controled by the ecu. Check for power.
ok. ill try that this weekend. i can do that with a test light. if its a good relay that would mean the somethings up ith the wiring from the relay to the coil and injectors right? cause my fuel pumps primes, but it didnt before. and its normal for the fuel pump to only work when its turning over right. it doesnt prime when i turn it to ignition. also reading around on some troubleshooting info it said there was a TDC sensor. would this make it not spark or deliver fuel?
Last edited by joey_crandall; 04-14-2011 at 10:47 AM.
The fuel pump should prime while engine cranking and should stay on while the car is running. It doesn't prime when you put the key to the on position like other manufactures.
The tdc sensor, I'm sure is part of the distributor. I could be wrong but I'm pretty sure. I have been wrong before.
ok so the crank position sensor (mitsu calls it a photo optic sensing unit) is the tdc sensor. i appreciate you taking time to give me ideas and helping out the best you can.
atleast you are narrowing it down slowly. I hope we can help you get it running man. Good luck bro.
I don't mind helping out. I'm tossing ideas out, can be helping others out with the same problem. I'm back to working on my truck so a lot of it is coming back to me. So your helping me at the same time.
i hope it runs soon to ive had the thingsince the middle of september. thisi weekend if the weathers nice im gonna get my brother to help me try to figure more out.
sweet man ....keep us updated ....
so i took a test light to it earlier. with the light hooked to -side of coil and + side of battery it comes on with the key off. same way with +side of coil to- side of battery. but it doesnt come on either way with the key at any other position. acc, on or when when its turning over. any ideas?
So what your saying is that there is power to both sides of the coil in the on position and accessory? Or no power at all?
no theres power to both sides when the key is off.
Power to both sides when the key is off. What about when the key is on? Is there power to one side? Or no power at all?
nope the coil doesnt have power with the key at acc, on, or start. only with the key off. someone on sqc said it sounds like ign swith and to jump the starter solenoid if it starts i got my answer. and i tried a jumper wire to the coil from the battery like someone had suggested at sqc, and all my dash ligths came on with the key off.
Okay. With that info, I agree that it sounds like your ignition or wires to the ignition. All this info your finding out is helping narrow it down. Keep it going man. Your almost there.
someone over at sqc said it seems like the ignition switch is out. any way i can hot wire it?
have you took the plastics off the column and tested all of them...there is a little mechanism in there that transfers power in and out. It has wires that come in and split off for the diff key settings on the ignition tumbler. Its for the accessories, ignition, and fuel related for signal....It can go bad, burn out in a certain area etc ..it is a main power spot in the ignition system...
good luck man....almost got it..
i used the oen from my starion today. the original switch was melted at the harness connector. ade the male connector on the chassis harness was also melted. i have some pics.
sorry for the crappy cell pics. but its the best i got.
in this pic you can see part of the male connector from the chassis harness in the upper left corner.
this is the chassis harness from the bottom
and this is the chassis harness from the front
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