I bought a 1990 Mitsubishi Eclipse GS-T. I was told that the ecu was bad. The car would not crank up when i bought it. I got another ecu and replaced the old one. Both ecus had the same numbers on front of them. I then cranked the car. Seemed like it was fixed. I noticed that the car was stumbling like it was not firing on all cylinders. We checked and sure enough it was only firing on #1 and #4. I then bought a new ignition coil. After we installed it we tried to crank and it would not start. So we checked for spark again. This time I had fire on #2 and #3, but no spark on #1 or #4. I am confused. This is my first DSM so and help would be great. Car is completly stock. I also removed the ignition control module, and i am waiting to see what yall say before I go drop another 100 bucks on something I might not need.

Thanks......

 

Plug wires??? Not too familiar with a 4g63... question prolly better asked on dsmtuners.

 

where did you get the new eCU?

 

Aight heres the deal. I just purchased a reman. ecu today from Advance Auto parts, rather pricy. I replaced the entire coil pac(both coils included). I am having same problem, The #1 and #4 cylinders are firing both at the coil and at the end of the plug wires. #2 and #3 cylinders have no fire at the coil pac, so the wires are a non issue. Has anyone ever heard of anything like this before. The car will crank and run, but as you might expect, a turbo charged car dosent run very good on 2 cylinders. I heard something about the cam angle sensor. Could that fix this problem? Please help I'm going to go broke before I ever get a chance to drive this car.


Thanks..............

 

just found out that my motor is from a 1994 eclipse gst. Would that make a diffrence in which ecu I would have to use. The parts place says they take a diffrent ecu so what do yall think.

 

souldnt to my knowlage have you though it may ingnition mod itself possable pcm? the best suggestion that i beleve can be made is the problem seams to be to advanced for basic dignostic tools if i were u id go spend the 80 bucks for a dealer to tell you what it is or point u in the right direction insteam of throwing parts at the car.

 

Is your check engine light on? A cam sensor will USUALLY cause a sporatic miss, not necessarily 1&4 or 2&3, not saying its not possible. Definately sounds like an ignition problem though, the ones ive done that had that problem was either the ICM, the coil, but mainly the PCM (ECU, BRAIN, WHATEVER). the computer problem was RAMPANT in the 1st gen eclipses so if you got your new puter from a junk yard the chances are you got another busted one. good luck!

 

do not get confused the "pcm" and the "ecu" are two differant items.

 

All right I think I can at least shed SOME light on this subject (Now that I'm back again LOL). It shouldn't be a PCM problem if anything it'll be an ECU problem. If you have a reman ECU from a retail joint then that shouldn't be the problem (There WAS a KNOWN capacitor leak problem in the ECUs of them). The 90-94 ECU's are all the same. A bad cam sensor would more than likely cause a sporatic miss in random cylinders not in the same cylinders all the time. The fact that you've seen instances on both 1&4 and 2&3 not firing indicates there has to be a common item that's starting to go... Unfortunately I'm looking through my book here and not really seeing anything. I'll keep reading and see if I can find something. Hopefully the other things I posted here help a little to eliminate a good chunk of the guesswork you've been doing.

 

I have had fire on 1&4 and no fire to 2&3. I have also had fire on 2&3 and no fire on 1&4. If that makes any sense. I have replaced everything to do with the ignition system. Everything I put on the car was new, nothing used. I have 1&4 firing again so the car will crank up and run now, just runs like crap. I know that in the 94 4g63 the cam and crank sensors are not in the same place like the 90-93 4g63s are. My motor is said to be from a 94 gs-t. They used all electronics from old motor(1990 4g63). Could my problem be that my motors crank sensor is in the bottom end of the engine, and not hooked up. I think that the cam sensor sends info to the ecu to tell when to fire, and so does the crank sensor. what im asking is will my 90 cam/crank position sensor work properly or should I use a cam sensor and a crank sensor from a 94 4g63. I know this sounds complicated, but thats what I got going on.

Thanks....................