Mottobedismit

Yes, I have checked and posted on the other threads, but hoping for more answers. I am having the limp mode issues. My car limps after 4500 in 2-5 gears. It will backfire on occasion. I get a pulsing idle, and when the car is warm I can get that to stop by loading the engine with the clutch untill it almost dies and it will then idle between 800-1000. The car is a 90 vert, with a replacement 89 na motor (not sure of model it came from as it was as is when I purchased it).
My ecu is fried. The .1 resistor and Toshiba MP4501 are badly burned just like the pic shows. I tested the mop on car and it tests OK except for the infinite tests. I do not get a reading with my dmm when trying the infinite tests. Maybe idk how to get a reading there.
I was told that the mop was bad when I bought the car so I got 2 off ebay, 1 tested good, 1 tested bad, so I have a spare mop. I haven't tested the tps as of yet.
I have found the .1 resistor and Toshiba MP4501 online for $10 and I am considering fixing the ecu. Is that a good idea?
Any other possible causes/soultions?
Any help reading infinite ohms?
Thanks in advance!

SpeedOfLife

iTrader: (16)

You said the ECU is fried. I feel I'm stating the obvious, but you should replace the ECU first and make sure everything (like the OMP) seems to be in its place, then see how things go.

jackhild59

iTrader: (7)

I just finished with this same crap, so maybe I can help as I was helped.

Couple of things:

Thing #1
Did you test using the entire test protocol as developed by 1990TurboII-75K and documented in this post?
https://www.rx7club.com/showpost.php...8&postcount=38

If you haven't verified all the tests paying special attention to the tests that involve shorting across two terminals, you don't know for sure that the 'new omp' is good. If it doesn't pass those tests, or if you haven't tested for them, you run the risk of burning another ECU.

BTW, if you are getting no reading, that is infinite ohms


Thing #2:
The TPS is easy to test on the car. Test it and you will find out if it is good or not. Mine was.

Thing #3
I plugged a good OMP into a bad ECU; the ECU did NOT burn out the OMP. I do not think that the ECU has the current output capacity to damage the OMP, especially when the ECU is already damaged.


So, if you want to try to repair your ECU, I don't think you can do any more damage to the OMP, so why not try?

Good Luck, let us know how it turns out.

Jack

EDIT:
Thing #4
If you decide to buy a used ECU, take off the cover BEFORE you plug it in. You know what to look for in a burned ECU. If it is bad when you get it, get your money back. If the seller won't agree to sell you the ECU under those terms, maybe they will be cooperative enough to open the case and send you a picture of the circuit board, front and back, before money exchanges hands.

Mottobedismit

Thanks jack. I did do all the shorting tests using a breadtie to short them. If I do decide to get a used ECU, what part #'s will work in my 90 vert with an unknown 89 na engine? There are quite a few different ecu part #'s. I am assuming they are not all the same.