ecu problems

[twonhiroshima]

so here is the deal.....have an eagle talon 2.0 16g awd slight modified. 93 btw sat for 2 years and I replaced the trans will crank but not catch. Did that before I replaced the trans. Did some investigating and the issue is that the mfi relay is not kickin off. Bout the shrmatics from mitchell and basically I disagree. It seems to me my ecu powers the mfi which powers the ecu ....that doesn't make any sense. Does anyone know how the 107 and 102 pins get their juice? Thanks guys....this is a hard one I am sure.

 

[WORPeclipse]

Im having the same prob with my honda. Its doing the same thing. Has been narrowed down to the ecu.

 

[luv2rallye]

http://www.dsmtuners.com/forums/new...k-engine-light-need-help-troubleshooting.html

 

[91Bomb]

I've had a bad ecu make the MPI relay click on + off repeatedy and had semi-bad ecu's cause all kinds of problems. Did you open up ecu and check for any signs of cap leakage?

 

[steve]

No CEL during the first five seconds after you turn the car on indicates that the ECU isn't powering up.

First have you checked the MPI fuse on the positive battery terminal?

Check to make sure you get 12v at pin 103 on the ECU. It comes from the room fuse #19 next to your left foot.

The ECU has to get 12v at pin 110 from the ignition switch when you turn it to run. In response it will pull pin 63 low to turn on the MPI relay. The MPI relay then applies 12v to ECU pins 102 and 107 and the ECU if it's working correctly will boot up turn the CEL on while the rest of the dash lights go through bulb check and then turn off.

 

[swapped92talon]

You should invest into ecmlink...then you would have access to answers for any ecu question. LoL...but for the not so lucky, you will just have to wait for an electrical wiseman to help on here. But what you are saying does sound right to me from what I remember with the ECU. Good luck!

 

[steve]

you will just have to wait for an electrical wiseman to help on here.

!

 

[twonhiroshima]

I appeciate everyones help. I suppose the ecu is bad. Anyone know where I can get another? Everywhere I looked has given me te runaround.

 

[91Bomb]

Classifieds here or other dsm forums, local dsm boards, craigslist, ebay etc. If buying on ebay try to get one with a no questions asked refund policy. On my local CL board there's always several guys parting out dsm's. Average good used ecu's are around $75 plus/minus 25 bux.

There are dsm members that professionally recap eu's for cheap and if your board isn't damaged but cap(s) look suspect then replace them. The new caps will last a long time and probably a lot longer than the original subpar caps from the factory.

If you do buy a good used ecu the cap replacement is always a good idea too since these ecu's did came with caps prone to leaking.

Also good to have a spare ecu around for the next time you're trying to hunt down mysterious problems you can do a quick swap to either confirm or rule out ecu PLUS for any 100+ mi road trip it's a good idea imo to carry a spare ecu among other things.

 

[twonhiroshima]

Thanks man. I was also curious....my car is a california with the special egr valve. how important is it to get another california model ECU? if it is important i guess i will be getting my rebuilt.