ECU Issues, MAYBE?

[blackmirage]

I've not been on in awhile, but I was having issues with my 90 AWD Talon. The last thing that was suggested was an ECU. Every single part I've purchased has not fixed the issue I am having. So I dont WANT to buy a ECU and have it not fix the issue. Is there any way to TEST the ecu? Because when I looked at the ECU there were no leaking caps or any etching or anything. Board looked great. If there is no way to test the ECU.... There wouldnt be anyone willing to let me borrow one??? I know thats no likely but. Hey its worth a shot.

 

[sniver]

I'd see if you could find someone near you on here and take your ecu and see if it works in their working car or vice versa.

 

[yesItsdsm]

http://vfaq.com/mods/wayback/BradBauer/electrical/code.html

 

[nuclearpenguin]

http://vfaq.com/mods/wayback/BradBauer/electrical/code.html

That's a method for checking the CEL codes, that's no real good for diagnosing an ECU issue.

You've already taken it apart and looked for leaking caps? Did you smell a rotten seafood smell? That's the dead giveaway. My ECU shows no evidence of damage but I can definitely smell it. The only other thing you can try is to borrow an ECU or get a cheap one and try it. I'm stuck in the same boat

 

[yesItsdsm]

That's a method for checking the CEL codes, that's no real good for diagnosing an ECU issue.

You've already taken it apart and looked for leaking caps? Did you smell a rotten seafood smell? That's the dead giveaway. My ECU shows no evidence of damage but I can definitely smell it. The only other thing you can try is to borrow an ECU or get a cheap one and try it. I'm stuck in the same boat

It will let you know however if you ecu is bad.. If the pulse is constant, that signifies there is an ecu problem

*by this method you are not diagnosing the ecu, but rather finding out if it is working properly of not*

 

[nuclearpenguin]

Only if the CEL is on though, also how many people have you heard of tripping the "ECU" code? I didn't even know such a code existed. By the time a device is messed up to the point of triggering that code, I don't trust it to trigger it

To the OP: Do you have a CEL?

 

[sniver]

What was the issue that you were having with it?

 

[93eclipse4g63]

Like people above were suggesting look on www.vfaq.com that site has helped me personally fix a few problems on my DSM that other wise I would have had no idea how to fix. Well good luck!!

 

[blackmirage]

No CEL light. I've looked all over the VFAQ site.. I figured since I wasnt getting a CEL that constant buzzing to let me know ECU not working properly wouldnt work. I will try it though. I bought the car running rough. There was oil in cylinders the spark plug wires were all crossed, leaky hoses boost leaks all that stuff. I've since replaced ALOT of stuff. Coilpack, MAF, Gaskets out the a$$. Its running pig rich, and with the MAF sensor plugged in it WILL not (doesnt like to at ALL) rev past about 3k. With it unplugged it revs and runs better. But DEFINATELY not the way it should be. Still bucks and backfires and whatnot. Its not a pretty site. I'm about ready to take it to the dealership and pay to find out what it is. I just dont want to buy an ECU and have it not be it.

 

[DSM90AWD]

I've not been on in awhile, but I was having issues with my 90 AWD Talon. The last thing that was suggested was an ECU. Every single part I've purchased has not fixed the issue I am having. So I dont WANT to buy a ECU and have it not fix the issue. Is there any way to TEST the ecu? Because when I looked at the ECU there were no leaking caps or any etching or anything. Board looked great.

You either have a very lucky 17yo ECU or the prior owner replaced the caps/ECU already.

Wiseman steve (an ECU expert) diagnosed/fixed my ECU when it took a dump. It's symptoms were random error codes being generated, clicking of the MPI relay and the fuel pump kicking on/off with the engine off and the key in the ACC position. This was my second one, the first one (non-EPROM) had leaking CAPS five years ago that were replaced.

Though as advised above, tracking down a local w/ a 1990 ECU is prol the easiest wasy to take the ECU out of the equation. Can also use a 91-94 ECU but would need to swap pin 6 and 14 on the ECU harness (see the ECU VFAQ for more info

 

[blackmirage]

Well I did the whole CEL thing and the pulses I got were all short. Which means the ECU, SHOULD be ok? It might be possible that the prev person had replaced it, but if not.. Maybe I should just pick a non eprom ecu up from a 90 and see if it works. If it does then COOL. If not, I'll be out of louck on that. Any other suggestion to what could be wrong with the car if the all short pulses means it is a good ecu?

 

[DSM90AWD]

Can you summarize all the things you checked/replaced to date and link back to the original thread(s) that detiled the chronology of your issue?

 

[blackmirage]

http://www.dsmtuners.com/forums/showthread.php?t=240710

There the original post. I replaced the 02 sensor, maf, coilpack, thermostat, gaskets, radiator hoses, plugs, wires. gas ,valve cover gaskets, vaccum lines, fuel injector o-rings.
Fuel Filter, PCV Valve,

Also something I am forgetting. The Fuel Injector Connectors ALL are messed up and look exactly like the pic in the VFAQ for replacing them. I just got them in so I will be replacing the connectors, do you think that this could be the issue? I didnt think so but I'm starting to wonder. In that post I have linked ya to, remember when I say I did something and the car ran GREAT. I mean at idle and that its ran better than before. but In reality its still not running the way it should. My fault, slight miscommunication. Thanks again, any help is appreciated.

 

[blackmirage]

Ok guys I'm going to clean out the TB and also fix these injector plug connector things. However on the VFAQ for cleaning the TB it mentions some things I'm not seeing on my 90 TB so I assume its not for a 90. So my question is where are these two slits I have to cover up or do I have them on a 90 tb?

 

[blackmirage]

Ok Connector Plugs are done, and it does run alot better. At first start up it would rev past 3k but after a ride around the block and running through all gears. It wouldnt. but its not as rough or as bad or as rich as it was. There is still SOMETHING.. Could it be my rubber intake pipe leaking? Causing the hesitations and sputters and the rev issue? or is it not possible for that leaking to cause an issue?

 

[blackmirage]

Could it be the BOV leaking. I'm at a loss at this point. ANY Help would be GREATLY appreciated.

 

[DSM90AWD]

Ok guys I'm going to clean out the TB and also fix these injector plug connector things. However on the VFAQ for cleaning the TB it mentions some things I'm not seeing on my 90 TB so I assume its not for a 90. So my question is where are these two slits I have to cover up or do I have them on a 90 tb?

Yes, the 90TB is different than the 91-94. The main objective to cleaning the TB is to remove the ISC and clean the pintle and it's seat inside the TB so it has complete motion and that passage is not obstructed

 

[DSM90AWD]

Ok Connector Plugs are done, and it does run alot better. At first start up it would rev past 3k but after a ride around the block and running through all gears. It wouldnt. but its not as rough or as bad or as rich as it was. There is still SOMETHING.. Could it be my rubber intake pipe leaking? Causing the hesitations and sputters and the rev issue? or is it not possible for that leaking to cause an issue?

Things that may be at fault:
- Leak between MAF and Turbo (coupler loose/punctured or BOV return not connected)
- Leak between Turbo and TB (Boost leak test to verify)
- Plugs - Platinum/Iridium cannot be used on Turbo DSMs. The electrode is too small and will foul easily. NGK Copper plugs are the only ones to buy (BPR6ES gapped .028 since stock).
- Cam timing = timing belt not correctly installed. Can easily tell by inserting long screwdriver in the #1 plug hole and turning the crank pulley *clockwise* until the screwdriver is at mid dwell at it's highest point. The Cam marks should be aligned at 3 and 9 o-clock AND the cam pulley timing mark should be pointing at TDC on the lower timing cover scale.
- Ignition timing (base timing with ECU grounded should be 5*
- Obstruction in intake pre-turbo blocking airflow - rubber intake collapsing when airflow increases?
- CAS is 180* out
- Fuel filter / Injector(s) clogged
- Bad gas - change stations
- Something is f-ed up with the engine - compression test should tell you general condition.

Give some of these things a try and re-set your ecu to clear any stored codes once you've pulled them to see what they are/were

 

[blackmirage]

It was the ECU, replaced old one with non eprom unit just to find out if it was the ecu, and well IT WAS! It started right up and drives GREAT! Thanks for all the help guys.. I've learned alot just getting this problem fixed. I damn near had the entire motor out.. Appreciate it.

 

[nightspeed87]

My ecu just died last weekend. It had leaking caps that werent replaced in time and for 2 weeks was throwing random cels, and had trouble starting, and now it wont start at all.
Like there is no spark the engine just rotates, so i have another eprom in perfect condition on its way.

 

[yesItsdsm]

Yep, you might remember my car was having a similar problems. Swapped the ecu, battery terminals, ground to the firewall. My car runs so much better and smoother now.