General Check engine blinks on-off

Oldsid · Oct 25, 2016

The first time the engine just died while I was driving. It did not want to start right away so I towed the car home. However, it started later that afternoon and was running fine for about two weeks before it just died while driving to work. This time it does not want to start. I checked the fuel pump and it works. I also checked the ignition and there is no spark to all spark plugs. I swapped the power transistor with a spare good one and it still does not start. I have not had the time to properly test the coils and the power transistor but I noticed something weird. When I put the ignition key in the on position, the check engine comes on and off quickly than goes off a bit longer and this cycle itself.
Is this blinking on and off of the check engine means my ECU is dead?

Oldsid · Oct 25, 2016

Anyone has any ideas?

pauleyman · Oct 25, 2016

Oldsid said:
The first time the engine just died while I was driving. It did not want to start right away so I towed the car home. However, it started later that afternoon and was running fine for about two weeks before it just died while driving to work. This time it does not want to start. I checked the fuel pump and it works. I also checked the ignition and there is no spark to all spark plugs. I swapped the power transistor with a spare good one and it still does not start. I have not had the time to properly test the coils and the power transistor but I noticed something weird. When I put the ignition key in the on position, the check engine comes on and off quickly than goes off a bit longer and this cycle itself.
Is this blinking on and off of the check engine means my ECU is dead?

Id say yeah, good chance. At least open it and look for obvious damage.

Oldsid · Oct 25, 2016

pauleyman said:
Id say yeah, good chance. At least open it and look for obvious damage.

I will check it this weekend. I checked it about a year ago it looked fine but since it's socketed, it may be what is causing the problem. Is there a way to check if the socket is good besides a visual inspection?

steve · Oct 25, 2016

Done correctly the socket isn't likely to cause this. Usually it's caused by the capacitors leaking and corroding the circuit traces but maybe you have a cheap socket and now it's making intermitant contact.

Hard to do much but speculate without any data or pictures.

Might not be the ECU, bad battery contacts, MPI relay, Ignition switch, or broken wires could all cause symptoms like this.

mitsubishikid · Oct 25, 2016

While your in the ecu also Inspect your ISC drivers, since a bad ISC is known to sometimes kill the drivers inside the ecu.

Oldsid · Nov 1, 2016

steve said:
Done correctly the socket isn't likely to cause this. Usually it's caused by the capacitors leaking and corroding the circuit traces but maybe you have a cheap socket and now it's making intermitant contact.

Hard to do much but speculate without any data or pictures.

Might not be the ECU, bad battery contacts, MPI relay, Ignition switch, or broken wires could all cause symptoms like this.

My ECU is the problem. A friend had one but it's from a FWD auto. I tried to start and the car starts right away but it run really bad so I did not use it. Is there anything I can do to make it drivable until I can find a good ECU?
It's an Eprom so I am thinking about buying it as a spare and socket it later for use with ECMLink or just use my old TMO chip.
I also opened and checked my ECU and everything look good from the top. When I removed the board, I noticed a lot of "greenish stuff" and that may be shorting the lines. Is it something that can be repaired? Any ideas on how to do it or would it be better to send it to ECMLink to have it repaired?
Thanks a lot for the help.

Oldsid · Nov 4, 2016

Would anyone let me know if the ECU for auto can be made to work on a manual?
I just need to be able to drive the car until I fix my ECU or find a good one.

Doubleot · Nov 4, 2016

Oldsid said:
Would anyone let me know if the ECU for auto can be made to work on a manual?
I just need to be able to drive the car until I fix my ECU or find a good one.

You can use it with no issues.

Oldsid · Nov 4, 2016

Doubleot said:
You can use it with no issues.

I already tried an auto ECU as I explained in my previous posts. It start fine and when it warms up, it runs really bad which really makes it not drivable. I know it will probably run fine if I swap 390 injectors instead of the original 450's, unfortunately I don't have them.

steve · Nov 4, 2016

Oldsid said:
Would anyone let me know if the ECU for auto can be made to work on a manual?

I just need to be able to drive the car until I fix my ECU or find a good one.

steve said:
Hard to do much but speculate without any data or pictures.

I tried searching your profile and a few pages of past posts and couldn't find any specifics about your car other than some clues that it's a 1G manual.

There are differences in fueling, timing, and function between the 1G manual and automatic turbo ECU's but none so different that it would make it undriveable as a daily. I wouldn't beat on but it should make it to the store and back. Remember it's not just the injectors that are different but also the fuel pressure. That makes them much closer in delivered fuel than they seem at first glance.

I hate to be a broken record but without more details it's hard to provide good answers or direction. I can't begin to tell you what's wrong with the existing ECU without pictures.

Doubleot · Nov 4, 2016

Didn't know what year dsm you had I apologize. Please update your profile so we can help you better next time.

Oldsid said:
I already tried an auto ECU as I explained in my previous posts. It start fine and when it warms up, it runs really bad which really makes it not drivable. I know it will probably run fine if I swap 390 injectors instead of the original 450's, unfortunately I don't have them.

Oldsid · Nov 4, 2016

steve said:
I tried searching your profile and a few pages of past posts and couldn't find any specifics about your car other than some clues that it's a 1G manual.

There are differences in fueling, timing, and function between the 1G manual and automatic turbo ECU's but none so different that it would make it undriveable as a daily. I wouldn't beat on but it should make it to the store and back. Remember it's not just the injectors that are different but also the fuel pressure. That makes them much closer in delivered fuel than they seem at first glance.

I hate to be a byeroken record but without more details it's hard to provide good answers or direction. I can't begin to tell you what's wrong with the existing ECU without pictures.

steve said:
I tried searching your profile and a few pages of past posts and couldn't find any specifics about your car other than some clues that it's a 1G manual.

There are differences in fueling, timing, and function between the 1G manual and automatic turbo ECU's but none so different that it would make it undriveable as a daily. I wouldn't beat on but it should make it to the store and back. Remember it's not just the injectors that are different but also the fuel pressure. That makes them much closer in delivered fuel than they seem at first glance.

I hate to be a broken record but without more details it's hard to provide good answers or direction. I can't begin to tell you what's wrong with the existing ECU without pictures.[/QUO

Thanks for the help Steve.
I never checked my profile after the migration to the new website but it is still the same as before the change. I will check it later and update it. I have 1992 AWD manual and I installed an FP exhaust manifold, evo3 turbo, a 3" turbo back EM and an ETS FMIC, a fuel pump rewire.
I know that I can probably drive it with auto ECU. I just found a non-eprom ecu that seems to work. I tested it by just plugging the harness and ground it and the car starts right away and idles ok. When the car was warmed up, the idle speed stabilized around 1100 rpm. I will mounted properly tomorrow and drive a bit to see. Here are some pictures of my ecu to give you an idea about it's condition.

steve · Nov 5, 2016

Oldsid said:
Thanks for the help Steve.
I never checked my profile after the migration to the new website but it is still the same as before the change. I will check it later and update it.

I have 1992 AWD manual and I installed an FP exhaust manifold, evo3 turbo, a 3" turbo back EM and an ETS FMIC, a fuel pump rewire.

I know that I can probably drive it with auto ECU. I just found a non-eprom ecu that seems to work. I tested it by just plugging the harness and ground it and the car starts right away and idles ok. When the car was warmed up, the idle speed stabilized around 1100 rpm. I will mounted properly tomorrow and drive a bit to see.

Here are some pictures of my ecu to give you an idea about it's condition.

Here's what I can tell you from those pictures. You need the capacitors changed and the corrosion damage fixed. I'd send it to Tom and Dave at ECMTuning for rework.

They may have been changed before but what should be clean shiny solder on the bottom is dark. I would inspect the soldering of the socket, they look balled up and inconsistent. Top picture is too small to see anything other than the capacitor by the heatsink looks original.

If the new ECU idles at 1100 RPM you have driven your ISC out of range or it's not working.

Oldsid · Apr 18, 2017

I just had time to check it again and the problem was a bad CAS not my ECU. After changing the CAS, the car runs like a charm except for another problem which I will post a question on the drivetrain section

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General Check engine blinks on-off

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