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So your capacitors have certainly been replaced already, along with some resistors. It also appears whoever did it soldered them from the top of the board of some unknown reason. I mean the ECU is a through hole design so just a tiny little bit of solder from the back side is all that is needed, not the mountain of solder on there now.

As for the "corrosion" it's hard to tell. It could possibly be flux that was never cleaned up from when the caps were replaced.
 

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Discussion Starter #3
Okay this is great info! Im not sure if theyve been replaced though...I had to rip the warranty stickers on the metal casing.
 

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Also.......damage, both corrosive and electrical, from leaking capacitors.......can cause component failures elsewhere on the main and supplemental vertical boards.

It's no easy task to find ALL the failures, for a given situation.

Hope this helps.

Kevin
 

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1991 Dodge Stealth ES 5sp
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You can carefully go over any parts that look dirty/corroded with a cotton swab and some rubbing alcohol. I was able to get my ECU working a bit better after doing some light cleaning while I wait for a new ECU.

Examine the pins for any buildup between them. If they are gunked together, used very fine tweezers/a tool to pick out the gunk carefully.
 

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Discussion Starter #6
Also.......damage, both corrosive and electrical, from leaking capacitors.......can cause component failures elsewhere on the main and supplemental vertical boards.

It's no easy task to find ALL the failures, for a given situation.

Hope this helps.

Kevin
This does help, thank you!
 

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Discussion Starter #7
You can carefully go over any parts that look dirty/corroded with a cotton swab and some rubbing alcohol. I was able to get my ECU working a bit better after doing some light cleaning while I wait for a new ECU.

Examine the pins for any buildup between them. If they are gunked together, used very fine tweezers/a tool to pick out the gunk carefully.
Alright Ill give it a shot, my problem is the car wont start and Im trying to find the issue🤣 Thank you for the input!
 

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If you haven't already, check the main things - fuel, air, spark. If you can at least identify the one missing, you can narrow down the bad parts.
 

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Discussion Starter #9
Well we have all 3....But one of my fuel injectors is leaking(I just replaced seals and filters) so idk if that will cause an issue. For air I should have that, but how would I check?
 

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air is almost a given unless you have a giant rats nest or rags or something else clogging the intake tract fuel at the rail is good but that doesn't mean its getting into the hole are your spark plugs wet with fuel?
give it a shot of starting fluid to see if it will ingnite
 

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Discussion Starter #11
air is almost a given unless you have a giant rats nest or rags or something else clogging the intake tract fuel at the rail is good but that doesn't mean its getting into the hole are your spark plugs wet with fuel?
give it a shot of starting fluid to see if it will ingnite
Yeah then were good with air, everything has been cleaned and the engine was rebuilt. Would I just give a spray through the throttle body?
 

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air is almost a given unless you have a giant rats nest or rags or something else clogging the intake tract fuel at the rail is good but that doesn't mean its getting into the hole are your spark plugs wet with fuel?
give it a shot of starting fluid to see if it will ingnite
A faulty/dirty IAC valve can also be an issue. I had some issues with mine - it had a lot of carbon buildup. Pulled it, cleaned it with carb cleaner and car started a lot better and idles well now.
 

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A faulty/dirty IAC valve can also be an issue. I had some issues with mine - it had a lot of carbon buildup. Pulled it, cleaned it with carb cleaner and car started a lot better and idles well now.
this will not cause the car not to fire off
 

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You might want to touch up some of those solder joints on the back of the board. With a quick peek at you picture I spotted a couple fix'n to give you trouble.
290138


Be sure to clean off the coating around the joint with alcohol and swabs, foam ones if you can, before heating.
(Foam swabs work better than Q-tips because they don't have the little fibers that catch on and can damage the delicate parts)
Who's the warranty from?
 

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Discussion Starter #16
You might want to touch up some of those solder joints on the back of the board. With a quick peek at you picture I spotted a couple fix'n to give you trouble.
View attachment 290138

Be sure to clean off the coating around the joint with alcohol and swabs, foam ones if you can, before heating.
(Foam swabs work better than Q-tips because they don't have the little fibers that catch on and can damage the delicate parts)
Who's the warranty from?
Okay Ill do that! I assume its from Mitsubishi, I dont believe its ever been replaced. I know the whole history of the car so. Its been in the family, in sorts
 

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Someone's been in there. As ROSSB said those caps were replaced and soldered kind of sketchily.
That's not factory. Besides, the factory doesn't put warranty stickers on the ECU. Or write on the connector with a sharpie.
Perhaps it's the original ECU that someone had repaired?
 

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Discussion Starter #18
Huh it very well could be, Ill have to ask some family members about it. I dont know much about the eltrical side of cars so
 

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A word of caution.........

Unless you have good soldering/desoldering equipment, and experience.......you may find that working on this circuit board difficult.

It is a four layer/plane board(top, bottom, and "ground" and "+5 volt" internally), with many selectively positioned plated-through component lead holes........that are closely fitted to the leads(capacitor leads, for example) which pass through them.

Trying to remove through-hole leads can be difficult/frustrating......which can result in the plated-through hole being physically pulled out. This is probably why the replaced parts, on your board, were added "external" to the holes.

BTW.....If I recall correctly, cylinders 2 & 6 firing signals are generated on the small vertical circuit board "below"(recall that the ECU is mounted vertically) the two replaced capacitors. The other two firing signals come directly from the main integrated circuit.

Hope this helps.

Kevin
 

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Discussion Starter #20
This does help but it seems like youre speaking a different language😂😂My knowledge of electronics is very limited as of right now. So I will most likely look at taking it to someone to make sure its done right. Thank you for your response!
 
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