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The ECU switches fuel pump speed based on load.(Airflow) Default is high speed. Once you start the engine and it establishes low load, it switches to low speed. If it dies when attempting to make the switch, that tells you the ECU is trying to do it's job, but there is a break in the low speed circuit. As I already posted, the most common issue is the relay full of water, but simply forgetting to plug the resistor back in will do the same... Unplugging the airflow meter simply puts in into limp mode and deprives the ECU any means of establishing load, so it defaults to high speed and never tries to switch.
While this explains why/when ECU switches between low and high speed operation, it still doesn't explain why when ECU switches pump relay to low speed it also drops ground for MFI pump relay coil. That half of MFI needs to stay closed no matter which state the pump speed relay is in, that's what I'm trying to wrap my head around.

Are you indicating there's logic in ECU that can sense a load problem when it shifts to low speed circuit side and drops out MFI relay pump side because of some kind of imbalance, similar to how a ground fault circuit breaker works? :unsure:
 

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While this explains why/when ECU switches between low and high speed operation, it still doesn't explain why when ECU switches pump relay to low speed it also drops ground for MFI pump relay coil. That half of MFI needs to stay closed no matter which state the pump speed relay is in, that's what I'm trying to wrap my head around.

Are you indicating there's logic in ECU that can sense a load problem when it shifts to low speed circuit side and drops out MFI relay pump side because of some kind of imbalance, similar to how a ground fault circuit breaker works? :unsure:
I missed the part where that was happening... I didn't read all responses, I was just addressing the way the system works, and some common issues I've seen in that system. If it is verified dropping the MPFI BEFORE the engine dies, (which needs to be very carefully verified, as normal operation turns off the fuel pump as the engine dies) that's a pretty clear cut and classic ECU failure.
 

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Discussion Starter · #23 ·
I missed the part where that was happening... I didn't read all responses, I was just addressing the way the system works, and some common issues I've seen in that system. If it is verified dropping the MPFI BEFORE the engine dies, (which needs to be very carefully verified, as normal operation turns off the fuel pump as the engine dies) that's a pretty clear cut and classic ECU failure.
Okay, so I should inspect my ECU? And attempt to narrow in on the problem circuit?

I am fairly proficient at replacing transistors, diodes, capacitors, etc.
 

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Discussion Starter · #25 ·
Yes. Shutting off the fuel pump is a classic symptom of ECU failure.
Is this sort of failure common and limited to certain capacitors or diodes etc in the ECU circuit.

It's behind where my car stereo would go right. I've been looking but I have yet to find a decent guide. Anybody know of one? I am itching to go pull the ECU and start testing the various circuits and pathways
 

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I've seen this exact issue once before where the car stalled after a few seconds unless the MAF is unplugged.

On that car the issue was caused by the resistor for the low speed fuel pump operation was not plugged in by the air filter.

These cars always start with fuel pump in high speed mode and then after a few seconds they switch to the low speed mode unless the load is above a certain level or the MAF is unplugged.
 

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I've seen this exact issue once before where the car stalled after a few seconds unless the MAF is unplugged.

On that car the issue was caused by the resistor for the low speed fuel pump operation was not plugged in by the air filter.

These cars always start with fuel pump in high speed mode and then after a few seconds they switch to the low speed mode unless the load is above a certain level or the MAF is unplugged.
That's the same road I sent him down. But it turns out it's turning off the fuel pump side of the MPFI. (which is likely an ECU issue)
 

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UPDATE :p:p:D:D:p:p:D:p:cool::cool::cool::cool:(y)(y)(y)(y)

After an age here is the update:

New gas: problem not fixed. No difference

Installed new fuel filter, runs a little smoother for the few seconds it does. Engine still dies every time after a few seconds. Not fixed.

Next, I hooked up jumper wires and a multi-meter to the fuel pumps (-) Negative Post and the other was connected to the fuel pump 12V+ line. I started the car while monitoring the voltage I watched the car start up and the volts shoot right to 12v no problem, and then the volts go to zero, as I can hear the relay golden box thing attached behind the carpet on the right side of my centre console. as soon as it loses voltage, the box clicks, and the engine dies, then the box clicks again.

Next, as I see that it is losing power to the pump and that's what the problem is. not the pump itself. The pump is fine most likely. So, I run the jumper wire I have connected in line with the fuel pumps power wire out the window, my brother who is assisting me attaches a connector to it and he clamps it top the 12v + Positive post of three battery. Instantly I hear the pump kick in for the first real time ever that I have actually heard it, I started the engine and it continued to run just fine. Bingo! Problem Identified.

Now a lot of my problems are beginning to make sense.... I was constantly experiencing fuel cut and i could tell I was running lean because I wasnt burning as much gas as regularly and my boost would be horrible spikes and frequent random fuel cuts. Lots of bucking. Perhaps ive been experiencing voltage drop for whatever reason, and perhaps now it's just gotten so bad that the car wont even run for more than 2 seconds. I dont know, maybe someone could offer some wisdom.

Does anybody know what the cause of the problem is or is the one fix fixes all the Hotwire/Relay Mod??

I am so excited to have finally made some solid progress and identified one of possibly several points of failure which are causing my problem.

Would anybody be kind enough to direct me to the guide most appropriate for the problem I am facing? Thank you all!
I currently had a similar problem but the main cause was my ecu fuse under the hood. It starts up fine and the shaking from the motor can eventually move the fuse and stall itself out
 

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Discussion Starter · #30 · (Edited)
Yes. Shutting off the fuel pump is a classic symptom of ECU failure.
(y) Ty, im pullin out the ECU to check it right now.

Since we know it it the ECU that is the source of the problem, next I am going to attempt to diagnose the ECU itself. The question: is there an exact transistor or diode I should check or a certain circuit that you could show me or do I need to one-by-one test each and every component. I hope I can fix it because I would prefer not to buy a new ECU, but I would more prefer a running car so I will buy one if necessary... and available.

Idle Air Control Valve [IACV] dIagnostics:
I tested my IACV which from what literature I could find on it says that terminals 2&1, 2&3, 5&4, and 5&6 each should have an Ohm reading between Ω28 and Ω33; from the info I have unearthed. When I tested my IACV at the terminals I got these numbers:

Resistance Values
  • Pins 2 & 1: Ω25​
  • Pins 2 & 3: Ω26
  • Pins 5 & 4: Ω25
  • Pins 5 & 6: Ω26
For the record I tested the IACV and got the same numbers as I did after I opened it up and cleaned it properly. I also read that a damaged or misfunctioning IACV could damage ones ECU... Maybe the malfunctioning IACV over time damaged the ECU which lead to the problems I am experiencing where my fuel pump cuts out? Or could it be the malfunctioning IACV with its terminals that are all under the required Ω28 - Ω30 (from what I have read at least since I have not been able to find specific IACV info for our cars. Thank you :)
 

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Since we know it it the ECU that is the source of the problem, next I am going to attempt to diagnose the ECU itself. The question: is there an exact transistor or diode I should check or a certain circuit that you could show me or do I need to one-by-one test each and every component.
The most common problems are with the radial electrolytic capacitors failing from age causing erratic current in some circuits, which often have no visual signs. In many cases they leak electrolyte that can corrode and also damage near by components and/or circuit board traces, in these cases there’s usually visual signs of leakage as shown in link @OhioSpyderman linked about removal post #26. Sometimes the electrolyte will damage sub boards attached to main mother board because of ECU being mounted vertically on it’s side, see Important Note: Specific to repair for Stealth ECU (in red) ~ 1/3 down page of the below link.

No matter if there’s visual evidence of leakage or not, original electrolytic capacitors in a ’92 ECU needs to be replaced.


Maybe the malfunctioning IACV over time damaged the ECU which lead to the problems I am experiencing where my fuel pump cuts out? Or could it be the malfunctioning IACV with its terminals that are all under the required Ω28 - Ω30 (from what I have read at least since I have not been able to find specific IACV info for our cars.
The IACV readings you got of 25-26Ω is probably OK if it is the unit with tan colored top, which should be in ~30Ω rage @ 68°. The later solid black units run ~40Ω @ 68°. Ohm readings a little off or infinity reading from a open coil will not damage ECU, just casue a malfunctioning IAC unit. Damage to ECU from IAC usually occurs when one of four coils shorts to housing (ground), causing ohm readings of near zero ohms and complete continuity to IAC metal housing can be read from pin #s for that coil. When that occurs IIRC what happens is burn driver boards that can be seen as in below picture.

click on image to enlarge
 

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The most common problems are with the radial electrolytic capacitors failing from age causing erratic current in some circuits, which often have no visual signs. In many cases they leak electrolyte that can corrode and also damage near by components and/or circuit board traces, in these cases there’s usually visual signs of leakage as shown in link @OhioSpyderman linked about removal post #26. Sometimes the electrolyte will damage sub boards attached to main mother board because of ECU being mounted vertically on it’s side, see Important Note: Specific to repair for Stealth ECU (in red) ~ 1/3 down page of the below link.

No matter if there’s visual evidence of leakage or not, original electrolytic capacitors in a ’92 ECU needs to be replaced.



The IACV readings you got of 25-26Ω is probably OK if it is the unit with tan colored top, which should be in ~30Ω rage @ 68°. The later solid black units run ~40Ω @ 68°. Ohm readings a little off or infinity reading from a open coil will not damage ECU, just casue a malfunctioning IAC unit. Damage to ECU from IAC usually occurs when one of four coils shorts to housing (ground), causing ohm readings of near zero ohms and complete continuity to IAC metal housing can be read from pin #s for that coil. When that occurs IIRC what happens is burn driver boards that can be seen as in below picture.

View attachment 307542 click on image to enlarge
The IAC resistances seem fine to me as well since all 4 are so close to each other. Plus the IAC not working might allow the engine to stall if it was faulty but the engine would have also stalled when the maf was unplugged and when you ran pump straight from the battery which it did not. Also if IAC caused stall, the ground from the ECM to the MFI would not cease causing the MFI click and MFI voltage drop to 0V to occur until after the engine stopped ending the crank/cam signals to the ECU. That's opposite of your observations.
Finally, I said back in my post #18 and giving my reasoning why.. I believe the most likely problem is the ECU. I have tried to think of any "out there possibilities" to account for the MFI to click open before the engine stalls besides the ECU being bad and cutting the ground. Could the speed relay be filled with water or the speed relay coil be toast and directly shorted across itself, or relay pins be shorted to pin 1 causing voltage and amperage to quickly drop as soon as ECU applies ground to pin 1 to shift to slow speed circuit? If so could voltage drop low enough causing the MFI coil to allow the MFI pump contacts to open/click first followed by car stalling just after from pump stopping? Or could a shorted low speed resistor or a partially shorted circuit to ground exist after resistor and before splice connection with high speed wire? Using Ohm's Law at resistor(0.9 ohms) and beyond....V/R=I...so 11-12v/0.9ohms= <15amps fuse ...so even with dead short to ground fuse won't blow. Before relay and partial short to ground.... as voltage drops the MFI acts like circuit breaker and opens before fuse gets hot/amps high enough to blow? I guess if it were me, putting the mental masterbation aside, before I bought a new ECU I would take 15 min and pull the speed relay off the connector, use a 16G piece of wire stripped on both ends, and push 1 end into connector port 3 and the other end into connector port 2..safely set it down so it can't short to metal.....and start her up. If it shuts off buy/fix ECU..if runs make jumper formal,stable and wrapped/insulated.
 

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Discussion Starter · #33 ·
The most common problems are with the radial electrolytic capacitors failing from age causing erratic current in some circuits, which often have no visual signs. In many cases they leak electrolyte that can corrode and also damage near by components and/or circuit board traces, in these cases there’s usually visual signs of leakage as shown in link @OhioSpyderman linked about removal post #26. Sometimes the electrolyte will damage sub boards attached to main mother board because of ECU being mounted vertically on it’s side, see Important Note: Specific to repair for Stealth ECU (in red) ~ 1/3 down page of the below link.

No matter if there’s visual evidence of leakage or not, original electrolytic capacitors in a ’92 ECU needs to be replaced.


The IACV readings you got of 25-26Ω is probably OK if it is the unit with tan colored top, which should be in ~30Ω rage @ 68°. The later solid black units run ~40Ω @ 68°. Ohm readings a little off or infinity reading from a open coil will not damage ECU, just casue a malfunctioning IAC unit. Damage to ECU from IAC usually occurs when one of four coils shorts to housing (ground), causing ohm readings of near zero ohms and complete continuity to IAC metal housing can be read from pin #s for that coil. When that occurs IIRC what happens is burn driver boards that can be seen as in below picture.

View attachment 307542 click on image to enlarge
Thank you so much for all the info you have helped me with so far. I checked out the link and read the whole page, those radial cylindrical shape capacitors that bulge at the top and sometimes the bottoms leak which are obviously harder to detect than a top capacitor leak. Are these the same ones as in the links below? Or do other components fail often? Or just the faulty 42-year-old electrolytic capacitors that stop functioning I wonder...

Like this kind??? HD 100 Pcs 8 X 11mm Radial Aluminum Electrolytic Capacitors 470uf 25v for sale online | eBay

I still haven't pulled it out, got to tired last night. Going to hopefully go out now and pull it out. Already researched the process last night/this morning (whatever) so it should go quickly. I will pull it out and open it up and examine as well as posting pictures of the board itself.


I currently had a similar problem but the main cause was my ecu fuse under the hood. It starts up fine and the shaking from the motor can eventually move the fuse and stall itself out
Which specific Fuse are you speaking about and where is it located? Is it in the fuse/relay box under the hood located sort of behind the left headlamp bucket from the perspective of standing at the front and looking into the engine bay?

Thank you


Could the speed relay be filled with water or the speed relay coil be toast and directly shorted across itself, or relay pins be shorted to pin 1 causing voltage and amperage to quickly drop as soon as ECU applies ground to pin 1 to shift to slow speed circuit? If so could voltage drop low enough causing the MFI coil to allow the MFI pump contacts to open/click first followed by car stalling just after from pump stopping? Or could a shorted low speed resistor or a partially shorted circuit to ground exist after resistor and before splice connection with high speed wire? Using Ohm's Law at resistor(0.9 ohms) and beyond....V/R=I...so 11-12v/0.9ohms= <15amps fuse ...so even with dead short to ground fuse won't blow. Before relay and partial short to ground.... as voltage drops the MFI acts like circuit breaker and opens before fuse gets hot/amps high enough to blow? I guess if it were me, putting the mental masterbation aside, before I bought a new ECU I would take 15 min and pull the speed relay off the connector, use a 16G piece of wire stripped on both ends, and push 1 end into connector port 3 and the other end into connector port 2..safely set it down so it can't short to metal.....and start her up. If it shuts off buy/fix ECU..if runs make jumper formal,stable and wrapped/insulated.
Just to clarify for me, which relay is the "speed relay" is this the MFI or the Relay and accompanying resistor located beneath the air box? I keep hearing the speed relay referanced and I'm always wondering which one it is. Thanks
 

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Discussion Starter · #34 · (Edited)
So, I pulled the ECU. In about 3 seconds I spotted a major issue that just so happens to be beside the largest electrolytic capacitor on the board. It has leaked from the bottom its clear to see the leak trail it left, and it devoured what I think was a resistor (perhaps a diode) beside it and it is covered with corrosion as you'll see in the images. It also leaked out another side of itself and corroded two other pins that you can see in the pictures also. I will circle them in red just to be clear.

So far, it is obvious to me that the leaking capacitor(s?) needs to be replaced, as well as that resister labeled "C6" that is circled in red in one of the photos from different angles. The other damage from the same leaking capacitor you will also see from multiple angles and circled in red. You'll be able to see what I am talking about.

If the images below will not load for you; then I made a MEGA Upload Folder to view them: 28.53 MB folder on MEGA

Please, any help will be much appreciated. Thank you.💪🔧🔨🔋








 

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Thank you so much for all the info you have helped me with so far. I checked out the link and read the whole page, those radial cylindrical shape capacitors that bulge at the top and sometimes the bottoms leak which are obviously harder to detect than a top capacitor leak. Are these the same ones as in the links below? Or do other components fail often? Or just the faulty 42-year-old electrolytic capacitors that stop functioning I wonder...

Like this kind??? HD 100 Pcs 8 X 11mm Radial Aluminum Electrolytic Capacitors 470uf 25v for sale online | eBay
The radial cylindrical shape electrolytic capacitors are the biggest problems because of age and heat cycles. The ones Mitsubishi used in early ‘90’s started failing after ~ 20 or so years. Other components even including ceramic capacitors hold up much better and don’t fail often when not affected by some other failure.

Yes similar to ones you linked but those have wrong micro-farad (µF) and voltage wouldn’t work as replacement for the one 47 µF 50 volt capacitor you need. The µF rating MUST be same as one being replaced and the voltage needs to be same as or higher than one replaced. The three correct µF and voltage currently in you ECU is shown at bottom of bellow link.


Just to clarify for me, which relay is the "speed relay" is this the MFI or the Relay and accompanying resistor located beneath the air box? I keep hearing the speed relay referanced and I'm always wondering which one it is
I'm sure he's talking about one below air box as that one only controls the speed of fuel pump and I also often refer to it as pump speed relay. Mitsubishi literature only refers to it as fuel pump relay, which is sometimes confusing since one side of MFI relay actually starts and stops fuel pump by supplying or removing battery voltage.
 

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You can send off the ECU to get repaired, and from the looks of it, I think that’s the level of repair it needs. It’s not just a capacitor change, but you’re also replacing other components and possibly repairing board traces. You have to remove and reapply the special coating. And then it would be beneficial if you had a testing rig. ECU repairs of this nature are best left to the professionals.

If you plan on keeping the car, you should invest in a new ECU. I would get a chrome ECU if you’re not doing anything wild. IMO, it’s better to start with a new, known quantity than try to repair a nasty 1G ECU.


Sent from my iPhone using Tapatalk
 

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Discussion Starter · #37 ·
Yes similar to ones you linked but those have wrong micro-farad (µF) and voltage wouldn’t work as replacement for the one 47 µF 50 volt capacitor you need. The µF rating MUST be same as one being replaced and the voltage needs to be same as or higher than one replaced. The three correct µF and voltage currently in you ECU is shown at bottom of bellow link.
Yes, thank you of course, I got a lot of info from the link you linked. Thank you. Buying the correct capacitors and replacing them would be child's play for me. The one component I am not sure the exact specs of or where to obtain the specs for is the Surface Mount Ceramic Capacitor labeled C6 that is besides my most obvious leaking capacitor which is labeld "C104" on the motherboard and is 100uf/16v. Of course, if I attempt it, I will replace all three capacitors, but I still need to learn more about that Ceramic Capacitor labeled "C6"that got leaked all over from damn Electrolytic Capacitor "C104"

If anyone can share any insight on the Ceramic Capacitor labeled "C6" I would be much appreciated.

I'm sure he's talking about one below air box as that one only controls the speed of fuel pump and I also often refer to it as pump speed relay. Mitsubishi literature only refers to it as fuel pump relay, which is sometimes confusing since one side of MFI relay actually starts and stops fuel pump by supplying or removing battery voltage.
Thank you for clearing that one up for me. I wonder if with a multimeter I could test the relay to determine if it functions under normal conditions? I also wonder what measurements to take on it to determine if it needs replacing. I could always open it up and make sure it is not "full of water" like others have suggested; last time I had it out while troubleshooting this problem in the beginning and I really don't think there is water in there, but I may as well check it.

Or does the obvious damage to my ECU that I documented with many photos in Post #34 tend to be the source of all my hardships and problems.



You can send off the ECU to get repaired, and from the looks of it, I think that’s the level of repair it needs. It’s not just a capacitor change, but you’re also replacing other components and possibly repairing board traces. You have to remove and reapply the special coating. And then it would be beneficial if you had a testing rig. ECU repairs of this nature are best left to the professionals.

If you plan on keeping the car, you should invest in a new ECU. I would get a chrome ECU if you’re not doing anything wild. IMO, it’s better to start with a new, known quantity than try to repair a nasty 1G ECU.
If I can learn more about the damaged component "C6" (Ceramic Capacitor that got leaked all over) I am more than capable of cleaning up the mess from the leaked capacitor and change out all 3 Electrolytic Capacitors for modern versions. As well as that ceramic "C6" capacitor.

The "Special Coating" looks like thick varnish, maybe a little more sophisticated but it wouldn't be all that hard to find out what they used; or simply use a more advanced modern equivalent. Silicone Potting Compound comes to mind (Once I verified my repair did in fact work)

It's just that I am not a rich guy so If I can fix it myself, I will try to do it myself. Then if I can't fix it, I can send it in to be repaired by the pros.


What is this CHROME ECU all about? Wouldn't that require a whole lot of extra work configuring it to work or is it just plug-an-play. I would probably need a tune afterwards. Putting in an aftermarket ECU for a mostly stock engine makes me feel un-easy. Then again, I don't understand anything about going the CHROME ECU route. Perhaps you could please enlighten me?

Thank You
 

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So far, it is obvious to me that the leaking capacitor(s?) needs to be replaced, as well as that resister labeled "C6" that is circled in red in one of the photos from different angles. The other damage from the same leaking capacitor you will also see from multiple angles and circled in red. You'll be able to see what I am talking about.
That’s classic electrolytic capacitor leakage, which requires capacitor replacement and board cleaning with alcohol. That 100 µF, the 22 µF and the 47 µF need to be replaced, with correct polarity installation. You would need to lightly scrap around/under side board legs pins and around C6, then use isopropyl alcohol and tooth brush to scrub those ares good to remove corrosion residue.

I’m not sure if componet in C6 location is damaged or not, possibly just covered with corrosion and/or residue. I can’t tell for sure but it is probably a surface mounted (SMD) capacitor, simular to one above your red circle of C6 and on other side of side-board in location C27.
 

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Discussion Starter · #39 ·
That’s classic electrolytic capacitor leakage, which requires capacitor replacement and board cleaning with alcohol. That 100 µF, the 22 µF and the 47 µF need to be replaced, with correct polarity installation. You would need to lightly scrap around/under side board legs pins and around C6, then use isopropyl alcohol and tooth brush to scrub those ares good to remove corrosion residue.

I’m not sure if componet in C6 location is damaged or not, possibly just covered with corrosion and/or residue. I can’t tell for sure but it is probable a surface mounted (SMD) capacitor, simular to one above your red circle of C6 and on other side of side-board in location C27.
Thank you for the advice on cleaning the board. I am already aware of polarity on electrolytic capacitors, it's indicated by the grey line running down one side of the capacitor corresponding with the side of the capacitor where the negative pin resides. I would make note of these features before I began.

As far as C6 SMD Ceramic Capacitor being just covered in leakage from the 100uf capacitor and perhaps still functioning fine once cleaned up, that would be a bonus.

I look at it all like this. I could probably fix the ECU myself for $15 or $20. Perhaps even free considering I have hoarded motherboards from all manner of electronics for years now and they are full of those style Capacitors. May just be able to salvage high quality ones if I get lucky and they are of the same Ultra Farad and Voltage rating as the ones I need.

The alternative is spending possibly $200 on sending my ECU away to have it fixed by professionals.

I mean; replacing capacitors and cleaning boards is fairly simple procedure if you have the equipment to do so (which I happen to have). Have other members succeeded in fixing they're ECUs themselves? Even if I didn't succeed in fixing it myself, I could always turn around and send it off to be fixed or go the CHROME ECU way as was suggested just 2 posts ago. I do not know how smart of an idea that would be. Is there a lot of work in converting to chrome ecu?
 

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Thank you for the advice on cleaning the board. I am already aware of polarity on electrolytic capacitors, it's indicated by the grey line running down one side of the capacitor corresponding with the side of the capacitor where the negative pin resides. I would make note of these features before I began.

As far as C6 SMD Ceramic Capacitor being just covered in leakage from the 100uf capacitor and perhaps still functioning fine once cleaned up, that would be a bonus.

I look at it all like this. I could probably fix the ECU myself for $15 or $20. Perhaps even free considering I have hoarded motherboards from all manner of electronics for years now and they are full of those style Capacitors. May just be able to salvage high quality ones if I get lucky and they are of the same Ultra Farad and Voltage rating as the ones I need.

The alternative is spending possibly $200 on sending my ECU away to have it fixed by professionals.

I mean; replacing capacitors and cleaning boards is fairly simple procedure if you have the equipment to do so (which I happen to have). Have other members succeeded in fixing they're ECUs themselves? Even if I didn't succeed in fixing it myself, I could always turn around and send it off to be fixed or go the CHROME ECU way as was suggested just 2 posts ago. I do not know how smart of an idea that would be. Is there a lot of work in converting to chrome ecu?
Sounds like you have tools and knowledge to do the radial capacitor replacements. Knowing that, I’d say just do replacement, clean around C6 and pins for side-boards, then just try ECU to see if it works correctly.

I understand you wanting to do it yourself and could save yourself a lot of money, at worst you’d just have to send it in for repair or replace (as you said) if your repair doesn’t correct it. I’ve fixed my ECU, TCU and Tach by simply doing the same, though I did have to buy a spare used TCU just to see where trace went that was completely burnt away when capacitor burnt up along with burning hole in PCB of my original board. Repaired trace, replaced capacitors in both units, now have one in car and a working spare.

If you don’t have correct capacitors or a electronics store near by where you could purchase them, you could just order set from 3SX for $8.96 that comes with an extra 47 µF that wouldn’t be needed in your TT ECU.

The Chrome units are expensive and not needed if your not going to be doing performance tuning and stock re-manufactured units can be purchased for half the price from some local auto parts stores.
 
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