Need replacement ECU

HemiRick

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Jun 28, 2020
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I have an ECU from my 91 that I've replaced caps in, but did not fix it....Anyone have any idea if there's a person/company that will look at it/want it for core, worst case? Your ECU I'd say is beyond repair w all that corrosion.
 
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Mustang5L5

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Internal power supply (for the 5v) is another weak part of the ECU. If the caps blow, they can’t protect it from surges and it can fry.

also don’t overlook a burned PIN 46 trace which is quite common as well.
 
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Mustang5L5

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Voltage regulator is what I meant to say.

Left pin is input (12V) center is ground and the right pin should be 5V output. I haven't peeked inside an A9L in a while but from this stolen pic it looks like there may be 4 of them. Would need to see the writing on them to pull specs.

1603375251046.png
 

Scrapla347

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Apr 23, 2020
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Is that Diablo's 4-bank chip?


And yeah... That is [the] worst ECU I have ever seen in all my years. :rlaugh:


Put a Stangnet sticker on it and frame it! LoL
I'm not sure what chip but I do know I went to Diablo Motorsports and the tuner was Scott Beers. Very cool guy very heavy Canadian accent. I was a last minute customer and showed up without a blank chip luckily he had this one and spent about a hour on my car before it started getting outta my price range. He couldn't get my ECU back easily and didn't want to break any wires so we left it on the floor board and I never fixed it. My car sat for years cause I made some dumb mistakes and when I finally got back to it the ECU looked like a coral reef. I think I'm going to just get the Micro Squirt and try to use the auto tune feature. I also heard the Micro Squirt can tune with an AFR gauge and i can ditch my mass air.
 

Scrapla347

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Apr 23, 2020
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I'm not sure what chip but I do know I went to Diablo Motorsports and the tuner was Scott Beers. Very cool guy very heavy Canadian accent. I was a last minute customer and showed up without a blank chip luckily he had this one and spent about a hour on my car before it started getting outta my price range. He couldn't get my ECU back easily and didn't want to break any wires so we left it on the floor board and I never fixed it. My car sat for years cause I made some dumb mistakes and when I finally got back to it the ECU looked like a coral reef. I think I'm going to just get the Micro Squirt and try to use the auto tune feature. I also heard the Micro Squirt can tune with an AFR gauge and i can ditch my mass air.
 

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stanglx2002

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reading through the comments on this one item I noticed wasn't brought up which is the fact the Diablo chip has to be plugged into J3 Port. This port is notorious for giving issues as well with connectivity to the chip. I used to run a Moates Chip years ago before going Megasquirt chasing my tail with issues of the car just to come find out it was the chip. So even if you do get a good ECU this still may become an issue.

If you go with a standalone unit you have a lot more additional features and upgrade options that are feasible that you didn't have with the factory parts.
 

Noobz347

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reading through the comments on this one item I noticed wasn't brought up which is the fact the Diablo chip has to be plugged into J3 Port. This port is notorious for giving issues as well with connectivity to the chip. I used to run a Moates Chip years ago before going Megasquirt chasing my tail with issues of the car just to come find out it was the chip. So even if you do get a good ECU this still may become an issue.

If you go with a standalone unit you have a lot more additional features and upgrade options that are feasible that you didn't have with the factory parts.

I use Deoxit contact cleaners and protectants. I still run a Diablo 4-bank chip and A9L in my 86. I had the issues you're speaking of until I started using this. I also run a strip of Gorilla tape over the chip once it's in place. Not to "squish" it in but just to keep it from vibrating or moving.

I use the same stuff on the EEC connector.
 
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Black1987

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Is there any major difference from the A3M to A9L?

I ran both of these in my 1993 I sold, but kept these as spares for the current 1993
 

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Mustang5L5

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Is there any major difference from the A3M to A9L?

I ran both of these in my 1993 I sold, but kept these as spares for the current 1993

5 degree temp difference in A/C max engage. (247 vs 242) but that’s about it. Some minor hardware changes. I believe the A3M has a better internal heat sink.

consider them equal
 
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Scrapla347

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Apr 23, 2020
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South Florida
reading through the comments on this one item I noticed wasn't brought up which is the fact the Diablo chip has to be plugged into J3 Port. This port is notorious for giving issues as well with connectivity to the chip. I used to run a Moates Chip years ago before going Megasquirt chasing my tail with issues of the car just to come find out it was the chip. So even if you do get a good ECU this still may become an issue.

If you go with a standalone unit you have a lot more additional features and upgrade options that are feasible that you didn't have with the factory parts.
Yea this car sat for years and was running perfect before parked. I have a new gas tank and planned on getting it started and chasing down all the leaks until I noticed the ECU was toast. I have been overthinking this day and night rather to go stock ECU and hope my chip is still good or just get the Micro Squirt to get it running then use the auto tune feature to tune it. I was told I can lose my MASS AIR sensor if I go with the Squirt and just run an A/F gauge to tune with.