Hello to everyone. I need your help in troubleshooting my issue.

I have a 94 Del Sol DOHC Vtec with 235,000 miles and today a capacitor in the ECU was burnt. I was driving with cruise control on at 70mph in and suddenly the engine died. Quick thinking let me coast off the highway and onto a residential street. The smell of burnt electronics was obvious.

I took apart the interior sniffing around and finally traced it to the ECU. I have a lot of Subaru and Toyota experience but my Honda knowledge is lacking. Here is an example image with the capacitor in question highlighted.




I have multiple questions.
I am wondering if the capacitors age caused it to fail or if there is a short somewhere? One leg of the cap connects to multiple ground pins on the ECU plug but I can't easily identify where else it connects.

Does anyone on this forum have experience with the internals of the ECU who could help me determine what caused the burnt capacitor (if it wasnt a short inside the capacitor itself)?

I did quite a bit of searching before posting this thread and it seems that most of the 89+ OBD1 ECU are interchangeable. If this is true could I get any random ECU with the same plugs and try it in my car as a test, to see if it will burn out again? I'd hate to get the right replacement ECU and have it also get damaged.

Is the only difference between the multiple OBD1 ECU with this connector what tune is applied? Could I get an inexpensive ECU of similar spec and buy a chip to get the car working properly again? Alternatively could I remove the PROM from my damaged ecu and transplant it into the ECU from a regular civic? I remember seeing a non VTEC del sol in the junkyard near by and wouldnt mind to spend a little money on the experiment.

Can you suggest another forum to ask on if there is someone there who would be better able to help?

Thank you for your help. I had to borrow a friends car because I am in the middle of building an engine and installing a new final drive for my Subaru and the Honda was supposed to be my reliable transportation!

 

Oh man, that sucks... it's a pretty rare ECU too.

 

you can use any obd1 ecu to test and see, the del sol in the junkyard ecu's probably a p06 which is the nonvtec sohc but will run your sol, you just wont have vtec. now you can use that ecu for parts and unsolder the capsitor and have it soldered in yours, or you can buy another p30 ecu from ebay, or you can send off the junkyard del sol ecu to pheriable.net and have them chip it and program it for your engine and its only 100$

any ecu from a del sol or civic or integra thats obd1 will work,

 

That is the bad thing about electrolytic capacitors. They only have a life of about 10 to 15 years... I know because I had to rebuild many of my old school power amplifiers and I still have a couple that could use some fresh capacitors.

 

Thank you for the help. I was able to find a P06 ECU in the junk yard. Although the layout of the board is extremely similar it isn't exactly the same. I think I will try running the car with this ECU for a while to see if it burns out in the same fashion and if not maybe I will try to find a used "chipped" model for this engine while trying to resurrect the old unit.

I see that there are many off the shelf tunes available. If I do choose to go the aftermarket route can you suggest a good configuration for passing smog? I'd enjoy some extra power but having the car be reliable (functioning knock sensor) and easy to pass California sniffer test is my main concern.

I tried to visit pheriable.net but its not working.

 

This is their site: http://www.phearable.net/

My suggestion is that you email them for best results. They were more than helpful when I was looking for a programmed ECU that didn't have ELD.

 

Phearable isn't working because you spelled it wrong

 

Today I tried the car with a P06 ECU. It didnt start at first so i did my due diligence and checked fuses. The ECU fuses under the hood was burnt so I borrowed the defroster fuse.

It started with a DTC. I checked the code and it was 19 which is the auto transmission lockup solenoid. I then took it around the block many times once it warmed up and had no issues. I went over many bumps, did full throttle while pressing the brakes and cruised.

I'm starting to strongly believe the root cause was a short internal to that capacitor and not in the wiring harness.

Now I have a new question. It seems that some ECU don't have provisions for certain sensors (knock for example). Can any of you suggest an ECU that I can have chipped which will most closely replicate my p30?

Thanks.

 

the p06 is the most common ecu to get chipped, the p28 will run your car just like the p30, i also had a b16 and i used the p28 to run it. phearable.net email them and they will answer any questions you have, they also have a list of ecu that they can chip and program to run any motor.

 

According to an ebay seller who modifies ECUs I need either a P30, P72 or P13 for the knock sensor to work and support a chip with new basemap. Supposedly the p13 is the wrong shape so Ill have to custom fab a mounting bracket.

I did find a couple OBD1 p72 ecu with knock sensor ability but it looks like no one knows how to convert it from automatic to manual or add a chip Its an oddball four plug obd1 with part number 37820-p72-902

http://cgi.ebay.com/ebaymotors/ws/eB...m=190359864373
and
http://cgi.ebay.com/ebaymotors/ws/eB...m=230413977415