My 91 SE ( automatic) Max has burned up 2 ECU's. inside the ECU (A18 A83 EA1) there is a IC fastened to the wall of the ECU box that is # HF9907. I have tried Hitachi and the cannot Identify it. Anyone know of a vendor that repairs ECU's that will sell parts for the DIY'er. This IC must be a driver ciruit for the 2,4,and 6 fuel injector because they ohm out good and the wires (injector to ECU) are good but are not working. just don't understand why this circuit is frying.

 

have you ever replaced the injectors?
what about shorts to ground?
what's the resistance on the output wires between injectors 1,3,5 compared to 2,4,6?

if it's frying, it's going out for a reason.

are there any othe rmarkings on the IC in question? often stuff like that isn't replaceable by that part number, but you can find ones that will work through a cross-ref of anything else on it.

 

Do oyu have any mods on this car?
are you knowledgeable of the cars past?
If 2 ecus got fried like that you definitely have someyhing shorting somewhere.
How long was it in the car before frying?
I'll think of dome more stuff once I catch up.

 

The injectors ohm out at 11 and 14 one at 18 going but not enough for me to replace.
The IC markings are HF9907 OJ2. into slot IC611 of the board. do you know where I can get ECU schematics?
I did a search and Xtrip (.org member) had the same problem and said that a mechanic hooked something up wrong in the back of the engine maybe something that should not be hooked up. I cannot see that here all the connectors are different preventing that from happening I have two extra connectors that have caps on them so they don't get hooked up

 

You got one (18) that needs to be replaced for sure.
chances are this is not a diy project for the beginner but you have to find the cause of the problem before you bother replacing/repairing the ecu

 

I bought the car in June 03 the previous owner said the car lacked power. I gave it a full tune up and it ran great I got 23 MPG for about 1 month then the crankshaft broke. I was entering the freeway and it started shifting strange and then shut down. I replaced the engine (block and heads) with a low mile japan import
No mods? yet!
the second ecu did'nt fry right away I drove the car around the block it seemed to run ok still a shifting problem. then when I got home rough idle and the smell of elect smoke from the ECU

 

sounds like you've got a wire somewhere that's shorting out whenever you drive or shift or something...

there's definitely an intermittent problem that you need to fix before you can do much with the ECU. you'll just keep burning them up.

 

echo echo echo

 

sometimes they just have to hear it from 15 people before they believe you.

 

Now all we need are 13 more people

 

not even sure if there's 13 more people on here that know what an injector, ECU, and IC are.....

 

I have replaced IC's and other components before. The parts for ECU's don't seem to be ready available. I'll check for shorts to ground but would like to have these two ECU's ready to go when I fix the short. Hey thanks alot Matt

 

injector, ECU? What are those?

 

not sure about the IC you are looking for, but when I chip Honda ECUs I usually get my Atmel 29c's from here--> www.JDR.com check with them

goldmine-elec.com might have it also

 

This is just me thinking out aloud, but do you think the root cause of the problem may be in the JDM engine itself?? I know a few of you have done swaps with the JDM-spec engine (although I haven't heard of anyone doing a VG swap), but were there any sensors/connections that did or did NOT need to be hooked up?

Like I said, just a random thought here...

 

I checked out my ECU yesterday... yeah, I dont know what I was thinking, its easy to get out just by removing the kickpanels like you said. (i reached in and felt the bolts). Hurry home KLoWn.... get those toys installed