ECU smells funny, is it bad?

[devonkyle77]

i just did my s14 sr swap, and my car is not getting fuel or spark. after checking the more obvious things, i pulled the ecu out to take a look. not sure why i did, but i smelled it. it smells kind of like a burnt match. does that mean its bad? i am having a hard time finding anyone around that has a running car that uses a WC ecu, so i could just test it that way.

[TanaMU]

Quite likely, yeah, something blew. Possibly from an improperly connected wire? or wrong injector impedance?


Open it up and look for scorch marks.

I'd be careful connecting another ecu because if the wiring is in fact messed up, you'll just burn out the new ecu too..

[Katsumbhong]

Wires grounding out on themselves or the ECU getting wet can cause the ECU to burn out or Worst Case Scenario, parts of the wiring harness to burn out. Replacing body harnesses or certain ecu wires is tedious.

[OBEEWON]

If it smells sweet then that's really bad.

Hey I never saw pics of your S15 swap.

[GSXRJJordan]

Burnt silicon has a very distinct smell - there's a power lead that likes to get burnt in bad installation jobs, and I've actually repaired that lead before - open the lid of the ECU, look at the biggest/thickest lead going along the top layer of the board, and look for "sugaring"/a black spot. That'll tell you if it's fried.

Oh, and don't borrow someone else's ECU and try it in your car, take YOURS and put it in THEIR car lol.

[devonkyle77]

i think what made the ecu go bad was i had the battery ground going to the stud in the fusebox, and the alternator lead going to the intake mani. after i resolved that situation by putting the wires where they need to go, and replacing the 100a FL i think this all happened.

[projectRDM]

i think what made the ecu go bad was i had the battery ground going to the stud in the fusebox, and the alternator lead going to the intake mani. after i resolved that situation by putting the wires where they need to go, and replacing the 100a FL i think this all happened.

You burned it for sure. Now that we got your wiring squared you should be fine with replacing it, or open it up and see how bad the damage really is.

[GSXRJJordan]

Yup yup. I've actually repaired a SR20 redtop ECU by anchoring a pin right in the middle of the burned trace (further back from the burned spot, naturally), and jumping a wire from the pin on the back to the new pin.

You need a really small drill bit, preferably on a dremel, and a small piece of fairly large-strand wire (I used a strand off of a 0/1GA amp wire).

Post up a pic of the inside of the ECU!

[devonkyle77]

here you go jordan
http://i84.photobucket.com/albums/k4/devonkyle77/ecu1.jpg

[GSXRJJordan]

Ahhh, *that looks nothin like* a redtop board, took me a minute to find what I was lookin for, but yeah, you fried a power lead. Note the "sugaring" (looks like burned sugar on top of the board) - that's what you smell, and it gets worse when you send power to it.

http://img123.imageshack.us/my.php?image=ecuhighlightedkk2.jpghttp://img123.imageshack.us/img123/9075/ecuhighlightedkk2.jpg (http://imageshack.us)

It looks repairable, but I'm no expert. I'd say take it to a TV/electronics repair shop and ask 'em what it would cost. Probably less than an hours work, so like $40?

[devonkyle77]

its an s14 sr WC ecu sir.

[GSXRJJordan]

yup, saw that, edited post. If you took another one of the area I circled in yellow with no flash, but maybe a incandescent light on it, I could see more. If you put some acetone on a Q-tip you can clean up the burnt section and see if the lead is completely separated... if it is, you have to re-anchor it in order to repair it.

[devonkyle77]

how about i send it to you jordan? :)