Stuck Injector Fried My ECU?

**freeebird** · 05-23-2016, 12:41 PM

That's basically what I'm hearing from Simon after getting less than 10 hours out of their rebuild. With that, they are telling me my one year warranty is no good. Their tech who came to this conclusion is supposed to call me, but I'm not getting a warm fuzzy feeling about this.

I'll gladly provide details which lead me to this point, but my primary question is, can/will a stuck injector fry the fuel drivers in a ECU? If so, why didn't it fry another A32 and a Brucato unit that we ran to confirm the ECU was bad?

**TEXAS20225** · 05-23-2016, 12:55 PM

seems like it should have fried two holes then if that is what happened to ecu because it fires in pairs , im my experience a stuck injector stuck open or stuck closed will flood that hole or lean that hole i dont think toast the ecu i clean my own injectors so i dont have to listen to the blah,blah,blah that will be 285 more deal i have found a very few injectors in the last 8 years that were bad it takes 9 volts to fire the injector btw good luck mister im assuming its a 3.0

**freeebird** · 05-23-2016, 12:57 PM

2000 225 Promax

**freeebird** · 05-23-2016, 01:00 PM

This is basically the message they left after receiving my ECU...

"It is burned up inside. #5 or #6 injector stuck open which burned those drivers, then burned the #3 and #4 injector drivers. ECU is toast, but what caused the problem was a stuck open injector. Need to have your mechanic look at this". Not an exact quote as she was obviously reading tech notes (and I'm typing with one hand) along with what I had told her in the note I sent.

**Baja170** · 05-23-2016, 01:35 PM

Sounds odd. Good luck getting it all squared away.

Originally Posted by TEXAS20225

i clean my own injectors so i dont have to listen to the blah,blah,blah that will be 285 more deal i have found a very few injectors in the last 8 years that were bad it takes 9 volts to fire the injector btw good luck mister im assuming its a 3.0

Do you know anyone who has a Injector test setup for sale? Or can you PM me your setup. I have 28 of them in all our boats and I would LOVE to be able to keep a closer watch on them myself. Plus I have a lot of neighbors with Merc outboards and 3 pretty large marina's on the lake and none of them have the stuff to do them. Please PM so as not to hijack this thread any more than I already have.

**W2F a V-King** · 05-23-2016, 05:02 PM

Sorry but I would have to raise the BS flag on that shops diagnosis.

I do not have an EFI merc, but have worked on countless EFI/DFI fuel injected vehicles since the first ones came out on GM and Ford vehicles. Late 70's GM and 1985 on Fords. Master Ford Certified tech and Shop foreman in Ford Dealerships..Retired now.

Never...Never have I seen a PCM/ECU/ECM or the like loose an injector driver over it being stuck open or closed. A shorted injector should pop the key power feed circuit to the injector bank. Not the ECU...on car/trucks anyway..

I sure hope they make it right with you.

A quick easy test with an ohm meter of the injectors would tell you if the injectors have a resistance value problem. The ECU has no way to know, or care if the injector is stuck closed or hung open. It controls the ground side of the injector circuit (car and truck anyway..like I said I don't have an EFI merc...yet) So if the injectors all have the same resistance within an ohm or so of each other, the injectors did Not fry the ECU......they are trying to squeek out of their responsibility...JMHO

James

**StratosVT** · 05-23-2016, 05:54 PM

It's either a BS excuse or the person doesn't know what they're talking about. I don't think a stuck injector would have any effect at all on the ecu. The ecu controls the injector....the injector doesn't control the ecu. If the injector was stuck it would just result in too much fuel to the cylinder. Think about it.....there is constant fuel pressure at the fuel rail and thus the closed injector. The injector opens for a millisecond to let fuel through when the ecu sends an electrical pulse... The ecu bursts electrical pulses off & on constantly....the injector being stuck has nothing to do with the pulse it's receiving. The only thing that would happen is the cylinder would get constant fuel from the open injector because it would still flow from the fuel rail through the injector while there is no pulse (open signal) from the ecu. Your motor would run like crap but thats about it.

FYI...Some guys that drag race outboards tune their ecu's to run the injectors at 100% duty cycle which essentially means that the injector driver is on all the time at full throttle. Even those people don't have injector driver problems.

**David - WI** · 05-23-2016, 05:57 PM

Sounds like complete BS, I've never heard of anything like that.
Maybe try this to check them (although if it ran on all 6 with the Brucato or Merc ECM then the injector isn't stuck):

http://injectorrepair.com/knowledge-base/

Sometimes Injectors Get “Stuck” Closed After Sitting Around Too Long:Use a small 9 volt battery to check for stuck injectors before installing them in an engine. Just listen for a click. If it clicks, then it is not stuck. If it is stuck, a light tap on the body of the injector can usually free it. BE GENTLE!!!

**freeebird** · 05-23-2016, 07:03 PM

Talked to Simon's tech and got the same story that it was another electrical failure which burned up my ECU. I believe his name was Dan, and he says he has had this happen many times. Something about an injector or other electrical component grounding out and backfeeding through the ECU and burning up the drivers.

I know Simon is, or at least was, a sponsor here, and I'm not trying to bash them, just trying to understand what happened, and more importantly, what happens next. They will not cover this under their warranty, so I'm out $500 plus whatever it's going to cost to replace this ECU. They offered me another A32 for $1,100 with the same warranty I had before.

**freeebird** · 05-23-2016, 07:14 PM

Just to recap, this started with me running the motor around 6,000 for a short period of time, maybe 2-3 minutes, after cruising around 5,000 for an hour or so with no issues. Came off plane, idled a minute, then went to take it back up again. When I hit the pedal, it bogged really badly and didn't want to go. Got it up on plane, but it only turned around 3,000. Not missing or anything, but just no power. Then it became a race with the fuel gauge which I could literally see moving as I tried to make it back to my dock.

It became obvious after about 5-6 miles that I wasn't going to make it, so I headed for the closest ramp and called a friend who took me to get my truck and trailer. Started it in gear to get it loaded, and it sat for about 5 months before I was able to get it checked out. Motor wouldn't start until the mechanic tried another ECU. Good compression, good fire, but it didn't run worth a crap. Now, I'm not sure where to start and haven't been able to reach him.

**Euroski** · 05-23-2016, 08:05 PM

I would check the resistance of the injectors and see if they are within OHMs spec. I would think the only way to "FRY" the ECU if there is a short somewhere between the ECU and injector(harness). And then it should "FRY" the test ECU! That's my 2 cents.

**TEXAS20225** · 05-23-2016, 09:35 PM

is it a merc brain a32 maybe send me your injectors ill check them for nothing just for the sake of knowing ill pm u my address if interested did he reflash your ecu???

**TEXAS20225** · 05-23-2016, 09:42 PM

i think i just got the picture all you bought was the ecu from him and it fried itself now( but your stuff did it) and he wont stand behind his warranty he can reflash any 824003 ecu to a a32 curve sound like there may be a fox in the hen house hold on to yer wallet

**W2F a V-King** · 05-23-2016, 09:50 PM

If the ECU injector driver or circuit fails on the grounding side and keeps that injector/s at 100% duty cycle, that's not good for the injector/s.
An injector is just electrical solenoid that is pulsed, and measured in duty cycle percent (On Time in one cycle of the engine), measured in ms ( How Long It Stays On in thousands of a second..ms). Injectors can be damaged if kept in the on position to long. Most injectors I am familiar with (cars and trucks) don't want to see a dwell time or duty cycle longer than 80-85%.

MHO would be to shop for an ECU elsewhere. And have your injectors checked/replaced as necessary. Pull your wiring harness off the motor and inspect all of it (every wire and connector)for any sign of failure, shorts, melt down, etc... A shorted harness can reek havoc on any system. Even a rat chewed harness could be problems.

Actually before you spend any $$ pull the harness and check it, check the resistance of your injectors and see what you can find before you pull out your wallet.

Does any of these ECU's have any data logging capabilities? Scanner to view live data with motor running or trying to run in this case?

James

**TEXAS20225** · 05-23-2016, 10:09 PM

the a32 or any 824003 ecu does not record data, i told him send the injectors to me i do all that stuff no charge to him hell send the plenum ill check the harness ill bet a dollar gin a doughnut hole that aint it, here is what ive learned i rebuild only efi merc v6 motors, if you have a ecu with a problem (broke inside) would you think re flashing a new program over the old one it will fix whats broke

i could roof my house with all the bad ecus ive had