ECUflash Breaking up @ 5K +, scratching my head. Lean bandaid?

[ProjectBroke]

Annnddd no change.

 

[brian9397gsx]

It really sounds like an issue with the cmp or ckp signal. Have you load tested the circuits not just ohm'd them out?

 

[ProjectBroke]

It really sounds like an issue with the cmp or ckp signal. Have you load tested the circuits not just ohm'd them out?

I have not, we may try that this weekend.

 

[ProjectBroke]

Update: Changed ROM's, no difference. Have not had a chance to pull the pump/test wiring yet.

 

[ProjectBroke]

Update: Changed out the pump, fuel rail, feed line and filter.

No change.

 

[Mike9490]

so i had an issue like that on e, cleaned my injectors and good to go, not sure how old yours are or how long since they have been cleaned but if its been more then a year i would clean them. also are you sure your gap is'nt to high? also fuel pressure set correctly? sometimes its the simple shit you over look unfortunatly

 

[ProjectBroke]

so i had an issue like that on e, cleaned my injectors and good to go, not sure how old yours are or how long since they have been cleaned but if its been more then a year i would clean them. also are you sure your gap is'nt to high? also fuel pressure set correctly? sometimes its the simple sh** you over look unfortunatly

Injectors were installed in February. Not too much run time on them since. Have thought about swapping them and checking. It’s the only thing in the fuel system we haven’t touched since then. Our fuel pressure did shoot up after the new pump/rail. But adjusted it back down. Has always been 42-43 at idle. Have gapped from .020-.024 with no change. Issue isn’t boost dependent. So gap shouldn’t be a factor.

I still think it’s weak spark. Im not sure how, but it’s what it feels like.

Next steps, swap injectors, COP?, crank sensor, then rummage through the harness and look for problems.

 

[Mike9490]

Injectors were installed in February. Not too much run time on them since. Have thought about swapping them and checking. It’s the only thing in the fuel system we haven’t touched since then. Our fuel pressure did shoot up after the new pump/rail. But adjusted it back down. Has always been 42-43 at idle. Have gapped from .020-.024 with no change. Issue isn’t boost dependent. So gap shouldn’t be a factor.

I still think it’s weak spark. Im not sure how, but it’s what it feels like.

Next steps, swap injectors, COP?, crank sensor, then rummage through the harness and look for problems.

If you have access to another set of injectors i would throw them in real quick, couldn't hurt i tracked my issue around for so long before i cleaned them and will have them cleaned once a year from now on. especially since i dont put that many miles on my car a year so it sits alot.

 

[ProjectBroke]

If you have access to another set of injectors i would throw them in real quick, couldn't hurt i tracked my issue around for so long before i cleaned them and will have them cleaned once a year from now on. especially since i dont put that many miles on my car a year so it sits alot.

I do, we have an identical set in my Evo running fine. Will swap this week and give it a shot. I don’t even care what it is at this point, just need to find it .

 

[m_0ney_pit]

id put the stock 399 maf in use a stock rom scaled for your injectors

 

[ProjectBroke]

id put the stock 399 maf in use a stock rom scaled for your injectors

Negative. Car ran fine on SD rom before being built. Maf should have no effect. But at this point I may try.

I have my money on electrical gremlin.

 

[ProjectBroke]

If you have access to another set of injectors i would throw them in real quick, couldn't hurt i tracked my issue around for so long before i cleaned them and will have them cleaned once a year from now on. especially since i dont put that many miles on my car a year so it sits alot.

Swapped injectors. No dice.

Ran some data logs, lights dim at idle. Bat voltage fine though at WOT. Thought it may correlate. Oh well.

 

[m_0ney_pit]

Just sayin it'll be easier to tune... . Looked at the log the Afr is all over the place no wonder it runs like a turd. Can you not log airflow with speed density?

 

[ProjectBroke]

Just sayin it'll be easier to tune... . Looked at the log the Afr is all over the place no wonder it runs like a turd. Can you not log airflow with speed density?

No, you can’t. That’s how speed density works. You are telling the engine what the volumetric efficiency is. You want another log? Smooth fuel, rough fuel, lean, rich, doesn’t matter. My tune was all over the place from me trying to do SOMETHING that stops it. Current tune on the car runs great. Until 6k. I’ve got logs from last night, load goes up and down, that is the only thing in the log that shows that anything is going on. Fuel is fine, timing is fine. I’ve changed ROMs, Ecus, everything. I’ve had it on a pro tune, I’ve had it on 10’s of my tunes. It’s not the tune. Engine harness becoming damaged somewhere is my current guess.

 

[ProjectBroke]

Here is a log from last night. Cruising at 5500+, it is breaking up this entire time. TPS at 33ish. No boost, 13.7-14.5 afr. Light load. If it WOT it's breaking up, if it's 1/4 throttle, its breaking up. The only factor is it has to be 5500 rpm or above. Any gear, any load, any AFR, any timing.

 

[evil_eagletalon]

Swapped coils yet?

 

[ProjectBroke]

Swapped coils yet?

Coils, PTU, Wires. Yep.

 

[evil_eagletalon]

Cam sensor,

 

[ProjectBroke]

Cam sensor,

CAM and MAP sensor have been changed.

 

[brian9397gsx]

Like I asked before have you checked the signal wires from the cmp and ckp to the pcm? Actually load test them not just a continuity check? I think that's a logical place to start looking. Hell it could just be a simple pin fit issue that at those rpm the vibration is enough for it to loose some continuity that would happen so quickly not to show up on a data log but effect drivability. I see it from time to time on new cars.

 

[ProjectBroke]

Like I asked before have you checked the signal wires from the cmp and ckp to the pcm? Actually load test them not just a continuity check? I think that's a logical place to start looking. Hell it could just be a simple pin fit issue that at those rpm the vibration is enough for it to loose some continuity that would happen so quickly not to show up on a data log but effect drivability. I see it from time to time on new cars.

I did forget to update that one, yes, load tested pcm to cmp, ckp and map with no significant resistance.

 

[Sp1kE]

I'm running into the same issue this year. at 4000. doesn't have to be in boost.
although I find more fuel masks the issue.
Very interested to see your outcome.

 

[ProjectBroke]

I'll keep updating. We have also changed the gap to .018 just in case. No results.

I personally believe something is causing weak spark, and it would have to be wiring at this point.

Everything in the fuel system has been upgraded, everything in the spark system has been changed. Every sensor except Crank sensor has been changed. Issue has not dissipated.

We are on a roller coaster that keeps going down. It's making me cranky.

 

[Denji]

I'm not as knowledgeable as you but I have a suggestion. Have you checked the alternator under load? My understanding is that DSM shuts off alternator at WOT however with evo ECU it will stay on and if not putting out the required juice at higher RPM it could be an issue.

That is more of an obscure idea I guess but once time I had this alternator that put out too much voltage and I then realized that a faulty alternator can look more than one way.

 

[wrencher]

Have you tried removing the ignition capacitor from the ignition coil/PTU power feed circuit?