Fuel cut maybe

[2003.5_MSP]

I've had that code and I replaced the pressure regulator control soelinoid to no avail. Don't waste the 80 bucks...

so what did you do to get rid of it?

 

[2003.5_MSP]

also another thought i just had, could it be the ecu ground being faulty... reason i think that is bc its not throwing a code for the p0090, and it seems to happen when i try to build boost... so my logic is if the ground is faulty on the ecu it will not work properly, thus creating the computer not adjusting afr's when im going into boost... so then my next question is, where at on the MSP is the ecu/ecu ground located?

 

[Sport23]

There are several ground pins for the ECU. Look at some of the piggyback install threads, I think the AEM FIC install thread has the pin-out for the ECU. I doubt it is a grounding issue @ the ECU b/c I believe they are redundant.

 

[2003.5_MSP]

There are several ground pins for the ECU. Look at some of the piggyback install threads, I think the AEM FIC install thread has the pin-out for the ECU. I doubt it is a grounding issue @ the ECU b/c I believe they are redundant.

could never now though, ive been having alot of grounding issues lately...

EDIT: alright i just found that thread and imma try this tomorrow, sounds like my issue... will let you guys know if it helps or doesnt affect it

Q: I am trying to tune the FIC but have bucking issues when I hit boost, is that normal?
A: No, MSP's normally have hesitation but they should not buck when in boost. The best thing to do is use a scan tool and check your fuel trims. I had an SSAFC before trading for the FIC and upon removal of the SSAFC, the car bucked when in boost. The only explanation I can surmise is that the long term fuel trim is out of wack most likely because of the AFC altering the fuel for an extended period of time. To reset the fuel trim, disconnect both ends of the battery and touch the terminals together for 30 seconds. Then pump the brakes to make sure there is no juice left in the car. When you first start the car after doing this, it will run rough. The ECU is relearning so you just have to bare with it for a little while.

 

[Sport23]

The MSP can learn some pretty awful fuel trims. Some people on the factory ECU just disconnect their battery every couple months to clear them. It's sad but it works..

 

[2003.5_MSP]

The MSP can learn some pretty awful fuel trims. Some people on the factory ECU just disconnect their battery every couple months to clear them. It's sad but it works..

well if thats the case ill be happy... but i cant wait for a ssafc so i can tune around it though

 

[Dr0]

I think ima install my ssafc this weekend.

but

Surprisingly i did a pull when I was on my lunch break today and HOLY s***!!! IT'S LIKE A NEW CAR!
I took off and gunned it when I hit 1 psi and to my satisfaction my car shot off like a rocket and I spun the tires through most of 2nd and a little ok third...

And it continued to drive fine until it got to operating temp and then it started failing again lol

These cars act so weird...

 

[2003.5_MSP]

I think ima install my ssafc this weekend.

but

Surprisingly i did a pull when I was on my lunch break today and HOLY s***!!! IT'S LIKE A NEW CAR!
I took off and gunned it when I hit 1 psi and to my satisfaction my car shot off like a rocket and I spun the tires through most of 2nd and a little ok third...

And it continued to drive fine until it got to operating temp and then it started failing again lol

These cars act so weird...

thats how it is for me too... but we will see, bout to go do that test and go look at houses... so itll have time to relearn fuel curve it thats the issue

 

[Dr0]

Fuel trim reset doesn't do ne thing...

I can on only speculate as to what the problem is...

Im thinking MAF or coils

I have yet to test them yet so well see

 

[2003.5_MSP]

Fuel trim reset doesn't do ne thing...

I can on only speculate as to what the problem is...

Im thinking MAF or coils

I have yet to test them yet so well see

well that might make since seeing i had a code for the maf before i claned it... how much do coils run for a full set?... but also noticed that im getting boost spike to 10psi? i havent even done no tuning or nothing to turn up the boost, just put 3" tbe on... that wouldnt change the boost levels due to free flowing exhaust would it

 

[Dr0]

3" tbe will flow a lot more then stock and you run into issues with boost creep bc of the increased flow 1-2 psi above normal from what ive heard.

coils are typically about $30 bucks a piece.

And a little update.

from what ive gathered so far is that -
A-the car runs great in open loop operation (the first 5min or so of driving after a cold soak)
And
B- When the car goes in to closed loop at operating temperature the car dumps a ton of fuel as soon as any pressure is introduced into the system (often maxing the fuel trims)
C- After reaching operating temp and going into closed loop the car stays there until 4000-4200 rpm (please correct me if im misled) And the car switches over too open loop again stabilizing the mix ( Since my car tends to boost normally somewhat if i slowly increase my rpms up to the open loop range)

Ok well it seems im getting close to fully understanding this but the one thing that keeps getting everyone confused is people saying this is normal...

I know its not normal bc before this started happening i had hesitation still from the rich mix but it was no where near as bad as what im experiencing now

Someone please shed some light on this, i dont have my wideband installed yet but i watch my trims with my scan tool while i drive and im almost possitive its running really rich and dumping too much fuel into the mix ( due to low power in boost, bad mpg 24-25)

I feel like i am so close to nailing the issue its killing me. and the fact that i can spin my tires all the way through second when my car is cold doesnt help ( i want that feeling available throughout my entire drive cycle ha)

 

[hornsfan10609]

You can spin the tires when its cold for a few reasons, mainly because the SMIC is still cold and hasn't heatsoaked. And because the car isn't fully warmed up so it is running in open loop and using the MAP sensor instead of the MAF.

 

[Dr0]

So should I suspect a maf issue? I know how heatsoak feels and although it may contribute its not the underlying issue.

 

[2003.5_MSP]

So should I suspect a maf issue? I know how heatsoak feels and although it may contribute its not the underlying issue.

thats where im at right now... im suspecting my MAF/coilpacks, just waiting on money to confirm this

 

[hornsfan10609]

If the car runs better with the MAF unplugged your MAF is bad however when the car is in boost it ignores the maf signal anyway.

 

[2003.5_MSP]

If the car runs better with the MAF unplugged your MAF is bad however when the car is in boost it ignores the maf signal anyway.

So is there a way to check this? Could I start car and then go unplug my MAF, if it dies its not MAF..?

Also where can I get a complete set of coil packs for a decent price... thanks

 

[Sport23]

I will run with or without the MAF. If it runs better with the MAF then your MAF is bad (or needs to be cleaned.) Try rockauto for the coils.

 

[2003.5_MSP]

I will run with or without the MAF. If it runs better with the MAF then your MAF is bad (or needs to be cleaned.) Try rockauto for the coils.

Cool thanks

 

[2003.5_MSP]

As I was thinking about this more and more... If a wastegate is torn it would allow for over boosting, bc I sometimes get boost spikes of 9-10psi on stock tune with no piggy back tuner? I know there's a test to do to see if its bad, if I can blow threw with now pressure it's torn correct?

 

[Sport23]

Correct.