Just recently my turbo'd ecotec started leaning out. Running a T3 super 60 turbo, 36lb injectors and a BEGI FMU w/racetronix fuel pump. My AFR at WOT used to be a perfect 11.7 but just recently it started going to 13-15 at WOT. Could my FPR be bad and need a rebuild? I just put in the racetronix a few months ago so im hoping it isnt that. Any help would be greatly appreciated.
"You can only feed them semen for so long before their legs fall off."
When was the last time you changed your fuel filter? Also, have boost levels increased at all?
P&P Tuning
420.5whp / 359.8wtq
Just recently changed the fuel filter and boost has stayed a constant 9-10lbs. ALSO, twice now it has pinnned below 10AFR at idle. Could my FMU be jamming or something?
"You can only feed them semen for so long before their legs fall off."
Sounds like it could be your FMU but it could be a couple things. Check all of your vac lines and check out your fuel pressure. If you have access to hptuners what do your short term and long term fuel trims look like?
Do you have a fuel psi gauge? If so, has it chaged pressure? What are you running for pressure also? Its possible that your old fuel filter could have had some restriction in it and your tune was compensated for that....
P&P Tuning
420.5whp / 359.8wtq
@!#$ can the fmu and get a tune. an fmu is not a tune. your ecm doesnt know you have 36# injectors installed so your going to run rich at idle and at all non boosted rpm range. your ecm is trying to compensate by trying to bring the afr at 14.7.
An FMU is a mechanical tune. I actually dont run rich at idle. Perfect 14.3-15.4. The ECM has never interfeered at all with my turbo setup. Rarely throw any codes and when I do it's a P0420 which is no biggy at all. But Im betting the FMU needs a rebuild. I'm going to get gauge for the "in" side of the FMU tomorrow and slap it on. Let you guys no what I see.
"You can only feed them semen for so long before their legs fall off."
Senorguitar wrote:An FMU is a mechanical tune.
Bullsh!t..... Its a hack/half@ss way of doing things, especially when better options are available.....
P&P Tuning
420.5whp / 359.8wtq
QWK LN2 (needs an @ss whoopin) wrote:Senorguitar wrote:An FMU is a mechanical tune.
Bullsh!t..... Its a hack/half@ss way of doing things, especially when better options are available.....
I didnt say it was a great tune, but it's a tune none the less. How crap was done before HP/computer tuning. Cheap, effective and provides great results.
"You can only feed them semen for so long before their legs fall off."
QWK LN2 (needs an @ss whoopin) wrote:Senorguitar wrote:An FMU is a mechanical tune.
Bullsh!t..... Its a hack/half@ss way of doing things, especially when better options are available.....
Hey now... Come on man
I'm running one but it's a little different style.
QWK LN2 (needs an @ss whoopin) wrote:Senorguitar wrote:An FMU is a mechanical tune.
Bullsh!t..... Its a hack/half@ss way of doing things, especially when better options are available.....
Don't let Hahn hear you say that
...and in all fairness, so is Alpha-N
I have no signiture
Whalesac wrote:QWK LN2 (needs an @ss whoopin) wrote:Senorguitar wrote:An FMU is a mechanical tune.
Bullsh!t..... Its a hack/half@ss way of doing things, especially when better options are available.....
Don't let Hahn hear you say that
...and in all fairness, so is Alpha-N
(insert Port Fueler add here......
) Using an FMU does not mean you have a "tune"..... Granted, Alpha-N is not the most "ideal" way of doing things either, but it does work. All an FMU is is doing is raising the fuel pressure (as stated before, not a "tune") Atleast by "tuning" (IE: commanding/changing PCM parameters), you can make the proper changes to make it "safe".
Let me rephrase that, "safe" if you know what your doing.....
Edited 1 time(s). Last edited Tuesday, November 23, 2010 9:31 AM
P&P Tuning
420.5whp / 359.8wtq
Senorguitar wrote:An FMU is a mechanical tune. I actually dont run rich at idle. Perfect 14.3-15.4. The ECM has never interfeered at all with my turbo setup. Rarely throw any codes and when I do it's a P0420 which is no biggy at all. But Im betting the FMU needs a rebuild. I'm going to get gauge for the "in" side of the FMU tomorrow and slap it on. Let you guys no what I see.
the ecm is changing its long term fuel trim to compensate for the larger injectors. the ecm can only change so much. thats were a tune comes into play. a tune involves adjusting fuel and timing maps to compensate for extra air entering the engine weather its a n/a engine or a boosted engine. a fmu is not going to be able to do this therefore it is not a tune. an engine requires the correct amount of fuel and timing at different engine loads and speeds. YOU WILL MAKE MORE POWER AND IT WILL BE MORE RELIABLE WITH A TUNE.
Come on now guys. It is law that a Ecotec can be ran at 14:7:1 AFR's in boost and have no knock and be good.
FU Tuning
JOE L wrote:Senorguitar wrote:An FMU is a mechanical tune. I actually dont run rich at idle. Perfect 14.3-15.4. The ECM has never interfeered at all with my turbo setup. Rarely throw any codes and when I do it's a P0420 which is no biggy at all. But Im betting the FMU needs a rebuild. I'm going to get gauge for the "in" side of the FMU tomorrow and slap it on. Let you guys no what I see.
the ecm is changing its long term fuel trim to compensate for the larger injectors. the ecm can only change so much. thats were a tune comes into play. a tune involves adjusting fuel and timing maps to compensate for extra air entering the engine weather its a n/a engine or a boosted engine. a fmu is not going to be able to do this therefore it is not a tune. an engine requires the correct amount of fuel and timing at different engine loads and speeds. YOU WILL MAKE MORE POWER AND IT WILL BE MORE RELIABLE WITH A TUNE.
tuning coupled with an FMU is the only way I'd do a turbo setup with HPT.
alpha-n does not reference MAP for fueling tables... so partial boost and changing load will constantly throw the tune off.
speed density is better, but that isn't what we have.
HPT alone with a turbo? no.
FMU alone with a turbo? no.
tuning the alpha-n tables with HPT AND using an FMU as the actual reference for boost is better.
the only way to truly get a tune is to switch to something that will reference manifold pressure for fueling... easiest way is a megasquirt system controlling the fueling (true speed-density)
