lean sputtering/missing

[mr2turbo]

When driving with less than 10 in hg of vacuum car is fine. Once accelerating and more than 10lbs of vacuum the car will start to lean out and sputter shortly after. Doesnt even have to hit boost for the car to sputter. The car doesnt even seem to add fuel when accelerating just starts to go lean. When I floor it in neutral it wont go past 4 or 5k and will just sputter. It's not a loud backfiring kind of dull sputter


mods:
6 bolt swap
2g ecu with dsmlink
780cc injectors
walbro 255
50-trim and supporting mods.


I've done a boost leak test, its good
New spark plugs, gapped at .26
spark plug wires are good
New walbro 255 with sock filter
pulled the fuel filter, cleaned it off but it was fine either way
tryed another ecu, no luck


I should mention that my voltage regulator went out recently, the car was running 17v but it still ran good, replaced the alternator, and this started again. If anybody has any suggestions or something to check lmk

 

[talondave]

Any way you could get a hold of another CAS? It could be faulty!! Worth a try!!

 

[TurboJimbo]

Make sure the TPS and MAF are plugged in all the way...those sound like symptons of one of these being unplugged or not working correctly...car will run fine if you baby it but once you give it just alittle throttle thats when it sputters

Also check your ignition timing. good luck

 

[Mindslayer]

Too much fuel, try lowering your FP. What are your trims doing?

 

[mr2turbo]

fuel pressure at idle is 43 psi, I have an adjustable fpr, I raised it to 65 psi to just make sure it can go that, I unplugged the mas and it ran richer but for the most part it runs the same

 

[justin90gsx]

this exact same thing happened to my car, tried everything above and what you have,
and it was my coil pack

 

[mr2turbo]

ltft lo is around -5% and ltft mid is usually around zero, im still gonna have to check out the coil.

 

[mr2turbo]

coils good, any other ideas?

 

[mr2turbo]

tried a coil on plug setup didnt change anything, tried out another maf, it actually started to pull then broke up at 4500 rpm but it still ran better with the other maf, which confuses me, does anyone know exactly what the transistor does?

 

[TSiAWD666]

Last time this happened to me I realized my fpr's boost line wasn't connected. Found the fellow that had been working on my car left it disconnected. I.e. fuel pressure wasn't rising with boost.

 

[mr2turbo]

fpr vacuum line is connected, also i've tried to change settings on dsmlink and it doesnt even effect the way the car runs, also tried another ecu

 

[mr2turbo]

How can I tell if fuel pressure is rising from the cabin?

 

[mr2turbo]

anybody know how i can do that?

 

[mr2turbo]

other ideas?

 

[BIRDCLAWTSi]

you can tape a fuel pressure gauge to your windshield.

 

[BIRDCLAWTSi]

check the connector on the maf. sometimes corrosion will get in there. it sound like you have a vacuum leak. pull a couple spark pugs and see if they are all black. what is your front o2 doing while you are cruising/accelerating? do you have a cat? no exhaust restrictions right?

 

[BIRDCLAWTSi]

sorry man, one more thing... do a compression test.

 

[NOSLO2PT0]

How can I tell if fuel pressure is rising from the cabin?

Turn the fuel pump on via DSMLink, then hook up an air compressor with 20psi of air coming out to the boost source on the FPR (small nipple on the hat of the FPR) . Hit the trigger on the airgun. Fuel should increase 20psi. Very possible you have the lines to the FPR backwards. Local just did this and had exact same problems. Bottom port should go to fuel return line. Side port goes to the driv. side of fuel rail.

 

[MakeIt2BreakIt]

+1 his idea ^

 

[mr2turbo]

okay, I had fuel pressure at 45 psi, I set the compressor to 25 psi, and my fuel pressure wont go above about 63 psi. I tried to manually adjust above 63 but it cant go higher. So I turned the fuel pressure down 5 psi and took it for a spin and the car ran a lot better, sometime this week when its not raining im gonna have to figure out why it wont got higher. My first guess is fuel filter, if thats not it, Then im thinking fuel pump outlet where it meets the assembly. What are some other possibilies?

 

[mr2turbo]

I took the filter element out of my fuel filter and turned on the fuel pump and could not go past 63 psi.
So I took out the fuel pump assembly and inspected threw it back it and it wouldnt go past 60 psi this time. I have boost set at 15 psi and fuel pressure set at 45 psi with the line disconnected. So What else could be limiting my fuel pressure?

 

[dented_coffee]

I took the filter element out of my fuel filter and turned on the fuel pump and could not go past 63 psi.
So I took out the fuel pump assembly and inspected threw it back it and it wouldnt go past 60 psi this time. I have boost set at 15 psi and fuel pressure set at 45 psi with the line disconnected. So What else could be limiting my fuel pressure?

when the lines were installed (stainless steel braided) maybe they got a kink in it from it getting bent to install. and maybe your injectors are bad. they should be arround 4.5 ohms on a multi meter. if not bad maybe just plugged.