Car goes lean sputters under any boost dsmlink v3 log included

[Joshky9]

The list of mods in my profile are accurate. Recently the car has not been able to go under any boost and immediately starts to lean out shown by aem wideband gauge and in the provided dsmlink log. The car also would not really go at all which we determined to be a bad CAS which we have since replaced. The car was at one point running great and boosting nicely until one day it just started leaning out under any boost. We have since checked/done:
-Boost Leaks
-Sent ecu back to ECMtuning which that have reported works perfectly.
-Compression
-TPS
-Replaced fuel pump
-Tested AFPR
-Swapped out coil, Ignition Control Module, Plugs and Wires.
-Swapped GM MAFs
-Tested injector resistor box
-Checked/replaced inline fuel filter
-Some others im sure but am frustrated now so I cant even recall half the other stuff we tried.
So if you would please look at the log, if any of you have had similar situations and have any advice at all I would greatly appreciated. Really miss boost on this car. I dont think the situation is completely related to tune of the car but I know we are not experts in that area but no matter how we adjust airflow sliders/fuel adjustments we still end up with this extremely lean condition as soon as the car sees any boost.

Thanks

Josh

 

[minimoose]

What kind of fuel pump are you running and fpr?

 

[Joshky9]

Walbro 255 LPH and Aeromotive AFPR. One other thing to mention was I bought a new coil pack from advance to test to see if that helped when we put it in it actually ran worse. The primary resistance was also somewhat out of spec similar to the ones that were in the car at ~1.2 ohms.

 

[minimoose]

What do you have the pressure set at for the fpr and what size injectors are you running. Have you changed the fuel filter in the bay and next to the tank?

 

[Joshky9]

37 psi with vac line disconnected I run FIC 650s. As far as the fuel filter I have an lines from the tank to rail and back and we have just replaced that fuel filter.

 

[minimoose]

Stock 450's on a manual run around 37. Im not sure what pressure the 650's are to be set at but I highly doubt its stock fuel pressure.

 

[Joshky9]

From what I have gathered FIC and many other injector companies flow rate their injectors at 43.5 PSI. I have tried this setting as well. With that said the DSMlink v3 allows you to dial in your fuel pressure injectors etc. My question is if my setup is reasonably dialed in so I can continue to search for other possible problems.

 

[Andranik]

hey dude im having the same problem when i start building boost my car starts to sputter for a bit. I think this is because of the O ring that goes on the nipple of the fuel pump. You can check by turning on the car and go out side look at the fuel pressure gauge it should be where ever u set it at 37 42 whatever, then go inside the car and shut the car off then come back and check the gauge again it should still read that same number u saw when the car was on. If not then more than likely that O ring is leaking and not hold the pressure. Hope this helps

 

[Joshky9]

Thanks for the reply's I should also explain a little more about my fuel system I have an fuel fittings and ss braided line from the tank to the rail and back. My setup is exactly the same as this high flow fuel setup that is described in this fuel tech article

http://www.dsmtuners.com/forums/articles-engine-fuel/254501-high-flow-fuel-set-up.html

 

[Imback]

How did you test your ARPR?

 

[Andranik]

okay i under stand but did you check to see if it is holding the pressure ? could have a tiny leak somewhere maybe where the walbro is connect to the an fitting with that hose just double check cause that was my problem

 

[Joshky9]

Well I wouldn't call what i did the most accurate way to test the AFPR but I have read in other posts some ways to check it out. I checked for gas or gas smell coming out of the vac line-none. I did check for air leaks in the adjustment screw, there was a leak and I did fix this with teflon tape. Also while the car was idling I fashioned air compressor fittings to pressurize the AFPR through the vac port in 5 psi increments up to 30 psi and fuel pressure did raise in a 1:1 ratio with pressure applied to the fpr vac port. I have heard that Aeromotive FPR do have issues with pressure draining back to 0 with a certain amount of time. Mine stays pressurized for approximately 10-15 minutes after I have stopped driving it and then drains back to 0. It did do this before I was having these issues so I am not really all that worried about it. It really feels like the car is missing, obviously its running lean but im not sure if its caused by the poor spark or an actual lack of fuel, or some sort of electrical component, bad ground etc just making something in the engine system not work properly. I am hoping someone with a fair amount of knowledge about the dsmlink will be able to read my log and see if i am missing something from the logs that would help solve my problem. Thanks everyone been so frustrated with this car.

 

[Imback]

Is there a reason half your sliders in maf comp are down? Your telling the ecu that there is less air coming in then there really is thus causing a lean condition.

 

[Joshky9]

I am using a gm 3" MAF with dsmlink connect cable. At those airflow numbers I had to calibrate the ecu to see less airflow because my lo fuel trim was very rich. I have adjusted the airflow settings a bit since the time of that log and my maf comp table looks more like this with still no change in how the car runs. I can adjust these airflow sliders all the way up and the car will still show lean when I start to get into the boost literally <5 PSI.

 

[Imback]

I had a friend who's cable went bad on him and caused similar problems. Are you running this in blow through?

 

[Joshky9]

Yes I have read about other cables going bad. Another thing I did that I forgot to mention in my earlier frustration was that I did send the ecmtuning stock maf to gm maf cable back to them they tested it said everything was in working order. Is there a way to check resistance, voltage, etc. that anyone knows of on this cable? Do my general MAF readings during my logs look all that out of the ordinary? I tried to look for some sort of crazyness in the maf readings and I really am not seeing anything that significant but like I said im not expert as far as tuning and this sort of thing goes. I can just search and read other posts somewhat well haha.

 

[Imback]

If you still have your stock maf i would throw it on and see if the problem is gone. This is why i was never a fan of the gm maf it's just another variable when things go wrong.

 

[doubleclutch99]

I had the exact same issue you are having now. i couldn't figure it out. my logger kept showing lean but i was sure it wasn't fuel related. why? because i have the exact same fuel setup that you have. and it was all new. so one day i hook the guage to the regulator and set it up so i could see it under boost . as soon as i took it for the first ride i had my answer . at 15 lbs of boost and 37 lbs of base fuel pres. it should of been 52 lbs of fuel pres. under full boost . right ? well i had 20 lbs of fuel pres. so the brand new walbro was junk. and the whole time my logger was slapping me in the face. it was a pretty humbling to say the least. so i looked at your log under the wot part and i see the same thing i had before .

Go to 764.084 sec in your log and you should be able to see the absence of an o2 signal under the wide open throttle. also your wideband shows really lean

 

[Joshky9]

Popped old MAF back on took it for a drive falls flat on its face still . Makes sense doubleclutch99 I just replaced that Walbro 255 from summit 3 weeks ago because we thought it was the fuel pump. I checked the voltage to the fuel pump while driving using my multi-meter and it stays around 12.5-13 volts. so you think trying to mount my fuel press gauge while driving is the best bet or just take the pump back to summit because it hasnt been 30 days yet. Thanks for the help.

 

[doubleclutch99]

I mounted it so i could verify what was going on because i was ready to set the car on fire and walk away. haha, but instead i made it a lesson learned and decided to help anyone i could, to not have the same problems i did. i really hope this helps

 

[Joshky9]

Now im really getting frustrated went to summit today got another fuel pump installed it boom same problem. Changed FPR back to stock to see if somehow that was the culprit still nothing. I did notice however when free revving in neutral i would see the fuel pressure dip down to 20 immediately so what are your thoughts now. Thanks for everyone's input this has been a crazy frustration

 

[doubleclutch99]

When you free rev, you are still in vacuum. so you won't see a rise in fuel pres. but i'd look at maybe a bad regulator or regulator fuel gage .

 

[Joshky9]

Thanks for the input on the vac during free rev but I still think when i free rev i get vac to go to almost -4 to 0 psi and I observed the fpr gauge go from 30 ish to 20 psi or less. It is one of those dreaded liquid filled gauges that people tend to dislike. My next plans are to get a ss braided line so i can accurately see the fuel pressure gauge while driving as well as possibly get another fuel pressure gauge. Also I looked for kinks in the system and there appear to be none. The fuel line from the pump is 8 an do you guys feel that is to large for this pump even though I have read many others using this size without issues. Im also not sure how a AFPR can fail without any leaks in the diaphragm thanks again for the input.

 

[doubleclutch99]

Also check the fitting that goes in the side of the regulator where the fuel line attaches. when mine was tight it bottomed out in the regulator and i couldnt hardly get any fuel pressure. i cut a half inch off of it and installed it back into the regulator and walla i had good fuel pressure. but when i rechecked the fuel pressure it was at like 75 psi because i removed the restriction . after that it was all good. hope this helps

 

[doubleclutch99]

Also on a side note 8an fuel line works fine . that's what i run on mine and no problems.