Chrome user having major issues and out of ideas!

[twinspoolin94]

I just got my car back from the dyno and I am having some major issues. Here is what has been done to the car.
Montero maf, k & n filter, dn pre intake pipes, evo x bov and map sensor, 15g turbos, turbo back exhaust with no cats, greddy fmic, vac hose redux with all emissions deleted, egr blockoff, jester ecu running chrome. Fuel system is aem 340 hotwired, stm tank to rail kit, low miles on fuel lab fuel filter, 850 fic injectors, fuel rail loop, STOCK FPR.
During my first dyno session 2 weeks ago we determined that the car was not holding fuel pressure in the upper rpms. At the time I was running a walbro 255 unhotwired. They tried to hotwire the walbro but almost the same result. We decided that I needed a new fuel pump so we put in the aem 340 and they rigged up a hotwire for testing. The car held pressure fine. It was late so we decided to have the car tuned later on and I was given the car back with the aem pump installed but not hotwired. I was also on 450cc injectors at the time.
The next week I ordered a hotwire kit and installed it. Immediately I had problems with the car going super lean during low throttle. I could give it some gas and recover from the condition. It only did it bad immediately after the hotwire and it was fine the rest of the week of driving and showed up once early one morning. The next week I received my 850 injectors and installed them. The car ran rough which I expected and the morning after install I was due to get the car redynoed. The drive down was rough and the car would almost stall at every light.
Immediately they ran into issues on the dyno. Car would not idle and would not accept changes flashed to it. After a full day of trying I called my wife to pick me up and left the car for them to fix. I was informed early this week that I had a bad coolant sensor, o2 sensor, and that they replaced the IAC but the IAC they took out was still good. I opted to leave the new IAC in because it was cheap and its a common issue. I was informed that everything was good and that the car made abot 420 whp on the rollers. Spoke with the manager and he told me that the lows could be more perfect but the car was good to be picked up. After getting the car back on low throttle the car is just as bad as when I brought it to them if not worse. Idle is all over the place as are the afrs. I tried using the stock maf and I checked all the wiring with the hotwire and it good. Is there something in chrome that I could be missing? FPR overrun? If anyone has any ideas please help a brother out so I can get this car right! Thanks!

[Greg E]

How do you have the fuel pressure gauge hooked up to the fuel line?

[twinspoolin94]

How do you have the fuel pressure gauge hooked up to the fuel line?

Greg thank god you are here! So I had the gauge hooked up at the rail but the elbow cracked when they unscrewed it so it just has a plug there while I track down a elbow for it. I am waiting for a call back and will request the logs to determine the fuel pressure. I know it was high and overrunning the FPR when I brought it to them the 2nd time, but I assumed they tuned it out

[twinspoolin94]

Also checked the peripherials and the dual narrowband function was disabled, I am waiting for an explanation on that as well

[twinspoolin94]

only a few thousand miles and I only run 93, also car has only 82k

[Greg E]

I Is there something in chrome that I could be missing? FPR overrun? If anyone has any ideas please help a brother out so I can get this car right! Thanks!

Let me answer this question for you at least... The answer is no. Chrome has nothing to do with fuel pressure once you Hotwire the pump. In fact, it should still run like stock even in "single narrowband mode". Jason Y drove his 99 like that for a year with no issues.

FPR over run would only cause a rich condition at idle. Once you get a little bit more air moving, it goes away completely as you're spraying more gas into the motor instead of holding into the rails.

[twinspoolin94]

Ok, that's good to know. could the jumpers on the ecu for the o2 sensors be backwards? I read a thread awhile back about one of jesters ecu's having this issue?

[Greg E]

That's only an issue if you order the wrong one for your car. If that were the case, when you switch back to dual narrowband mode, the sensors will read opposite lock.

[twinspoolin94]

my lows are maxed at -12.5

[twinspoolin94]

Another thing I am noticing is the car idles decently stable with the narrowbands turned back on, but when I touch the gas and let off it never trips the idle switch and it stays a few hundred rpms higher.