abnt89

iTrader: (1)

Hey guys I've searched but can't seem to find anything similar to what is happening to me. It's a fresh build on the factory turbo and so far the guy tuning it has it idling like a dream but anything after 29% throttle the IDC drops to zero. It also seems to want pedal assistance to aid in the startup. Now the car isn't in front of me as my friend has it at his shop since he has more room for it but this is stumping us and the tuner.

It has a new Walbro 450 that we tested and it is getting the correct voltage and everything was installed correctly. I relocated the battery to the trunk with some 2 gauge wire but I'm not sure if this could be causing my problems or not. It originally had some high impedance FIC injectors in it for startup and was accidentally started multiple times without the resistor box bypass installed so could have this damaged something in my ECU? We are going to try swapping the ECU's next week with one my friend has waiting to go into his Evo but I figured I would ask you guys in the meantime in case there is something we could be missing. Other than that nothing was touched on the fuel system or electrical side of things. Any help would be appreciated.

Thanks,
Anthony

CDrinkH2O

iTrader: (7)

Not removing the resistor pack will not have damaged anything.
What ROM are you tuning?
From your description it sounds like fuel cut. If it is a Tephra V7 ROM, check the Fuel Cut Multiplier and Fuel Cut Load x1 and x2 settings. It sounds like they may be set too low.

abnt89

iTrader: (1)

Appreciate the reply, I'm on the V7 ROM and I'll check the Fuel Cut Multiplier/Load as soon as I can get back to the car tomorrow hopefully.

I also forgot to mention that the car can barely get to 2500 rpms so I'm not sure what could be causing my issues right now.

4b11slayer

Is the car still on a maf?

abnt89

iTrader: (1)

No it's on Speed Density, forgot to add that.

4b11slayer

Fuel pressure test. Could be a fuel pump that isnt fully sealed and losing pressure in tank?

abnt89

iTrader: (1)

A couple of the bolts on the tank that hold the fuel pump housing in are broken but I've never had a problem with it before and you cant smell fuel in the car at all. The fuel pressure and voltage at the pump are both fine as well.

The car idles perfect but when you tap the throttle it goes lean as hell and if you keep your foot on the pedal it wants to die. I don't think it's the TPS either because it reads signal just fine on evosacan. Whoever tuned it before me though tried to adjust it to read 0% throttle but we fixed that right away. You can pretty much watch the IDC go to 0% as you give it throttle.

I keep thinking it must be a sensor or something in the tune because the symptoms don't really make me lean towards a faulty ECU. My friend does have a working OEM ECU that I could try swapping in if you guys think that could possibly rule some things out though.

EDIT: It's only throwing one minor code for air intake temp which I figured was because of the SD and scaling.

4b11slayer

By fuel pump losing pressure I meant the actual pump maybe be not fully seat up into the fuel pump hanger.

Im no tuning guru but maybe you should eliminate the iat code?

LetsGetThisDone

iTrader: (1)

Sounds like SD wasn't properly implemented in the tune. Find a new tuner.

RightSaid fred

The pump will be to big for the regulator.

You'll know this once you check the fuel pressure at idle with the vac line both on and off.


But with modified cars there's always more than just 1 problem.
You can't actually tune it until the pressure is stable.

abnt89

iTrader: (1)

I'll go ahead and clear the code but the pump fits perfect in the hanger right now. The factory sock at the bottom of the fuel pump sits perfectly on the bottom of the tank and if the pump wasn't seated I feel like the fuel pump hanger as a whole would not seat in the tank correctly especially since the 450 is longer than the 250 I previously had in there.

Before the engine was rebuilt the car ran fine though. It was a little rough and could have been dialed in a bit better but in no way was it acting like this and the tuner just started working off what was there from my understanding which should have been ok I would assume? Is there anything specific that I could look for that would cause an issue? The tuner is working on this on his side I just figured I would try to get some info on it as well from you guys.

The guys' shop that my Evo is at is actually running a 450 with 1650's on a stock fpr, fuel lines, and everything just like me. Is there something that you think could cause mine to be different? I'll have them check the fuel pressure though.

Thanks for all the replies guys.

4b11slayer

I have a wally 450 with 1450 injectors. Stock rail stock fpr stock lines. E85

RazorLab

iTrader: (8)

Don't pay attention to that Fred guy, he is just posting ignorance for post count. All his recent posts are fantasy land posts.

abnt89

iTrader: (1)

Yea that's what I was leaning towards too. I'm not really sure what to do at this point but I might try and swap ECU's just to rule that out at the least.

Does this all sound more like a tuning issue or a mechanical one like something being installed wrong or needing to be replaced?

LetsGetThisDone

iTrader: (1)

Go over the basic: Boost leak test. All sensors are plugged in. If you have an OMNI MAP sensor, replace it. They are known to go somewhat bad and cause issues, especially older ones.