Supra lacks power after build-up

[90supraturbo]

Hi all,
I had my engine rebuilt and did a build up in the process. When running the car at low speed without boost the engine itself feels strong, but under load when she is boosting the turbo spools and sounds amazing and the car SOUNDS like it is responding but there is just a feeling of a lack of power. Maybe like she is bogging down...

When I did the upgrade I moved to a Spearco FMIC with 2.5" hardpipes but I'm still running the 440cc injectors and OE AFM... I'm wondering if the larger pipes could be causing the car to think there's more air going into it then there really is since it needs to bring the volume of the pipes to pressure before it reaches the intake and this is causing the car to run rich and bog... Gas mileage has been horrendous as well.

Please let me know any thoughts you all have.

Thanks,
Trevor

 

[KTM530]

Any codes?
what does your build consist of?

 

[IndigoMKII]

First, since you changed your pipes have you done a boost leak test first? I bet you've got a leak since you changed pipes. Changing the piping size won't confuse the ecu as its still seeing the same air the AFM is measuring but having a leak in the system will cause the ecu to add fuel that the AFM told it is in the system that isn't there.

 

[90supraturbo]

I'm getting a code 51 because the TPS is still out of alignment. Haven't had time to mess with it yet.

I suppose it could be a boost leak but it just doesn't behave like that's the problem. I turned off my boost controller and it'll pull 8 psi but still lugs... crank it up to 12 psi and it hits fuel cut right on cue at 11.5psi. (Boost gauge supply line comes off the back of the intake manfold) Wouldn't it hit fuel cut sooner if it was a boost leak?

I was hoping to avoid having to pressure test everything and have to pull hoses back off... but I may have to if I don't find a solution soon.

 

[Warlock1]

A code 51 will throw everything off including timing, which could be the problem. Its probably just dumping a lot of fuel which would explain the bad mileage and lack of power.

 

[90supraturbo]

Thanks everyone. The TPS was out of alignment which had caused the car to advance the timing significantly so even though it would show 10* when I timed it, it was actually not. Once TPS was aligned, I cleared the code and timed her up... running perfectly now.

I appreciate the advice. I've owned Supras since '98 and never had an issue with the TPS before. Of course this was the first time I'd taken it off completely also in order to clean everything up.

 

[Warlock1]

Awesome always glad to help out any supra owner especially the AZ owners..haha represent