TTA breaking up above 2700 rpm under load

[UNGN]

I'm putting my TTA back together for my son to drive, and it starts, runs, idles and drive around town fine, but breaks up and bucks when you try to accelerate over 2700 RPM. Needless to say it doesn't make any boost.

Here is what it isn't:

Chip, ECM, Fuel Pump (Ractetronix hotwired GS340), Fuel Pressure, injectors, MAF, Plugs, Plug Wires because all of these are new or have been swapped with known good with no change. Motor has 72K miles and the oil is clean.

I've unplugged the Cam sensor, went for a drive and nothing changed, it still breaks up when the tach gets to 2700 rpm.

The Coil measures 13.7, 13.7 and 14.2 K Ohms.

Next I'm going to swap the coil/Module from T-type to see if this changes anything. I don't have any scan data because I can't find my Turbolink cable.

Anyone have any other ideas what it might be? Completely different 92 octane chips/ecms/injectors (55lb and stock) gave the same result so it seems to be ignition related.

 

[whitehot1]

Check the ground wires on the back of the head. Make sure the ring terminals are tight and that the wires are not broken or have been damaged.

 

[JOHNDEEREGN]

Great to see you around, is this for your son that used to do the power wheels? I remember seeing that somewhere a LONG time ago. You had a 2+2 that ran in Arnold Ne at Sandhills IIRC?

I just live 2 hrs. south of Arnold. Sorry off topic but one of the experts will hook you right up. My son is going to college this year and he is about your sons age, time flies

Ty

 

[UNGN]

I will check the grounds. I swapped coil packs and results were identical - Right at 2500-2700 RPM it bucks snorts.

Ty,

Yes, Wil just turned 16 and loves the TTA and thinks T-Tops are one of mankinds greatest inventions. It was just collecting dust in the garage, so there is no reason it shouldn't be on the road. 25 year old cars and older are emission exempt in TX and the inspection was only $4, so it is cheap transportation.

 

[turbo89]

I will check the grounds. I swapped coil packs and results were identical - Right at 2500-2700 RPM it bucks snorts.

Ty,

Yes, Wil just turned 16 and loves the TTA and thinks T-Tops are one of mankinds greatest inventions. It was just collecting dust in the garage, so there is no reason it shouldn't be on the road. 25 year old cars and older are emission exempt in TX and the inspection was only $4, so it is cheap transportation.

check the crank sensor .. easy check and do exactly as you described

 

[UNGN]

check the crank sensor .. easy check and do exactly as you described

There is some ticking from the front of the motor. I will give that a shot.

 

[UNGN]

Swapped Crank sensors and now it builds boost to 10psi (though not really accelerating like 10 psi of boost) and doesn't breakup until 3500 RPM and it finally threw a code.

Code 32 EGR. Could this be the issue all along?

 

[UNGN]

I swapped EGR Solenoids... still shuts down at 3500 RPM.

going to troubleshoot the rest of the EGR system.

 

[UNGN]

I am back to diagnosing this. Car still runs like crap under boost.

Waiting for my Turbolink cable to arrive tried Bluetooth adapter from 1320electornics and their ALDL scan on my phone. It showed knock retard degrees at 8 degrees under 3 lbs of boost with the car bucking. Not sure how their ALDL app measures knock though. Its about 16 degrees at Idle with a Thrasher street Chip. I wouldn't think there should be any knock at 3 psi of boost with a thrasher 92 chip.

O2's and MAF numbers looked good

I know how to use turbolink. I'm still learning this App stuff.

 

[whitehot1]

Do you have another chip for your injectors that you can swap out for the Thrasher chip?

 

[UNGN]

Do you have another chip for your injectors that you can swap out for the Thrasher chip?

It did exactly the same (Breaking up at 2700 RPM) with 55lb injectors and a TT 92 street chip w/ modified ECM as it is currently doing with stock injectors, Stock ECM and Thrasher 92 chip.

 

[Mr.Spool]

Fuel pressure rising 1to1 with boost?do you have a wideband?my other thought would be maf I know you stated you felt it wasn't but I have seen what you are describing and the maf/wiring was the issue.

 

[UNGN]

Boosting on the driveway against the brake @ 3 psi, the Fuel pressure is is solid and increases with boost, but the RPM's are less than 2500. The badness only seems to happen above 2700 RPM.

The car has a brand new Racetronix pump with a Racetronix hotwire. I'm going to put in a new fuel tank this weekend (the filler neck on the old one leaks) and will check the pump for issues, but it should be giving enough fuel for 3 psi of boost @ 2700 RPM.

I should get good Turbolink data later this week.

 

[BMR]

I see you stated the plugs are new. Did you possibly gap them too wide, or forget to gap them? Is it clean without load/boost?

 

[UNGN]

I'm going to swap knock sensors. Something is making the motor knock at idle or the knock sensor is bad.

The motor revs fine to 5K with no load, but chokes under load trying to accelerate over 2700 RPM. If the computer is pulling timing from false knock, maybe that is keeping it from reving over 2.7K?

 

[UNGN]

I seem to have found the problem. I bought the car 10 years ago it had a racetronix p&p hot wire kit installed. The previous owner must have thought he wouldn't need a new pump (and the hassle of changing it on a tta) if he hot wired the stocker. Car sat in my garage for 10 years until last month when we got it running and ran into issues.

The fuel gage didn't work after a new pump, tank and sending unit, so yesterday I bypassed the hot wire kit and plugged back into the factory wiring and the car runs like new and now the fuel gage works.

Close examination of the hot wire kit shows a female pin where a male pin should be and the incidental girl on girl contact wouldn't support enough amps to keep the pump running above 3 psi.

 

[Mr.Spool]

Good work,the wiring stuff is always a good time.

 

[UNGN]

Yeah, I'm going to eventual go through the racetronix harness swap out the wrong pin and get it to work, but I've wire tied it out of the way for now. It is usually something you don't expect that turns out to be the problem.

Car runs great now and my son thinks its "faster" than my '13 5.0. Of course it isn't with a street chip and the cat in place, but he doesn't know that the fun is all over when the car shifts into 3rd, and won't find out in our town of speed traps and unmarked cars and SUV's.

It proves that torque "feels" faster than HP on the street. His friends were impressed with 1980's tech, too.