User 52121

Ok that makes 3 board "experts" stating a funky TPS. (2bridges, CPR, and John @ Vitesse.)

I guess I'll cough up the $130 and order a new one.

My butt hurts after working on this car.

fast951

So far the only things we know for sure:
- Engine runs lean when you go WOT.
- Your DME + chip/board, KLR and MAF performed fine on my personal car.
- Before spending the $ on a new TPS. Let's see how the injectors perform.

tjbreen

Use an analog meter to test your TPS. I noticed that any jumps in sensitivity were hard to see on a digial scale. I even melted the cover of one trying to simulate an over heated unit but it was fine.

I would be happy to send you the slightly melted, but fully functional TPS unit for testing on your car.

fast951

Injectors checked out fine. So far MAF, DME, KLR, chip/board and injectors all checked out fine on my personal car.

User 52121

Alright. Brand spankin' new $150 (after tax) TPS installed.

Now just waiting for UPS to bring my stuff back.

I hope it works.

User 52121

Alright. Got parts back. Installed. Made sure all hose clamps, connections, etc. are good. New TPS installed yesterday. As we see from previous posts, MAF, DME, KLR, and injectors all run 100% beautiful on another car. Installed everything back in mine tonight and...

No change.

Removed injector resistors. (Just stabbing in the dark at this point.)

No change.

I added 2 massive ground straps (1" wide braided flat wire) from the battery to the fuel rail, and from the fuel rail to the MAF. I also cleaned all the grounds a few months ago and already have an extra ground wire running from the body to the valve cover.

Adding the two massive ground straps? No change.

So far I've wasted an extra $500 or so in parts at this thing trying to solve this issue (TPS, fuel pump, regulator, filter, plugs and wires) plus ~$150 shipping stuff back and forth to Georgia and I already splurged on this stuff to begin with.

Right now I'm 50/50 at fire-sale'ing all this stuff and putting it back the way it was, and 50/50 at seeing if a buddy of mine (who lives in Atlanta) will put up with me for a few nights so maybe I can sweet-talk a local expert down there into looking at this thing personally. Though that will involve spending MORE money and I don't think I'm game to do that either (at least at this exact moment.)

Or maybe just offer this thing up to the first $13k and go buy a Boxster.

Any other ideas? What else would cause this thing to run lean when I hit WOT? Lean enough to where I can feel a sharp stumble right as I hit WOT unless I have the DME on FQS 3?

I just about give up. I just want my car back the way it was. I'm sorry I ever messed with it. Ultimate buyer's remorse that's for sure. I already missed both an autocross and a PCA rallye because I had the bright idea to try to make it better.

*sigh*

User 52121

Alright. Somewhat clearer head this morning.

Plan is to start removing stuff one at a time. Depending on the wife's plans, I'll start removing all the PB, MAP sensor, and boost solenoid stuff tonight, and make sure the harness is exactly the way it was before I started.

If that doesn't kick it, then the next layer of stuff comes out (chip, MAF, injectors, FPR) and it goes back to stock until I can figure out WTF is going on here.

Tom M'Guinn

Have you confirmed the TPS signal is making it all the way to the connectors at the DME/KLR? Could be a break in the harness... Just pull off the connectors at the TPS and in the footwell, and make sure all TPS lines have continuity all the way across. Also check that none are cross-connected or grounded.

Edit: looks like maybe you already did this? if so, how are you determining that it's lean? Do you have a wideband?

xsboost90

we've been having a similar problem on Sam's car. It only does it sometimes though, but it leans out usually in WOT. The voltage to the pump will drop from 12v to 10v or so when the symptom shows up. Still havent figured it out yet. Even ran an extra wire from the DME relay to the pump in case it was shorted and no go.

User 52121

@ Tom - yes, TPS signals were tested @ DME.

As for resolution... it was to remove the Vitesse stuff.

I backed out everything, one step at a time. Piggyback wiring, MAP sensor wiring, reconnected all the DME wiring that was cut, etc. I tested and drove the car with each step to try to identify the culprit.

Ultimately I wound up pulling everything. Got down to just the MAF, chip, injectors, and 3 bar and the problem still existed. Put the Welt chip back in, stock AFM, stock injectors, stock FPR... car is immediately back to running like a champ. No stumbling, no lean condition (O2 sensor pulls ~.90-.91v at WOT.) Car feels smoother and stronger with part throttle acceleration than it did before.

Not sure what else to say. No other changes. My stock stuff, car runs perfectly fine. Install MAF, chip, injectors, and injector resistors... car runs like ***. Remove MAF, chip, injectors, injector resistors... car is back to running perfectly fine. At this point, I'm done - this is not what was expected.

Working out details of a return and refund with John now. He has been very accomodating throughout the ordeal. No doubt he has a genuine interest in seeing his customers happy. It's unfortunate I couldn't get his stuff to work, I know he's had hundreds+ of successful customers, and I was looking forward to experiencing what all the hype about his stuff is. But at this point, I am done - it obviously just doesn't work with my application.

For now I am closing this thread as the issue is just about closed. John and I are working out the finality of the deal in private. Again - John has been helpful and I wouldn't hesitate to buy something from him again.

Thanks to everybody who tried to help.