Hi guys. I really need help please.

So my car has been at the shop for bloody ages. Boosted VQ.

Shop made a bugger up and fixed under warranty.

But now there a TPS fault that comes up randomly. Car just won’t Rev at all. Still in the shops hands. I haven’t t gotten the car back yet.

They’ve replaced throttle body, checked plug and play harness from the ECU (I’m running MaxxECU) checked sensors etc. but same issue.

They say that they reckon the main harness is brittle with the heat from from the turbo kit and need to pull it completely and rebuild the entire harness. I’ve put shed loads into the car and this is just more money.

anyone have an idea on what else could be the cause?

is this a viable problem with the harness? Or are they pulling at straws?

 

I'll bite. Most of the times I see building a harness it's for an engine swap. The TPS has to be programmed "pedal dance" to work. If you're getting a TPS code, it should be replaced, no questions.
Back to the harnesses- brittle is an interesting word service people use because if it's brittle, it's likely to break. Let's use a different word to measure whether the wiring can properly carry electricity - Continuity. (Taking electricity from one place to another reliably). Testing for continuity is very easy. If you see vinyl cracking on lines or random sparking then yes, it's time to correct it. I'd ask to watch 5 minutes of continuity testing after replacing the TPS if it still has problems. I've also seen people with intermittent problem recheck ground locations with good results. Gl!

 

I would (assumingi it’s an option) put a new OEM harness in the car and get back to square one.

I dont know why the OEM harness is so finicky but it is.

 

thanks very much. Appreciate this. I would assume they should have tried the relearn procedure. But who knows. Will give them a shout to confirm.

 

thanks man. I’ve asked for a harness if one is available, I have a stand-alone ecu, I know there are RevUp harnesses available, could these be used? I know the VVT on the exh will not be used. But would this cause any other issues? Or will it strictly need to be the DE harness?

 

If they’re suspicious of the harness it would be terribly easy to simply run an overlay but route it away from the heat of the turbo. There’s like 6 wires to run max, so it would take less than 5 hours I would say, since you really just need to piggyback the wires to create a less vulnerable path.