Thread: TPS reads fine with key on but not when running

The TPS sensor reads fine with the laptop connected. Shows Closed and .48v... Voltage rises, percentage goes up flag goes to OPEN etc... etc... all good.

BUT once the car is running and gets to about 120F, It still shows .48v at idle and closed throttle BUT when you rev it nothing happens... voltage and percentage does not increase???? which is causing fuel cut flag to trip at 2,000rpm because its not getting a TPS signal. Below 120F or so its fine when running.

I tried the board in another ecu and no difference..

Is my board shot or am I getting interference?

I kept my ecu grounds on the intake manifold just like before too. Tried and extra ground from battery to intake manifold also

bad tune?

I'm going to start but making a new tune from scratch

All of this started after installing new intake manifold/TB and new Q45 tps

Sounds like a bad TPS to me.

ok what is happening is tps read fines with car off and also does when running. The issue is my big 90mm throttle plate is barley moving when rev'd or when driving. This is causing my fuel cut kicking in issue! verified with laptop hooked up. The plate moves SO LITTLE when reving that the tps reading doesn't change LOL.

So what do all you guys with big throttle's

How can I disable this overrun fuel cut so I can drive my car. Plus the driveabilty is suffering because there is no change in TPS reading unless WOT??

TPS is brand new because I needed that older style one for my new 90mm universal TB.

Since you are on the super old version of the software, you will need to raise ALL of the FC tables to basically your rev limit or something the engine is not going to hit.

It has been a long time since I have even looked at that version of the software, but there should be 6 vertical FC tables that will need changed.

I guess I can't set these all to "0"?

I have even edited the XDF and set the "high" from 3,000rpm to 9,000rpm and the numbers get reverted back to 6,300rpm.. This is like the max its set for in the hardcode/programing. How can I set this to like over 8,300rpm (my current limit)

John, do you have any tips on setting the TPS up differently? So I can register a reading. Do we just suffer the driveabilty issues? I havn't done a maptrace yet but im sure its affecting where I am on the fuel and timing tables??

You would have control over it with the SA version, but with the older stuff it is hard coded and you won't be able to change it.

The max RPM for sure cut is likely 6300 or 6400 RPM, which isn't all that surprising as you shouldn't have to go that high.

Maybe @OnTheChip can chime in here.

Uncheck the "Use Low Range" and "Use High Range" check boxes, or set the ranges to 0 and 8000 in the XDF. Set the RPM values in the "Fuel Cut On MIN RPM..." tables very high, maybe 6000. Realize that this will put raw fuel in your exhaust manifold on overrun and back-fires and possible exhaust system damage can result. If the TPS is reading idle all the time, you still won't be able to tune much because it will used the idle timing tables. Drivability will also suffer from lack of accel enrichment. If the TPS reading changes only at WOT as you say, then that is the problem.

Ok thanks Dave. Fuel cut issues are gone. Ya if you just put put around, yes the tps barely registers but it does a bit. It does drive better for sure if you just accelerate a bit harder instead of easy.

I know tons of people use q45 (85mm) throttles without issue and some use 90mm or more. I hoped someone would share some tips ( if any ).

I'm sure the 90mm is best for max power but maybe 70 or 80mm should be used if drivin daily???

Thanks though


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I'm going to raise idle timing from about 17/1800rpm to 3000rpm in a linear fashion to help this just incase I'm driving real easy and still on the idle timing table. This was common to do anyways because with a chipped ecu when cold it usually hesitates some below 3000rpm and that was the fix. Not sure why? This is even on a stock TB and tps that's working correctly.


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