Im having a strange issue i've had for quite some time. During a 3-4-5th gear pull my tps voltage will suddenly drop for a split second at high revs (7-7500ish) causing a lean condition and a slight knock. Obviously this is concerning.
Anyone had anything similar? TPS itself has been changed and calibrated several times.

Car is approx 600hp B-series.

Thanks

 

Is this consistent or occasional?

 

Consistent I’d say but certainly not every single pull 😬

 

So then, conditional. Hmmmm..

 

well its hard to say because i haven't logged every run over the past few weeks, but last night my tuner was with me and it happened every run. Mostly 5th but sometimes 4th too.

 

What tps you using? Blox, by chance?

 

erm, no, currently a Tegiwa sensor. Have used BLOX in the past and that died.

 

Lol! Kinda why I asked. I had an identical issue. Was using a Blox TPS.. Swapped to a Dorman and the issue resolved.

 

Ive been through at least 4 now. I swear they all come from the same factory. They are rubbish. I don't know why there isn't a hall effect sensor conversion for these.

What problems did you have exactly?

 

I was getting a voltage drop at WOT occasionally. About every other pull or so.

 

oh wow. so exactly the same then. What throttle body were you running? I have just ordered a Dorman TPS so i'll try with that.

 

Skunk2 70mm TB. It wasn't every pull, but it was always WOT. Usually around 7k rpm too. It would go from 100% to about 91% +/-. Check your live data first, manual sweep it by hand, see if you get 100% that way. If so, then check it inside the vehicle and mash the pedal to the floor. If you get 100% on hand sweep and not on pedal, adjust your throttle cable bracket. If you dont get 100% on manual sweep, it's bound to be the TPS or stop screw. If the stop screw is set good, the tps is the top suspect.

 

The TPS was setup perfectly. Voltage bang on, and on hondata it was roughly 4%-100% iirc. This is ALSO on a Skunk2 70mm Alpha TB. Part of me thinks its something to do with that tbh. Mine drops to around 42% from 100% on a WOT pull but does vary.

 

So voltage STARTS at 4%?

 

I actually cant remember tbh. It could be 1%. When i calibrated it it was perfect 0.45 - 4.63v on the meter

 

Ah, right on. So at 1%, it's jumping to about .47-.49 then.
Check the throttle cable bracket? Make sure it's not too tight or too loose?

 

in what way could that cause the problem im having though?

 

If the cable is too tight, it will cause excess tension on the throttle plate, in turn, causing the TPS to get a false throttle reading; i.e. higher voltage as if the accelerator were being pressed. Too loose will keep the plate from opening fully at times when you're actually pressing the pedal. Check the screws holding the tps to the TB also. If they're loose, that will cause the tps to shift as it is doing its thing, making it almost necessary to have to calibrate it over and over and over.

 

Have you tried a OEM TPS?

 

impossible to get hold of.

 

No but the fault would be apparent all of the time if that were the case. It's definitely not a case of that.

 

Not necessarily. The loose bracket came up recently for me. Noticed I had the issue again at WOT. Thought I'd need another damn tps. Turns out my throttle bracket was loose. Lol!

 

Bumping this up. Car is back out again with slightly different setup. Circa 700hp. EXACT SAME ISSUE STILL.
Always seems to be 4th gear at around 7500-8000rpm drops from 101% to 60% sometimes 80%.
This is really ******* annoying tbh. Guess i'll have to try a new TB?
Pics attached.

 

Unsure, my dude.. Seem to have exhausted my possibilities, and with no possible way to get an OEM TPS, **shrug** No other feasible suggestion except; buy a new TPS, or new TB. I highly doubt this to be a TB issue but, stranger things have happened..

 

Ive been through at least 5 TPS's now, including the one you recommended. All seem fine to begin with.