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Thread: TPS sensor issues, fed up - Can i run without it? Options??

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2015-10-07 23:22:50
TPS sensor issues, fed up - Can i run without it? Options??
Dave/John or anyone else.

please read

I've been having some on and off TPS issues since I put on my Doug Fab intake manifold and 90mm throttle body. As of lately, the TPS has total failed

What a pain running a 90mm TB! (TPS issues)

I don't have the NEMU nismotronic so I can not run MAP (not sure if this would help my issue) I'm using tunercode with basic board.
I have had a bunch of driveabilty issues with this massive TB (caused by TPS). Normally as you drive the throttle opens and closes up to 50%. With a BIG 90mm TB my throttle only moves like 20% to do the same now. So I'm always into
"FUEL CUT" which I solved for now. Besides that I don't really get much accel/tps enrichment because the TB doesn't open much now while I drive it (unless WOT)

I've messed with this and that and have made the issues better but driveability is still a bit off from the stock sized TB and TPS

ANYWAYS.. TPS has totally shit the bed now. It was running like TRASH. I unplugged it and the car has worked the best it ever has in a few months :???:
What can I do, or should I do?

I'm not going to make any less power. Timing map is still used and i'd only be missing the Alpha/N feature from the Fuel Map right? No biggie, seemed to cause more issues then help. Car isn't running lean when I get on it btw

What about idle? I can just make sure I'm at 15 on the main timing map at idle, to match ignition timing can't I?

I wont be on TPS CLOSED IDLE TIMING but that's not a big deal is it?? I'll just do what I said above^

I don't use the IACV with this manifold just the valve under the intake manifold BTW! Just a note!

IDLE ADVANCE/RETARD will be disabled right? But I don't even use the IACV and have the TB screw set to 1000rpm and is fine HOT/COLD... no stalling or anything. I had previously set both idle advance/retard to zero because I have big CAMS.The car starts up fine cold or hot even here on the east coast

So should I buy a new one or leave it unplugged?

Is there anything in the tune I can change to help if I leave this unplugged or even if I buy a new one? This motor is n/a and will not see a turbo.


Last edited by Haulin200sx on 2015-10-07 at 23-26-59.
2015-10-08 05:04:22
One of the things you tried I assume was making the TPS read WOT (+4.0V?) when the throttle was really only open 40% or so? Yet still reading closed (+0.45V?) when the throttle is closed...
Maybe by adjusting the TPS in combination with a resistor on the low voltage side? Or some such nonsense to let the ECU know how much flow you're experiencing during small throttle changes...
2015-10-08 14:26:32
I suggest you upgrade to the NEMU NismotronicSA system as it has all of the parameters you need to tune with the larger TB. Not all of those parameters are supported with what you have.
2015-10-08 22:26:08
what tps are you actually using on the throttle body?
2015-10-08 23:43:21
TPS sensor issues, fed up - Can i run without it? Options??
Universal eBay throttle body with older pathfinder tps. Q45 tps is same but rotates the wrong way.

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2015-10-08 23:44:42
TPS sensor issues, fed up - Can i run without it? Options??
With the tps at .45 - .50 at closed it will only go like 3.5 or so wot. Seemed a bit low??

You can't set the tps above like .60 closed because it does all this weird shit to get that 4.0volts wot

Dave. What are these features? To get around fuel cut I had to raise it to the max. It was cutting out before at like 2,300rpm. It's fine now.

Wot is no problem it's just the low speed, light throttle driving.

The bad tps was making my a/f bounce from full rich to about 15:1. Causing constant misfire. With it unplugged a/f is steady and car drives great lol

What to do.......

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Last edited by Haulin200sx on 2015-10-09 at 00-01-29.
2015-10-08 23:58:59
That does seem a little low. If my theory in tricking the ECU is correct, you want to see 4.0V or more at like 40% throttle.
But even if you're not trying to trick the ECU, that does seem a little low.
2015-10-09 00:05:33
TPS sensor issues, fed up - Can i run without it? Options??
Ben I need it the other way around. Cruising normally the tps is only going from like .45 closed to .6-.7 volts open. The throttle is so big it only needs to open very little in normal driving where a stock size throttle would see .45 to 2-3 volts

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2015-10-09 04:13:50
I know, my post was a little confusing. Sorry. I'll try again.

If you're trying to get this OEM correct which might help then you're seeing too low of voltage at WOT. You already know this.

However, if you want to try to trick the ECU into providing the appropriate tip-in enrichment and such, you could try to make it see full voltage at something like 40% throttle or maybe even less. I have no idea if your TPS could be adjusted this way, or if you could even pull it off with some resistors or not. I wonder if your ECU has TPS calibration capability? That would make this 100x easier.
Last edited by BenFenner on 2015-10-09 at 04-16-19.
2015-10-09 04:19:50
You've added a lot more info to the original post since I read it. You were incorporating some Alpha-N aspects? Can't say I see that being helpful unless you are using ITBs with no MAF.
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