ohvrolla wrote:Verocity my uphill steady throttle buck ended up being a bad TPS sensor.

Ryan, if you figure it out LET ME KNOW. My car acts just like that, in second gear only as well. Isn't terrible, but you can just sorta tell it isn't accelerating smoothly under a constant throttle. If I roll into the throttle it's smooth. WOT it's smooth. Just anything over half throttle or a little more and you can tell. Only does it with a steady pedal as I can increase the throttle and it goes away. I have noticed that if I've had my battery unhooked while working on something it seems to go away for a few days.

EXACTLY. Though mine started doing it at WOT now too. It doesn't do it when it's cold, and it is the worst under a load going up a hill. Just like you, when I reset the ecm, it doesn't do it for a couple days until it "learns" the car, and screws everything up. Maybe I'll try the TPS and see how that works. If I have time I may try something with the fuel pressure regulator too. Thanks for the ideas guys.


"In Oldskool we trust"

TPS, never thought of that! Heres the thing also, (still means it could be bad though) awhile back I tried doing the 2.3 HO TB conversion on my car...Long story short I couldn't find the right sensors for the TB and I needed my car to drive. The TPS sensor that was on the car had got messed up (the plastic got cracked) and I had to go buy a new TPS from Advance.

Realizing this now makes me think I have a aftermarket POS TPS sensor that may be screwed up, I don't think that by looking at this sensor I can tell if it is 'bad'. I guess the only way to tell is like you where saying earlier, get one from a yard.

My old engine did this too, and I got a code once that came back to the TPS being screwed up. But since I put a newer one in (~50K on it), including the new throttle body and sensors, it still does it.

Verocity wrote:Realizing this now makes me think I have a aftermarket POS TPS sensor that may be screwed up, I don't think that by looking at this sensor I can tell if it is 'bad'. I guess the only way to tell is like you where saying earlier, get one from a yard.

Maybe find someone with a scanner and see if it's adjusted right. For instance, does 100% on the pedal read 98% on the scanner. I can imagine that would create problems if it wasn't dialed in correctly. I hooked mine up, seems to be working properly and accurate.


"In Oldskool we trust"

TPS went out on my original TB and replaced it, but 2nd gear acceleration was still not 100%. Changed to a 2.3L TB later on and 2nd gear is still the same. Like Ryan has also noticed it doesn't happen for a few days after a ECM reset. It isn't bad like the car is bucking, and truth be known I'm usually not on the gas enough or turn the motor over 3K so the car isn't under the right conditions for it to happen.

Ryan Pitt wrote:My old engine did this too, and I got a code once that came back to the TPS being screwed up. But since I put a newer one in (~50K on it), including the new throttle body and sensors, it still does it.

Verocity wrote:Realizing this now makes me think I have a aftermarket POS TPS sensor that may be screwed up, I don't think that by looking at this sensor I can tell if it is 'bad'. I guess the only way to tell is like you where saying earlier, get one from a yard.

Maybe find someone with a scanner and see if it's adjusted right. For instance, does 100% on the pedal read 98% on the scanner. I can imagine that would create problems if it wasn't dialed in correctly. I hooked mine up, seems to be working properly and accurate.

Can the scanners at autozone or advance check for this?

Verocity wrote:[Can the scanners at autozone or advance check for this?

They can if you can find someone with enough intelligence there to know how to do more than read a code.

Chris wrote:They can if you can find someone with enough intelligence there to know how to do more than read a code.

And good luck with that...


"In Oldskool we trust"

haha!

So I'm starting to think it isn't the TPS, I just noticed something with mine and I got a video too to show after I get it off of my phone...

I had been running 100% gas in my car from Shell, no ethanol at all. And recently I had to get some gas, no choice of 100% gas where I was at. So I got some 10% ethanol junk that almost all places have. My car does it alot worse now and I floored it getting on the on ramp to get up to 70 the speed limit, kept it down and got it up to about 85. It never jerks under WOT.

Also, after flooring it, it seemed it had kind of fixed it, but then it started to do it, but not as bad as before I floored it..This little issue is just really starting to piss me off.

So far what I know:

1. Steady foot at about 70 mph (2500 rpms) it will jerk here and there and rpms will jump to 3000 and come back down occasionally. (video of it soon)

2. Doesn't do it as bad with 100% gas.

3. Steady foot, then off of throttle slowly it bucks a little bit and rpms (and throttle?) seem to hold for a second and then come down.

4. It pisses me off.

I still haven't had time to check anything ...so busy, work,school, tomorrow im going to check somethings, promise. And I think im going to run some injector cleaner.

I hate going to the pump and seeing the ethanol added sticker. Also, I know for a fact that most say 10% when that simply isn't the case. The guys at sheetz and hess around here tell me that when they look at the gas receipts, the ethanol content is actually more like 12% and sometimes more. Ridiculous. I also hear that the winter blend of fuel is different from the summer blend, which makes a difference not only in performance but in mileage as well. I have not researched this but if anyone knows anything more about that let us know. Maybe that's just a myth. There could be something to high ethanol contents messing up our tunes. Maybe it's time I post this in the tuning forum and see what those guys have to say. I think we've pretty much established that this is a sensor/tune issue. I can't imagine we ALL have clogged injectors and/or fuel filters. I've been busy at work too; just had our shift change. Plus I jacked my shoulder up busting some woman's door in because she was threatening suicide, so I don't feel like doing much right now...


"In Oldskool we trust"

Ryan Pitt wrote:I hate going to the pump and seeing the ethanol added sticker. Also, I know for a fact that most say 10% when that simply isn't the case. The guys at sheetz and hess around here tell me that when they look at the gas receipts, the ethanol content is actually more like 12% and sometimes more. Ridiculous. I also hear that the winter blend of fuel is different from the summer blend, which makes a difference not only in performance but in mileage as well. I have not researched this but if anyone knows anything more about that let us know. Maybe that's just a myth. There could be something to high ethanol contents messing up our tunes. Maybe it's time I post this in the tuning forum and see what those guys have to say. I think we've pretty much established that this is a sensor/tune issue. I can't imagine we ALL have clogged injectors and/or fuel filters. I've been busy at work too; just had our shift change. Plus I jacked my shoulder up busting some woman's door in because she was threatening suicide, so I don't feel like doing much right now...

Well, most people are running E10+ just fine, so I think you may be chasing a ghost in that direction. I believe my last ethanol newsletter said regulations were recently passed to allow up to E15 at pumps now. If that was going to cause problems, auto manufacturers would have stopped the legislation easily.

I think you should try resetting your ECU and letting it idle for a few minutes when you change fuel blends so radically.




fortune cookie say: better a delay than a disaster