Jumpy throttle, need some advice

[qkslvr221]

When applying a small amount of throttle, my car sort of "lurches forward" for a split second. This only happens when going from not giving it any gas, to applying even a hair of the throttle.
I was thinking my throttle body was dirty, but man that thing is clean enough to eat out of!

This really makes driving jumpy, and trying to creep around at low speeds turns my car into a mexican jumping bean. :cuss: What gives?

 

[STAMPEDE3]

TPS may have a dead spot just off idle.
Put a volt meter on the middle wire, Key on motor off.

At 0 throttle it should be around .97-.98 volts. Now by hand or someone in the car. Very very slowly go down with the throttle. the voltage should rise up slowly.

If it hits a dead spot it will jump sporaticly, (sp) at the dead spot it may even fall of to nothing and then jump up to where it should be as soon as it passes it.

 

[98 svt]

Does the pedal seem to stick?

 

[Dano]

May even need to lightly lubricate all the pivot points in the linkage - from the pedal all the way forward.

 

[qkslvr221]

The pedal itself used to stick, but I did what Dano mentioned a while back and that was that. Where is the throttle position sensor located on these cars?

 

[98 svt]

The TPS is screwed to the side of the throttle body. Be careful not to strip the 2 screws.

 

[Mhissticobra]

If your pedal is sticking, try checking/cleaning your throttle body for build up as well as the others mentioned.

 

[98 svt]

If your pedal is sticking, try checking/cleaning your throttle body for build up as well as the others mentioned.

I was thinking my throttle body was dirty, but man that thing is clean enough to eat out of!

:rockon:

 

[98 svt]

Double post

 

[Mhissticobra]

How the hell did I miss that line? Thanks for pointing it out ......uhhh ummmm, what I meant to say was maybe you blew a turn signal gasket?

 

[qkslvr221]

Alright, gave it a test, and it pretty much stumps me.

No throttle it sat at 1.5v, WOT was ~5v. Number increased very smoothly but when I put it back to idle, I noticed that it stuck at 1.6 for a half second and then dropped to 1.5

Now, I don't have any high idle issues, it idles right around 750 and doesnt stick for long above that. How much would a .5v fluctuation cause?

Thanks again for the help :beer:

 

[qkslvr221]

Ttt.

 

[STAMPEDE3]

TPS at idle should be ~.97-.98
1.5 is way to high.
The ECM thinks you are already at part throttle and doesn't do anything until your foot goes far enough to make it start riseing past 1.5.

In other words if 1.5 is lets say 1/4 throttle the ecm doesn't do squat now until your foot goes past that point. So it is nothing nothing nothing and all of a sudden it jumps.

Change the TPS and make sure it is at .97-.98 at idle.

 

[qkslvr221]

Well the whole thing just doesn't make sense to me. If it's idling at 1.5v, wouldn't that cause me to have a high idle, or stall when taking off rather than jumping? The pedal doesn't have any "play" or anything.

 

[STAMPEDE3]

I agree it doesn't make a lot of sense, I would think it would have a high idle also.
Pedal doesn't need play to do what it is doing if I'm reading this correctly.

But 1.5 is way to high and can cause your problems.

Think of this again.
As your going down with the pedal it sees 1.5,1.5,1.5,1.5 and all of a sudden when you pass the spot where 1.5 actually is supposed to be, 1.6,1.7,1.8, and so on.

 

[qkslvr221]

So essentially, having the idle at a higher voltage is messing with my low-rpm powerband. Thanks again bro :beer: replacing this sucker tomorrow.

 

[98 svt]

You don't necessarily need to replace it.
Elongate the 2 screw holes for the TPS.
Then measure the voltage and turn the tps until you reach .97-.98V

 

[STAMPEDE3]

You don't necessarily need to replace it.
Elongate the 2 screw holes for the TPS.
Then measure the voltage and turn the tps until you reach .97-.98V

I was gonna tell him to try to adjust, but considering it is at 1.5 it probably has a dead spot.

TPS is nothing more than a rheostat. Odds are it is FUBAR'd at this point.

 

[BelvedereGTX]

You don't necessarily need to replace it.
Elongate the 2 screw holes for the TPS.
Then measure the voltage and turn the tps until you reach .97-.98V

that absolutely will not work if his setting is that high. Trust me, lol, ive tried that and wound up with nothing the screws will hold on to

 

[98 svt]

that absolutely will not work if his setting is that high. Trust me, lol, ive tried that and wound up with nothing the screws will hold on to

LOL, holy shlt.
I guess .5V IS quite a bit, huh?
Order it From Steve at Trously Ford. I bought mine a few months ago and got a great deal.
10% over cost = CHEAP!