TPS Question.......

[supraguy31]

How can you tell if you have a Dead Spot in yout TPS?

Ive set the TPS Using the 88 TSRM so Its correctly set. If I very slowly give it gas at Idle and it Hits a Certain RPM, The engine will start to rev up and down, up and down. I was driving it today and I hit that shot and the car started bucking back and forth.

Its like that rev up - cut fuel - rev up - cut fuel until I get out of that RPM spot.

I want to fix this so any help would be greatly appreciated.

Robert

 

[Nick M]

With a scope. It will show voltage over time, if you don't know what one is.

http://cgi.ebay.com/New-FLUKE-97-SC...yZ104247QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Your symptom is strange. If you have a dead spot, you will go lean, but not by much.

 

[dumbo]

How can you tell if you have a Dead Spot in yout TPS?

Ive set the TPS Using the 88 TSRM so Its correctly set. If I very slowly give it gas at Idle and it Hits a Certain RPM, The engine will start to rev up and down, up and down. I was driving it today and I hit that shot and the car started bucking back and forth.

Its like that rev up - cut fuel - rev up - cut fuel until I get out of that RPM spot.

I want to fix this so any help would be greatly appreciated.

Robert

TPS volatge has nothing to do with RPM, a dead spot would cause the car to basically die, tps would read 0volts, an open

 

[dumbo]

With a scope. It will show voltage over time, if you don't know what one is.

http://cgi.ebay.com/New-FLUKE-97-SC...yZ104247QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Your symptom is strange. If you have a dead spot, you will go lean, but not by much.

you dont need one of those, a regular volt meter will do it.

http://img.photobucket.com/albums/v293/heedah007/maftpropre89diagram.jpg

connect to VTA and ground and have a friend VERY slowly press the gas pedal, if at any points it gets lower volatge reading, thats a prob. approx .5v is idle, and( tsrm states WOT) my wot is 3.48v

but i bet it aint your tps, you got any codes?

 

[jetjock]

Actually it's what codes he doesn't have that could point to the problem...

 

[dumbo]

Actually it's what codes he doesn't have that could point to the problem...

interesting...please go on.:icon_surp

 

[jetjock]

He didn't say what rpm it cuts out at but it could be the IDL contact isn't opening or is intermittently shorting. That results in rpm cut, something that sounds similar to his symptom. He should:

1) Jumper T and E1.

2) Key on, engine off.

3) Slowly press gas pedal to the floor.

4) Check for a code 51 at every pedal position except idle.

VTA can be checked as you described. That said the engine will not die with an open in either of those circuits. In fact it'll run pretty well with the TPS unplugged, something else he may want to try.

 

[dumbo]

He didn't say what rpm it cuts out at but it could be the IDL contact isn't opening or is intermittently shorting. That results in rpm cut, something that sounds similar to his symptom. He should:

1) Jumper T and E1.

2) Key on, engine off.

3) Slowly press gas pedal to the floor.

4) Check for a code 51 at every pedal position except idle.

VTA can be checked as you described. That said the engine will not die with an open in either of those circuits. In fact it'll run pretty well with the TPS unplugged, something else he may want to try.

i dont understand how you check code 51 not at idle?? actually its not very clear at all, sorry. but i'm not wanting to jack his topic. i think you've gave him a good start.

 

[dumbo]

OHHHHH if code 51 goes away, at any throttle pos... thats bad

 

[supraguy31]

hmmmm.... Let me start checking.

 

[Nick M]

I thought he might not be plugged in.

 

[Nick M]

you dont need one of those, a regular volt meter will do it.

http://img.photobucket.com/albums/v293/heedah007/maftpropre89diagram.jpg

connect to VTA and ground and have a friend VERY slowly press the gas pedal, if at any points it gets lower volatge reading, thats a prob. approx .5v is idle, and( tsrm states WOT) my wot is 3.48v

Good luck.

 

[supraguy31]

He didn't say what rpm it cuts out at but it could be the IDL contact isn't opening or is intermittently shorting. That results in rpm cut, something that sounds similar to his symptom. He should:

1) Jumper T and E1.

2) Key on, engine off.

3) Slowly press gas pedal to the floor.

4) Check for a code 51 at every pedal position except idle.

VTA can be checked as you described. That said the engine will not die with an open in either of those circuits. In fact it'll run pretty well with the TPS unplugged, something else he may want to try.

Ok, did said check and without pressing the Pedal, I dont have a Code 51, As soon as I give the pedal a little press, Code 51 comes up and I have that code all the way down to WOT. only thing that I noticed is when my Pedal is 100% down, Im reading 3.08v on my MAFT Pros TPS reading.

 

[dumbo]

Ok, did said check and without pressing the Pedal, I dont have a Code 51, As soon as I give the pedal a little press, Code 51 comes up and I have that code all the way down to WOT. only thing that I noticed is when my Pedal is 100% down, Im reading 3.08v on my MAFT Pros TPS reading.

yah that is below spec.. i would get a friend to check your reading, and manually open the tb under the hood. and if that isn't it, maybe jetjock will share some knowledge.


since you got it hooked up to your maft..you can just use that as your voltmeter...thats how i've checked mine.