correct tps reading now will not start

[ghettoslide]

I bought a used tps from a salvage yard, pulled out my multi meter and set per instructions here somewhere. I put it on the car new gaskets now it will not start just cranks. I replaced because i have been fighting this car since i bought it a year ago. I could get it to start after replacing parts to get the cel light off. It idle surged mad. Later i got it ti run, still surging a bit would not rev past 2500. Fixed that, noticed it makes boost while sitting still not in gear if i rev it high. Is that right? should it make boost. I do not have the boost guge installed yet so i do not know how much. will install the gauges when the pods come in. I know it builds boost because the blow off valve is vented, bought it this way. Found the stock one in the trunk put it on still have same problem so i ruled it out. when car was running i spayed starting fluid everywhere under the hood looking for vacuum leaks found nothing. Used soapy water to check for boost leaks found nothing. Adjust biss out and in with new tps nothing. when the car was running i drove it once to find that with my foot barly on the throttle like just resting the car would do 80 mph, another reason for replacing the tps. i do not have a logger i can only scan codes, can not afford a dsm link right now either so i relying soley on mechanical skill and voltage values. I think i am failing, someone please help.

 

[LiquidX]

After struggling to read that, did you set it properly on the TB? You can't just put it on any which way, it needs to be setup.

TPS Adjustment

 

[ghettoslide]

yeah, that is exactly how i did it to a " T ". It was the same sort of write up on how to do it. My values are right on, the only diffrence is my meter is digital. I am new to DSMs, and this is not a good way to start.

 

[jeffo]

Adjusting Idle switch 91-94 TB - DSM Forums: Mitsubishi Eclipse, Plymouth Laser, and Eagle Talon Forum: DSMtalk.com
But, I actually prefer to setup the TPS by voltage, instead of resistance. You want to see ~0.5 volts out of the TPS with the throttle closed, and 0.95 to 1.0 volt with the gas pedal the whole way to the floor. But, with a 2G its is also very important that the idle position switch part of the TPS be working. You want to see continuity between pins 3 and 4 when the throttle is closed. I find way too many 2G cars that the IPS isn't adjusted right.

 

[steve]

After struggling to read that, did you set it properly on the TB? You can't just put it on any which way, it needs to be setup.

TPS Adjustment

The VFAQ is just plain wrong and totally wrong for a 2G. If you want to know why it's wrong you can search one of the many time here that I've explained it.

Adjusting Idle switch 91-94 TB - DSM Forums: Mitsubishi Eclipse, Plymouth Laser, and Eagle Talon Forum: DSMtalk.com
But, I actually prefer to setup the TPS by voltage, instead of resistance. You want to see ~0.5 volts out of the TPS with the throttle closed, and 0.95 to 1.0 volt with the gas pedal the whole way to the floor. But, with a 2G its is also very important that the idle position switch part of the TPS be working. You want to see continuity between pins 3 and 4 when the throttle is closed. I find way too many 2G cars that the IPS isn't adjusted right.

The fourth post in that thread quotes a post or mine from this site in 2004. http://www.dsmtuners.com/forums/tuning-engine-management/141266-throttle-pos-sensor.html#post1153585

On a 1G if and not running DSMLink you need to set the IPS voltage to about 0.5v (0.48 to 0.52 is the spec). You can do it be resistance if, you measure the total resistance of that specific TPS and the actual +5v sensor voltage, then use those values to computer the correct values for a voltage divider that will give you 0.5v out. I also find it simpler to just measure the voltage or use my logger and twist the TPS on the car to get the right value.

On a 2G you must set the IPS switching point. The output voltage has such a wide range that it pretty much doesn't matter because a good TPS will meet it.

 

[ghettoslide]

i adjusted the biss both ways, but if you are refering to the screw behind the throttle that holds the plate open you could be right i forgot about it. It was not on the throttle i bought so i swapped it from the other probably not right.I will check it and get back to you.

 

[steve]

No one is talking about the BISS or the fixed idle stop screw.

On a 2G throttlebody there isn't a external IPS it's inside the TPS so turning the TPS is how you set it.

 

[ghettoslide]

OK, i will go pull it off the car again and reset it.. I tightned it down once i got it right the last time so moving it on the car is not going to happen. I will try and take pics of my readings when i get it dialed in. Thank you guys for the help, this car is beating my wits all the way around.

 

[rush2252]

Am I overthinking this or misreading? To my knowledge my 2g started and ran when my TPS went bad. It wasnt the smoothest idle and the cleanest acceleration but it still went forward

 

[steve]

Am I overthinking this or misreading? To my knowledge my 2g started and ran when my TPS went bad.

No, I think your spot on that messing with the TPS isn't going to make the car run.

I'm just responding to the bad data posted since the OP has already decided to mess with the TPS.

 

[ghettoslide]

OK so maybe i should leave the tps on now if that is not making the car not start. With the old one on i could get the car start and idle by moving the tps around. Once started i could drive the car, but it would go like 80mph in 5th gear without me pressing the throttle at all. when i pressed the throttle it would slow down then make it's way back up to spped. sometimes when i tried to drive it it would just buck like mad when i pressed the throttle. That is what lead me to the tps. Any help would be appreciated greatly. I have a friend the next town over, he was the original owner of the car before he sold it to some guy, who happened to be the guy i bought it from. Small world, i am going to go talk to him after christmas. I may have to use my avalanche to tow this bad boy to a shop.