Alpine951

I am trying to track down a problem on my car. I just got it all put together after a long winter of suspension upgrades, k27/6, 65# injectors, new vacum lines, and new chips. The car ran fine before all of this. Now it bucks and stumbles on boost. I am wondering if the TPS all of a sudden crapped out on me. I was thinking of going out for ride at lunch and disconnect the TPS to see what happens as i am trying to diagnose if its the propblem. I was going to bring in a volt meter and test it per clarks garage at the DME connector, but forgot it.

Jeremy Himsel

Alpine, if you disconnect the TPS it'll run, but not very good and will idle pretty high. SInce your condition is only on boost I would be worried about your A/F ratio's before you continue. Bucking and stumbling under boost is usually and indication of bad things happening. What do your plugs look like? Certain "tuners" have a history of burning chips that pop motors so beware.

Dilberto

Disconnect TPS=No Fire.

Alpine951

I think I will replace the plugs since they are a few years old anyway, and they are cheap.

tammons

You can read the blink code to determine if you have a bad TPS

mroberts

I had an issue where as soon as I hit 7psi, the A/F ratio went nuts and the car bucked and shuddered. The problem turned out to be the BOV hose - it was just loose enough that when it was hot and under boost, air could blow by.

You may want to check your intake connections - IC pipes, BOV, etc.

Alpine951

Do I have to build a tester like in Lindsey's website or is there another tester that will work?

Alpine951

By the way I pressure tested the intake over the weekend. i ripped out the ISV and plugged the ports because it was leaking. The only other leak at the moment is coming out the side of the throttle body where the accelerator cable is. Reseal kit will be needed.

mroberts

You mean the one made of two parts from Radio Shack ?

I have the diagnostic LED permanently wired into my gauge plate - it's becoming quite handy.

Oddjob

If the KLR determines a fault with the TPS, it will likely run in the safe mode - low boost, retarded timing. But that does not mean there isnt a problem with the TPS, but I dont think that bucking and stumbling is a bad TPS.

You can drive with it disconnected, but as mentioned it will idle very high, around 2-3000 rpm, and it will have odd let off characteristics. Since its disconnected, the KLR will for sure identify a problem with the TPS and will run in the safe mode and give you the blink code fault.

AlexE

It will run with the TPS disconnected.

It will run on part-throttle maps. These are 3D maps and will be fine for a while. You can bring the idle down to ~1500 if you like to drive it.

A bad tps can definitely give you on boost troubles. Have you done the troubleshooting for it.

Bucking on boost ......I would check your hard pipes to make sure they are secure and not coming loose on boost.

dime1622

i run with no tps, and can drive all day. kinda low-power, but whatever. hehe, otherwise i have severe idle problems. im working on fixing it.

Alpine951

Clarks garage says to connect an ohm meter to the #2 terminal on the DME harness and ground. What does and ground mean?