TPS testing without the breakout harness

[kjmdes]

I'm new here and have an 06 blast. I've done the airbox mod, PCV hose mod, and have a new Boot. Timing looks good, but coming off idle and to what I'm guessing is about 2500rpm, it runs like crap. Vibrates way too much. Carb looks good, jets (stock)look good. It's run like this since before the mods, and it's always crapped out way soon at the top end.

My question, how do I test the TPS without the breakout harness? I'd like to put a meter on it as per the standard method, but without the special harness.

Cheers

 

[crxtasy169]

Put your pocket tester on ohms setting, disconnect the tps from the harness put the tester on the 2 wire and twist the throttle the value should change progressively as you twist the throttle then when you left off it should return to the value you started at.

 

[crxtasy169]

If there is a major change in the 2500 area that may be the problem, if all seems smooth it probably is not the problem.

 

[kjmdes]

Thanks for that. Is there a baseline resistance to look at. Throttle closed=x value. They state reference voltages in the manual. So just wondering what I should be looking at with the butterfly completely closed with the idle screw backed off.

And while we are on the subject of "not quite right" stuff. It has the noisiest valve train I've heard for a long time, I'd guess I have a dead lifter, which could account for the top end dropping out.

Thanks again

 

[crxtasy169]

The best test for a bad lifter is a mechanics stethascope, you can get one at places like harbor freight or harborfreight.com place it right around the lifters on the head and you'll know by the sound if you have a bad one it will be extremely loud and the scopes are less than 10 bucks they are awesome tools to keep around.

As far as the specific resistance value I'm unsure you need a manual or to contact your local Harley dealer to find out. In the mean time I'll see if I can find out for you. Best of luck!!!

 

[crxtasy169]

Oh yeah I wouldn't mess with the Idle screw if it idles ok now! Don't try to fix what isn't broken old proverb!

 

[Ctessmer]

The tps voltage with the idle screw backed all the way out should be 0.5v +/- 0.05v, according to the service manual. Unfortunately I can't get mine to go below 0.9v.

 

[Ctessmer]

I have completely dipped and cleaned the carb, set the float, adjusted the tps, made sure it was static timed correctly, etc, yet it is hard to start and will not idle. I haven't found an air leak either. While I'm revving the bike, it has gas vapor spraying out of the rear of the carb. The voltage on the tps moves from idle to full throttle smoothly, but as I mentioned, I can't get it to go below 0.9v. Any ideas? This is my girlfriend's bike and I want it to run properly, but at this point, I want to turn it into a boat anchor! HELP!!!

 

[orange guzzi]

You probably have a tight intake valve. You can check the compression with a compression tester with the carb off.

You can also use put it on top dead center and use your compression tester hoses to put compressed air into the cylinder. If air blows out the exhaust the exhaust valve is tight, if air blow out the intake, the intake valve is tight, if air blows out the crankcase vent, the rings are shot. Be sure to put a wrench on the crank or clutch to keep the motor from turning over when pumping air into the sprarkplug hole. The compressed air will try to blow the piston back down.