Howdy all,
I'm curious if the Throttle Position Sensor is adjustable for location with the throttle body still attached. I'm getting a code 63 (TP circut below minimum voltage). According to the Helms manual, it's voltage is adjustable by moving the sensor around until .9v-1.1v is registered.
Those phillips screws don't look accessable at all to me thanks to the verticle alignment of the throttle body bores. is there a special tool available?
Any help will be appriciated!
-John R.

 

Not sure what model you've got.

The TPS on my 88 E150 was NOT adjustable despite what the manuals said: I got all confused with it & so I pulled the throttle body off to check. You can do it with a 1/4" ratchet & a screwdriver bit in a small socket ;-)
An sdjustable TPS has elongated holes so you can move it back & forward, mine just had 2 round ones.

If you want to check it, get a meter and check it: it has 3 wires- I ground, I reference voltage & it's output. I put my meter between ground & the output wire on ohms, then slowly depress the meter & watch it sweep. It should be smooth- normally when they go bad you get a flat spot both on the meter & while driving.

 

Thanks a bundle for the info! It looks like it'll shape up to be a nice day for checking it out. I'm not looking forward to pulling the throttle body assembly though. It'd have been nice if they put it on the side like my '90 F150 w/I6. Oh well, it's still doable.
-John R.

 

For me, it was easier to pull the body: there are only 4 bolts and you can just spin it around to make it easier to get access to the TPS: the gasket is only about $2.

If the TPS has not been off before, you might find that poking around underneath with your socket & screwdriver bit just won't cut it.

I'd also look at that reference voltage- if it's low there then obviously you're going to get a low output. Unfortuantly I can't remember off the top of my head what it is, think it's a 5v input.

 

I can spend some time in the '87 emission/diagnosis manual to see what the referance voltage should be. It may not say though. As it stands now, it's raining here. I guess I'm paranoid, but this ole boy ain't foolin' with electrical crap in the rain! Not getting correct voltage is a reasonable possibility seeing as how I'm getting a code 98 as well as the 63.
-John R.

 

WOT, voltage should be 5v +/- .2v, idle voltage should be .7~1.0 volt.