TPS, can the car live without it?

[bikerbill2021]

hey guys

so recently my throttle position sensor decided to give out on me on my 87 325_IS an hour from my apt, at my moms place. great timing for the holidays right?

i was getting a very odd stutter when it first started giving out, as well as a CEL, then i started getting a very violent bucking, to the point where the car couldnt be driven in normal traffic w/o odd looks from others, as well as giving me a headache. i traced the symptons to the TPS.

i disconnected it, and the car runs like a champ, just as good, if not better then before, just the idle is a tid bit higher, and the CEL will come on if its just idiling for more then like 10 mins, but will shut right off once the gas is hit.

now, im going to order a new one ASAP, but for the time being, can i get this thing back to my apt where my garage full of tools is, or am i gonna do more damage then good driving it around? i took it for a long spin the yesterday and it felt absolutely fine. the only thing i can think of it causing harm to is my MPG, which is not a huge deal at this moment

thanks guys/gals

P4C

[jlevie]

The biggest affect of not having the TPS connected is that the DME won't know when the engine is at idle (throttle plate closed). Other than causing idle problems that will have no affect of the engine. The DME won't know when the engine is at WOT either, but at this time of year in New York state, that is unlikely to be an issue.

When you replace the TPS, follow the procedure in the Bentley for adjustment of the throttle and TPS.

[bikerbill2021]

excellent, thats what i like to hear.

as per installation, yea ive heard the adjustment of the TPS has to be pretty spot on. my plan was to just take off the TB, mark where the old TPS was, and line the new one up in the same spot.

but ill take a look at the bentley, just for good measure

thanks man

[mikegar]

adjustment of the switch isnt too bad. you just turn it till you feel a click then turn it back till you feel no resistance.

[jlevie]

This is from memory, which can be faulty, but the procedure is:

1) With the engine at normal temperature and the ICV disconnected, adjust the throttle stop for an idle of 950rpm.

2) Adjust the TPS so that its idle switch closes (as evidenced by a test light or ohmmeter) when there is 020-040" of clearance between the throttle arm and stop.

Because of manufacturing tolerances and the fact that someone could have twiddled the throttle stop in the past, you need to correctly adjust both.

The usual cause of a failure of the TPS is oil leaking into it from the throttle body. If you drill a 1/8-3/16 hole in the bottom of the TPS in line with the throttle shaft the oil will have a place to leak out.

[bikerbill2021]

yea ive heard the common failure of this part is due to oil and crud getting into it, and the solution is to drill a hole into it, i may do that on the new switch to prevent it from happening

werd thanks for the info guys, setting this thing up with no tach should be interesting haha, but ill figure it out