E30 Zone

Hi people, ive just swapped the throttle body on my 320i (e30 1989) for a newer and bigger 325i version. having finished the conversion the car now idles at 3000rpm!!! very cleanly mind, but obviously far too high, anybody had similar problems?
i need the car for work tmoro morning, and dont fancy swapping it all back tonight!!

Sounds like you've got a big air leak, did you fit a new 325i gasket ?

Cheers,

Iain T

Thanks for the reply mate, i didnt fit a new gasket, but my ones ok, ive had a look/listen for air, but it seems fine in that respect. it revs really crisply, and idles smoothly, its just like its set far too high

there is a little sort of screw that can be ajusted with an allen key mebbies it has been wound in too far and need's wound out a bit as it could be keeping the flap open? or the accel cable is stuck and not in posision properly ??

where in the north east are you from mate?

Im in sunderland mate, the butterfly in the throttle body operates properly, closes fully etc, i checked it worked before fitting it, and the cable allows the throttle to close fully too, goes nice and loose when sat in the closed position... the throttle body was off the zone, and i noticed its been cleaned very thourally, is there an adjustment on the 325 throttle body that can make that much difference, ( but not on the actual butterfly as ive checked that) that the lad i bought it off might have moved about to clean the unit?
thanks for your reply mate

I have JUST changed the throttle body and elbow by the way, not the AFM or anything else at all to do with the throttle body, so should i have put a 325 afm on it too? (i also serviced it today with new oil, filter, dizzy cap and rotor arm....cant really see any of that making a difference)

just took it for a drive, and as the engines warmed up it seems to have improved, but still idling at 1800-2000rpm, and is very slow to drop once youve blipped the throttle...its wierd, ive tried the obvious thing of bashing everything in the engine bay with a hammer, but it still didnt fix it! that done im really stumped...

Did you set the TPS?

Mine worked loose once and made the car idle high....

Matt

nope, how do i do that mate?

have you got a multimeter? if you have call me on 07799817972 and i'll tell ya how to do it,

Tel

yeah ive got one, whens a good time to phone mate?

stabb in the dark really mate but are there any leaks around the pipes for the idle air controle valve?

A good way to check is to spray brake cleaner round a small area at a time, when the vapour gets sucked in the revs will rise

Some say to use carb cleaner which works the same but evaporates more slowly.

With the engine off, operate the throttle lever/butterfly by hand - as it just starts to move you should hear a quiet click. That is the TPS switching.

If you get this then do the multimeter checks with telski

If you dont then you need to take the TB off and set it.

The stop screw for the butterfly should be adjusted to stop it closing completely (fraction of a mm) It should have thread lock on it to stop people playing with it, but if someones stripped and cleaned the carb it's probably set wrong.
Undo the screw until the lever is no longer touching it and then reset it so the butterfly no longer touches the wall when fully closed. Something like 0.5 of a mm but don't quote me on that.
Once thats done then you set the throttle position switch.

righty ho, the butterfly should be set to a 0.75mm gap, (checked with feeler gauges) which mine is, like the idea of spraying carb cleaner to test for leaks, will try that tmoro after church! the throttle position sensor clicks in perfic just as you open th throttle the tiniest bit, so i figure that is ok?? like i say i checked all the pipe work on the car when i did the conversion, and it all seemed ok, plus the fact the car ran sweet up until i did the conversion... its very strange, gonna have a real good bash at it tmoro hopefuly, so any more suggestions welcome!! Thanks for the help so far guys, much appreciated

i noticed something else today that might cast some light on the issue... Those of you that have the fuel economy dial will probably have noticed that while the car is moving if you let your foot comlpetely off the throttle the gauge flicks right up to 50+mpg (obviously enough) but there is a point, and i assume its when the throttle position sensor tells the ecu that its in idle position, where it noticably jumps up to that reading (foot completely off the throttle) mine has stopped doing that since friday when i did the conversion....hope this makes sense!! and triggers some ideas!! does this mean my tps is broken, or not working, or does it have nothing to do with it!?

Mine did that, when of the gas, rollong down a hill in fifth gear, the econo gauge never went above 50Mpg, It turned out to be a knackerd TPS switch, as the ecu never knew i was of the gas........

I changed the TPS, and the econo gauge went way past the 50Mpg....

Need to check the TPS with a meter I think. Take the air hose off and it's easy to get to.

did your tps still click on and off tho? mine is doing. ive swapped the tb back to the 320i one until i get a new gasket on tuesday. Telski can i still phone you to run through that tps setup? if mines knackered can i swap it for the one off my 320 unit as i know that to be ok

Just because it clicks doesn't mean the TPS is good, although if it doesn't click, then it is dud or set up wrong.
320 and 325 TPS are the same AFAIK.

Is this a likely cause of the problems im having then Brian do you think? are they straight forward to swap over, and do i need to look out for any bits pinging out when i strip them down!? (oh yeah, what does AFAIK mean!?)
Kiesh

AFAIK = As far as I know.
To be honest, I don't think a dud TPS would result in a 3000 RPM idle, but you need to get things sorted one at a time.
It's never going to idle properly if the TPS is dud, as the ICV wont be doing it's stuff.

ok, i'll change it today and see if it does anything! i took the ICV off and cleaned it out, it wasnt too dirty, and the insides moved about freely enough, so i reckon it has to be something specifically wrong with the throttle body itself, (having put the old one back on and found the car to run perfic again)

does anyone know if you can test the TPS while its off the car to see if its workin properly?? i have a multimeter, and have taken the tps of the throttle body... Telski, is this the test you were talking about?

Yes, can be tested off the car.
Pins 1 and 2 short circuit when throttle closed, open circuit when just opened.
Pins 1 and 3 open when throttle closed, short circuit when throttle about 2/3 open.

cheers Brian, much appreciated

FIXED!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Finally sorted it, turns out to be the TPS which wasnt working (thanks TouringMatt, Kam-325, etc), i put the multimeter on it and wasnt getting any resistance on the closed throttle position (thanks for the tip Brian), ive swapped the tps for my old one (which is also virtually knackered, makes the car jolt when you let off the throttle, but it'll do till i get a replacement!!) and fitted the new throttle body again, car's noticably quicker (i ground out the inlet manifold too) and has much crisper low end acceleration, am very pleased!

Thanks again Everyone that made suggestions, hugely appreciated!
Kieran
p.s. anyone got a good Throttle Position Sensor?!