need advice and help again please
Moderator: martauto
-
Grrrmachine
- E30 Zone Wiki / Team Member
- Posts: 8043
- Joined: Sat Feb 09, 2008 11:00 pm
- Location: Warsaw, Poland
Gummed up or knackered Throttle Position Switch, like every other M20 lumpy idle
'89 325i Touring | Touring Resto Thread | In-Dash Screen install
-
Cloggy Saint
- Old Skooler
- Posts: 8024
- Joined: Sun Jan 09, 2005 11:00 pm
- Location: zummerzet
It's on the underside of the throttle body, you can't miss it. It pays to drill a small hole, maybe 1 or 2 mm right in the very centre of the switch. It won't do it any harm but it allows the crap to seep out.
E30 zone - promoting adult illiteracy since 2004
-
Brianmoooore
- E30 Zone Team Member
- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
Air leaks into the inlet side of things anywhere after the air meter can also cause these problems, aided and abetted by injectors that are 50,000 miles past needing a rebuild.
Remove the air filter assembly, then the large convoluted air hose (checking it for cracks and splits), and you will see the TPS sitting at the lower end of the throttle butterfly shaft.
Pull off the three pin plug, and check for continuity between two of the pins. The meter reading should go to infinity immediately the throttle is moved off of its stop, and become short circuit again as soon as the throttle is released.
The switch fails because oil in the throttle body runs down the shaft and into the switch, from which there is no escape. The cure is to remove the throttle body, complete with switch, and to drill a 1mm hole right in the middle of the BMW roundel on the underside of the switch.
A bit of switch cleaner or isopropyl alcohol into the hole, allow to drain, and the switch should come back to life.
Remove the air filter assembly, then the large convoluted air hose (checking it for cracks and splits), and you will see the TPS sitting at the lower end of the throttle butterfly shaft.
Pull off the three pin plug, and check for continuity between two of the pins. The meter reading should go to infinity immediately the throttle is moved off of its stop, and become short circuit again as soon as the throttle is released.
The switch fails because oil in the throttle body runs down the shaft and into the switch, from which there is no escape. The cure is to remove the throttle body, complete with switch, and to drill a 1mm hole right in the middle of the BMW roundel on the underside of the switch.
A bit of switch cleaner or isopropyl alcohol into the hole, allow to drain, and the switch should come back to life.
its bolted onto the bottom of the throttle body, 2 screws hold it in place, remove it and give it a good clean with some contact cleaner in the hole.. when u put it back on you have to make sure its set right.
once its bolted on put your ear to the throttle body and very gently open the linkage, you will hear a 'click' the second you move the linkage, if the linkage move a few mm before the click sounds, you need to loosen it off and set it closer. also check your air hoses for cracks/splits. air leaks will make it run lumpy too
once its bolted on put your ear to the throttle body and very gently open the linkage, you will hear a 'click' the second you move the linkage, if the linkage move a few mm before the click sounds, you need to loosen it off and set it closer. also check your air hoses for cracks/splits. air leaks will make it run lumpy too
