Is there a spec for throttle plate setting at idle???

[Robert K]

I'm still hunting down a surging problem I have at steady state cruise conditions. Occasionally, I've also had the car surge after a hot restart. I've replaced plug wires, replaced a few vacuum hoses, and rechecked all intake system hose clamps. I took the throttle body off tonight and was looking at it and noticed that it barely had any opening at the throttle plate. Does anyone know if there is a spec on how far it is supposed to be open? I would assume that it should be open to a point that would allow the idle control valve to operate near the middle of its range. I wouldn't think that you'd want the majority of the idle air coming through the ICV. Any info would be appreicated.

Grace and peace,

Robert K
1991 535i

[Bill R.]

bottom of the throttle bore.

I'm still hunting down a surging problem I have at steady state cruise conditions. Occasionally, I've also had the car surge after a hot restart. I've replaced plug wires, replaced a few vacuum hoses, and rechecked all intake system hose clamps. I took the throttle body off tonight and was looking at it and noticed that it barely had any opening at the throttle plate. Does anyone know if there is a spec on how far it is supposed to be open? I would assume that it should be open to a point that would allow the idle control valve to operate near the middle of its range. I wouldn't think that you'd want the majority of the idle air coming through the ICV. Any info would be appreicated.

Grace and peace,

Robert K
1991 535i

[Robert K]

Bill,

With the throttle set to the .0015 opening and the ICV completely closed, do you think that the engine would receive enough air to idle? I just wondered what idle speed the .0015 opening should allow the engine to achieve.

I believe I checked the ICV out last time I was checking things over using the Bentley procedure of measuring resistance across the terminals. I may have to try it again when I get home tonight. This surging problem is getting very annoying!

Grace and peace,

Robert K
1991 535i

[winfred]

make sure that when the throttle is closed that the tps clicks and makes connection, otherwise the computer won't turn on the idle circuit. i set up throttle plates as per volvo's instructions, back off the stop screw till the plate just starts to stick when opened then tighten stop screw about 1/2 turn, then adjust tps so you get a good solid click everytime it's opened

[JonE]

I too have just recently experienced a couple of surges while on cruise control. It is as if the throttle was pushed briefly while on cruise, then settles back in. Winfred, am I understanding that this behavior might be related to throttle position sensor settings? If so, I guess I better find out how to do this. Is there info. in the Bentley manual on this condition/settings?
TIA

[winfred]

the tps only has two positions for the motor (the auto m30 has a full range rheostat for the tranny and the m50 has a full range tps) closed throttle and wide open (which closes around 75% of full throttle). it's hard to say whats pissing of the cruise, mabie a dirty spot on the servo if i had to venture a wild guess

I too have just recently experienced a couple of surges while on cruise control. It is as if the throttle was pushed briefly while on cruise, then settles back in. Winfred, am I understanding that this behavior might be related to throttle position sensor settings? If so, I guess I better find out how to do this. Is there info. in the Bentley manual on this condition/settings?
TIA

[Bill R.]

the dme

the tps only has two positions for the motor (the auto m30 has a full range rheostat for the tranny and the m50 has a full range tps) closed throttle and wide open (which closes around 75% of full throttle). it's hard to say whats pissing of the cruise, mabie a dirty spot on the servo if i had to venture a wild guess

[winfred]

the dme

[JonE]

So, is the servo serviceable/cleanable? Is this a cruise control related part?
Thanks again.