Idle Stuck at 4,000rpm

[olskool]

It happened again. After driving for several miles, the engine revs to about 4,000rpm and is stuck there, then check engine light comes on, and the engine cuts off.

I did a stomp test and it shows a fault code of 1262 Idle Speed Actuator. What do I need to do to resolve this problem? Is this the cause to the stuck engine rev?

I just replaced the alternator. Any chance the new alternator is causing a short circuit to the system?

Where is the Idle Speed Actuator located? Please help would be greatly appreciated

[TDE30]

Had this issue with my father's S38, it ended up being the throttle position switch. If these cars have that, I'd look there as well. IIRC, it's right in the vicinity of the throttle body.

[DCColegrove]

DME 1.3?

ISCV (or connections)

[JAM]

make sure the throttle cable doesnt have any broken clips and it isnt getting hung up on anything... as stupid as that may sound...

[olskool]

DME 1.3?

ISCV (or connections)

I checked the icv connections and also cleaned the icv with TB cleaner.

Not sure I understand your first question though "DME 1.3?"

[BMWLA]

I checked the icv connections and also cleaned the icv with TB cleaner.

Not sure I understand your first question though "DME 1.3?"

the idle valve is shot what DC is talking about is what Motronic system you are talking about.

when the ICV goes bad on the 55 pin DME (v1.3) the idle either shoots to 4k or wont idle at all.

[olskool]

the idle valve is shot what DC is talking about is what Motronic system you are talking about.

when the ICV goes bad on the 55 pin DME (v1.3) the idle either shoots to 4k or wont idle at all.

How do I find out which version Motronic I have?

Also, when the ICV goes bad, does the idle shoot up to 4k rpm and stays there before the engine cuts off by itself, much like what I am experiencing?

[DCColegrove]

How do I find out which version Motronic I have?

Also, when the ICV goes bad, does the idle shoot up to 4k rpm and stays there before the engine cuts off by itself, much like what I am experiencing?

9/87 up is DME 1.3 (55pin Bosch Motronic). The ISCV (Idle Stabalizer Control Valve) will have 3 wires rather than 2.

and that's what they do when they go kaput...

4k or nothing.

[reelizmpro]

Idle Control Valve like the others have stated. Assuming you have a 325i, make sure you get the right valve. Early cars had an "L" shaped valve and later 89-on cars had a "T" valve. They also use different boots. What is the year and model of your car?

[combustion325ix]

Im gonna go out on a limb here and disagree with everyone else. My theory is that your car wants to go fast and when you freak out and start stomping the throttle instead of dropping the clutch your car is like screw you i will throw a cel and shut down since you wont let me run wild. Or your car could be a decepticon

[BMWLA]

Im gonna go out on a limb here and disagree with everyone else. My theory is that your car wants to go fast and when you freak out and start stomping the throttle instead of dropping the clutch your car is like screw you i will throw a cel and shut down since you wont let me run wild. Or your car could be a decepticon

:drink:good call i think you may be right here

[olskool]

Idle Control Valve like the others have stated. Assuming you have a 325i, make sure you get the right valve. Early cars had an "L" shaped valve and later 89-on cars had a "T" valve. They also use different boots. What is the year and model of your car?

It's a 1990 325is and it looks like I have the "T" valve. Damn, Bavauto has it priced at $168. I sure hope a new ICV solves the problem. Thanks everyone for your input. I'll let you know how it turns out.

[kid325e]

:drink:good call i think you may be right here

hahaha.

[Reign]

It's a 1990 325is and it looks like I have the "T" valve. Damn, Bavauto has it priced at $168. I sure hope a new ICV solves the problem. Thanks everyone for your input. I'll let you know how it turns out.

Well, instead of gambling, why don't you take it to a good mechanic and making sure that's the problem. It's a big issue for someone to gamble on and hope they are right.

[BMWLA]

Well, instead of gambling, why don't you take it to a good mechanic and making sure that's the problem. It's a big issue for someone to gamble on and hope they are right.

no srsly it is the ICV for sure