1994 530iA ASC light always on, late shifting

[94530inh]

So, i've been doing some work on my car. Replacing the intake manifold gasket, water pump etc etc. I've done and re-done this job a few times just to make sure I didnt mess up the install. Anyways, now my ASC light is on and the car shifts at really high RPM and doesnt shift nearly as early as it used to.

I'm wondering, is there an adjustment I can make? Special troubleshooting I can do? I'm about ready to get a replacement trans. but I know that there is hope for the current transmission in the car.

At WOT the car shifts flawlessly.

Thanks

[Mutinus]

Did you check the cable between the prethrottle and the servo motor? Might have bound it up and have it stuck causing your ASC light.

[m60b30530i]

Did you check the cable between the prethrottle and the servo motor? Might have bound it up and have it stuck causing your ASC light.

what does this do my pre throttle cable is pretty loose could this cause the motor to have a high idle

[Mutinus]

what does this do my pre throttle cable is pretty loose could this cause the motor to have a high idle

Probably wouldn't have much to do with idle. It should loose/floppy if you tug on it a little. Not pulled tight. The prethrottle is supposed to be in the WOT position most of the time till the ASC kicks in. ASC first uses the antilock brakes to regain traction and if it can't that way it uses the prethrottle to cut the power till you regain traction. When you first start the car the system does a full range check of that throttle. I know from first hand experience that if it hangs up (fails the check) then it disables the ASC and turns on your light. So if you don't have an accompanying ABS light I would check out the prethrottle first. If you have both lights I'd check out the ABS wheels sensors.

[m60b30530i]

yeah mine does tighten up at start up

if i were to remove this could i see some power gains , its seems to disrupt some airflow :)

[Mutinus]

yeah mine does tighten up at start up

if i were to remove this could i see some power gains , its seems to disrupt some airflow :)

If it's working properly I doubt it. Pull the short "accordian" hose off from between the airbox and the Throttle body. The prethrottle is right there in front. If it is returning to full WOT then it's not robbing you of any power. If it's sticking in the middle somewhere then lubricate till it returns to WOT. Assy is the reverse of dissassy. LOL.

[m60b30530i]

If it's working properly I doubt it. Pull the short "accordian" hose off from between the airbox and the Throttle body. The prethrottle is right there in front. If it is returning to full WOT then it's not robbing you of any power. If it's sticking in the middle somewhere then lubricate till it returns to WOT. Assy is the reverse of dissassy. LOL.

sounds good ill check tomorrow

[94530inh]

I already replaced that cable, no change. Could it be the box where the cable connects that is faulty? I even replaced the intake manifold with a different one to see if that solved the problem. Either way its pissing me off! I want my bimmer back the way it was before I decided to tackle a small issue which caused a host of problems. I'm gunna see if I can get that pre-throttle box from the local bmw junkyard and swap that out. I'll check all my sensors too on the wheels. My trans could be shot. 211k on that glass POS.

Is there a way to adjust how early/late the shifts are?

Either way, i'm gunna fix it. This car isnt going to get the best of me.

[Mutinus]

Are you sure you are looking at the prethrottle? The Cruise control "box" is just above the prethrottle servo motor which is more like a cylinder than a box. Before you change anything have you checked what codes the computers are throwing? That could help too.

[Scott 94530I]

My transmission did the same thing after an intake change, but I do not have ASC. My fix was to change the trottle position switch. This fixed the shifting problems. I was only getting an intermittent check engine light. A ten minute job fixed my trans. shifting problem and gave me 8 more mpg.

[94530inh]

wheres the TPS Switch?

[m60b30530i]

My transmission did the same thing after an intake change, but I do not have ASC. My fix was to change the trottle position switch. This fixed the shifting problems. I was only getting an intermittent check engine light. A ten minute job fixed my trans. shifting problem and gave me 8 more mpg.


is this on top of the throttle body could any one post a pick i think after my swap i screwed up the connections with the tps and the asc sensor ( maby im not sure ) im only guessing because my car is idle high ( 1,000rpm) :shifty