With my new lease on driving pleasure (S50 swap) came a new set of problems. One of them is the throttle sticking upon initial press of the throttle. It moves smoothly throughout throttle application, but it just sticks upon initial push. If I had to describe it on a scale of 0-100, I would say it like this: It sticks in positions 1-3 and the rest of the range is smooth operation. Sometimes it sticks a little more than other times, sometimes a little less, but almost always I end up revving the engine up having to really slip the clutch to prevent a tire-smoking launch. Tonight, I bought a can of throttle-body cleaner and sprayed the springs and the throttle body opening very well, while moving the throttle position open and closed repeatedly. While it did improve a very little bit when I got back in the car and tried it, it stiffened back up again after a few minutes. I sprayed the points where the throttle body flap contacts the housing and I also sprayed the series of springs outside of the housing. I even sprayed the throttle cable for good measure, but after a few minutes, nothing worked and it was sticking just like the way it did before. I had this problem a while back when the M20 was still in there. It turned out to be a frayed throttle cable, and that stuck in all ranges of operation. I replaced the cable and it was smooth as silk, but this cable (from an E34 525i) isn't frayed in any way, and operates freely. Would else could be causing this? Would this warrant another throttle body?
I don't know how to unhook it; wouldn't this be the same as manually moving the "lever" the throttle cable is attached to? I did move it manually but it's still getting stuck. I'll figure out how to remove the cable tomorrow when I have a working flashlight (i.e. the sun).
Open the throttle body and you can pop the cable out. A light may help. I changed my throttle cable and it was like night and day. A fix that you notice right away.
I really hope it's not the throttle cable. The last time I went to change my throttle cable on my M20, I spent a good part of 2-3 hours trying to get the old one out. I think Marshall heard me saying "THAT STUPID PLASTIC PIECE" one too many times over the phone. Remember that M?
Screwdriver and hammer. It came right out. Of course the screwdriver also pierced the firewall. Hammer again. Fixed. For me it was easier to get to the cable by removing my seat.
My firewall got screwed as well, but since it's already screwed I'm sure it won't be too difficult to get it out again. Heck, it had to come out again during the swap, so it can't be too difficult the 3rd time around.
On : M20 engine. Previous owner used regular gas, the airfilter was..yuck..long story short, i had dirt around the TBI valve and edges (no idea how its called. Drossel in german).(3mm thick! so the dirt from the TBI walls sticked to the valve. TBI out, Hoppes'9, round brush, and clean. (2$ solution),plus gasket . replace TBI (more then 2$-solution) caliper cleaner afterwards and lighter fluid to wipe it clear. however, the E30 it is, not sure if that applies to yours too,..i had to adjust around the throttle cable as the Throttle position sensor wasn't actuating which was fixed by readjusting the cable. the sensor..well switch ..didnt need adjustment.