My W108 project in only moving forward.........literally! Please help!

[theskiflyer]

So I bought my first car in Sept. (W108 4.5) After some work we got it going well. It has been basically problem free up until about 2 weeks ago. Now when the car is warmed up and I shift into reverse the car stalls. And it WILL NOT start again till it has fully cooled down.

Any suggestions?

Thanx Alot,
Taylor

[Mike D]

Just a shot in the dark but how are your engine mounts? It's possible you have a suspect electrical connection which gets "tweaked" when the engine shifts position. I'd say fuel line but if it occurs immediately then I lean towards electrical.

[Shab]

Perhaps the dreaded neutral safety switch on the tranny. It's almost always been my misfortune that 2 electrical faults are involved. My 4.5 used to do the no start till cool routine also.

[Tomguy]

Poor hot starts is typical of either a faulty aux air valve or maladjusted throttle plate, throttle position sensor and/or air speed screw. Make sure the throttle plate is closing completely, and make sure the throttle position sensor knows it is. After ensuring that, try backing the air speed screw off a half to a full turn (counterclockwise) to raise idle speed and prevent stalling and help hot starts. You may need to adjust the idle mixture AND the air speed screw might actually have to be turned in, BUT the faster idle will help prevent stalling at least. My 4.5 starts hot and cold in less than one half a revolution.