Strange MPS issue, Lew's car Options

[914itis]

I am helping Brian with Lew's car. As most of you may know, it is a 2056 with djet.
The car was running fine, he drive it to CT one day and when he came back he noticed that the MPS was hanging. The car starts to run on 3 cylinders with #4 not firing. We checked for spark and injectors they are all fine, but if you remove spark wire #4, it had no effect.

The strange thing is if you elevate the mps about 6 inches up, it's all fine, even that 4th cyl works. All the electrical wires on the unit are fine

(IMG:style_emoticons/default/confused24.gif) ?

Dies the 2056 uses 1.7 or 2.0 MPS?

He would like to make it to Hershey.

[Dave_Darling]

One curious thing that I found--the MPS can be sensitive to shocks and sometimes even to orientation. It is an electro-mechanical device, and the core inside it can be moved by external forces and change the mixture.

I found this out by accident with the engine idling while messing about with the MPS mounting--the sensor fell down onto the engine tin, and the engine hiccupped when it hit. Naturally, I tried it a few more times, and tried jarring it a few other ways. It was most sensitive to being hit on the end.

That part was what led to the realization that the core could be moved relative to the windings by thumping on the MPS body...

--DD