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.

[JeffBowlsby]

Those exposed wires in the harness concern me. Brittle or cracked? Is that red wire to the TS2 or is it added to the harness?

The 2.0L MPS has a spacer ring that the 12.7L MPS do not have, which allows greater diaphragm range and adjustability...a 2056 adjustment is at the limit f the 2.0L MPS range.

That is a rebuilt MPS...not one of the new Tangerine diaphragms...all bets are off on how it performs. All MPS with new diaphragms need to be calibrated with an exhaust gas analyzer, there are too many variables to determine a single calibration for every engine, even the factory calibrated every MPS to the specific engine. I have found Brad A's published calibrations are lean, I always must richen them up.

[Bleyseng]

Those exposed wires in the harness concern me. Brittle or cracked? Is that red wire to the TS2 or is it added to the harness?

The 2.0L MPS has a spacer ring that the 12.7L MPS do not have, which allows greater diaphragm range and adjustability...a 2056 adjustment is at the limit f the 2.0L MPS range.

That is a rebuilt MPS...not one of the new Tangerine diaphragms...all bets are off on how it performs. All MPS with new diaphragms need to be calibrated with an exhaust gas analyzer, there are too many variables to determine a single calibration for every engine, even the factory calibrated every MPS to the specific engine. I have found Brad A's published calibrations are lean, I always must richen them up.

Early 1.7L MPS's have a WOT stop ring cast in the cover while 2.0L and late 1.7L MPS's don't. You need all the adjustment you can get for a 2056 using a exhaust O2 meter for the calibration. Using a stock 037 MPS will help get you closer but that's a rebuilt one so it's calibration is suspect IMHO.