CFR MPS rebuild, Copy of instructions Options

[Ron914]

I needed to rebuild my MPS but Chris Foley is out of the kits due to no longer having a supplier of the BE-CU diaphragms . I was lucky enough to have a member here offer to sell me his spare parts kit from Chris (Thanks Tom). His kit did not have the instructions with it so I am wondering if anyone has a copy of those instructions?

[Ron914]

After reading a bit of Paul Anders MPS Diagnosis I am not sure if I want to tackle this one on my own ,at least I need to read the rest of the documents but I will say this gets a bit deep when compared to Chris's instruction sheet . In the Anders documents it tells you how to test the MPS.Anders says at 10inhg acceptable leak down is < 5inhg in 1 minute so I tested mine again out of the car and made sure my connections to the Mityvac were tight and I got 6.5inhg in 1 minute so maybe all I need to do is tune it . Then again I am going to read more on this before I decide to tear the MPS open .

[JeffBowlsby]

After reading a bit of Paul Anders MPS Diagnosis I am not sure if I want to tackle this one on my own ,at least I need to read the rest of the documents but I will say this gets a bit deep when compared to Chris's instruction sheet . In the Anders documents it tells you how to test the MPS.Anders says at 10inhg acceptable leak down is < 5inhg in 1 minute so I tested mine again out of the car and made sure my connections to the Mityvac were tight and I got 6.5inhg in 1 minute so maybe all I need to do is tune it . Then again I am going to read more on this before I decide to tear the MPS open .

Not sure where that leakdown tolerance criteria originates, seems made up, which coming from Brad A, I seriously doubt he made up. D-Jet can work OK with a slight leakdown because of the way intake manifold vacuum pulses maintain a vacuum level but a leak is a leak which richens the mix and richness increases with the time a leakage increases. The EFI Associates MPS rebuild data I have requires checking leakage at 5 step values up to 18 in/Hg, with no allowed leakdown. Its also near impossible to calibrate the MPS with any degree of precision when the vacuum gauge needle is always moving.

Chris' method of 'measure twice cut once' is the machinist way of attempting to replicate the original calibration without using an inductance meter or WB02 sensor. Hats off to you Chris, its a creative and efficient solution. It assumes the current calibration is correct to the factory original specs or was previously set accurately to your engines current needs. It seems like a reasonable way to get you close enough to fine tune it with the WB02, but I have not tried it.