Testimonial: MPS rebuild kit install from Tangerine Racing

Discuss with fans and owners of the most luxurious aircooled sedan/wagon that VW ever made, the VW 411/412. Official forum of Tom's Type 4 Corner.
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Testimonial: MPS rebuild kit install from Tangerine Racing

Post by aircooledtechguy » Thu Jun 27, 2013 7:37 pm

So I finally had a reason to purchase one of the Manifold Pressure Sensor (MPS) rebuild kits that Tangerine Racing recently started producing and selling. A client had a low mileage 914 2.0L that had a busted diaphragm. This is about the only reason these things go bad and is the Achilles heel of the D-jet system.

I bought the basic kit which just has the replacement diaphragm and the seals since I have a shop fill of tools. I would recommend a DIYer to get the complete tuning kit as it will ensure you have everything you need.

Here’s a link to the page:

The directions provided are complete and really make it idiot-proof (I did it; so can you).

The whole process took about 30 minutes to complete and now all I need to do is do the final adjustment out on the car when the client brings his car back with my loaner MPS.

Chris’s products are the industry standard in the Porsche world and this rebuild kit is no exception. If you have a bad MPS and want to go back to stock D-jet EFI, I highly encourage you to pick-up one of his kits.

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Re: Testimonial: MPS rebuild kit install from Tangerine Raci

Post by dawie » Mon Jul 01, 2013 3:15 am

Wonder why the diaphragms go bad? Just old age or maybe caused by a severe backfire?

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Re: Testimonial: MPS rebuild kit install from Tangerine Raci

Post by raygreenwood » Mon Jul 01, 2013 8:06 pm

Backfiring is not capable of hurting the dipahram really because of the outer full load stop. Two reasons cover alsmost all eventualities
1. metal fatigue from flexing does about 1/3 of them in.
2. Corrosion around the outer edges does most of the rest of them in.

I suppose there is a third...turning the center screw in or out way too far but that would be exceedingly rare....as just a bit too far either way and the car will not even start so the screw will not remain that way for long.

Its good that someone else has started making these. I made a press mold and have made a few excellent ones for private use, but connecting them to the center section like factory is not for the lazy. I use a few mods to teh center assembly...and a thin snap ring sealed with a fine bead of RTV.

I just have not been in the position with all of my projects to manufacture them in mass for everyone else.

To those who replace your diaphram..be very careful of the slight differences in the locations of the spacer plate/ring between the gasket, body and dispahram. Note its location. It affects the adjustment of the inner load stop (that would be the adjustment that requires the hollow 7mm allen key).

The differences in the placement of that spacer ring are the only significant differences between an E model from a VW 412...and the 039 from a 2.0 914. You can use either in either car...just mind that spacer and readjust. Ray

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