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Posted by: DavidSweden Mar 21 2015, 02:35 PM

I am rebuilding my motor 76 2.0 and checked the MPS today. It sucked on it and it does not hold a vacuum, from what I have read it should hold a vacuum. My engine was running before the rebuild and I don't see how it could of got damaged when I removed it.

Do I need to replace it?

Posted by: Racer Chris Mar 21 2015, 02:40 PM

The diaphragm is bad. The engine will run much better after you replace the diaphragm.
I have what you need.
http://www.tangerineracing.com/engine.htm

Posted by: DavidSweden Mar 21 2015, 05:00 PM

Chris and anyone else who has the time to help

I have a couple of newbie questions regarding the MPS diaphragm replacement.

Is the diaphragm replacement fairly straightforward and how easy is it to re-calibrate the MPS?

If anyone who has done this can give me some advise I would be grateful

Thanks

Posted by: boxsterfan Mar 21 2015, 05:27 PM

http://members.rennlist.com/pbanders/manifold_pressure_sensor.htm

Load of info here. This is the best reference for D-Jet out there.

Posted by: BeatNavy Mar 21 2015, 05:32 PM

Chris provides very good instructions. I did it in about an hour and half one evening. Also, you don't HAVE to install the adjustment piece. You can do only the diaphragm replacement. I also have pictures I can share of the process if needed. It's not hard - go for it!

Posted by: DavidSweden Mar 21 2015, 05:53 PM

Rob,

Yes I want to go for it, I don't understand what do you mean when you say "you don't HAVE to install the adjustment piece"?

Can you please explain, thanks

Posted by: 76-914 Mar 21 2015, 05:55 PM

Chris sells the tool as well. I highly recommend buying it. It's very frustrating when both limiters turn. Very, very small adjustments make big differences. Count the number of turns when removing.

Posted by: BeatNavy Mar 21 2015, 05:58 PM

Chris' MPS kit comes in two types: Diaphragm repair and MPS tuning. You can just buy and install the diaphragm repair kit if that's all you want to do. It's pretty simple. If you want to make your MPS easily adjustable, buy the MPS adjustment option. You can see the options on the Tangerine website.

Posted by: Racer Chris Mar 21 2015, 06:22 PM

If you follow the included directions to replace the diaphragm and seals included in the kit - the MPS will operate as it did before the diaphragm failed.



If you replace the stock stop screw with the one included in my tuning kit, and you install a wideband air/fuel meter in your car, its fairly easy to improve the overall tuning of your engine.

Posted by: DavidSweden Mar 22 2015, 02:43 AM

Chris and everyone
Wouldn't a wide band air/fuel meter be overkill for my stock engine (what do they cost, I am a poor European with an expensive hobby). Could someone PM me Tangerines diaphragm installation instructions?
I have read the strip down and tuning instruction for the MPS on Rennlist it seems pretty straightforward. However some equipment is required a vacuum pump an LCR meter,.
The LCR meter recommended on Rennlist costs about $350the the cost of these products plus the diaphragm kit make it cheaper to buy a reconditioned unit From AutoAtlanta, although this would be not as much fun as repairing the unit myself.

Question: If I replace the diaphragm do I need to calibrate using a LCR meter or is there a workaround?

Thanks

Posted by: Racer Chris Mar 22 2015, 03:24 AM

An inductance meter isn't necessary.
The instructions explain how to assemble the unit to perform very closely to how it was built at the factory.
A 6" dial or digital caliper, or similar measuring instrument, is essential.
If I were you, I would buy the tuning kit along with the repair kit.
Better to have it and not use it, than not have it and wish you did.

I'm going to start offering a rebuilding service soon.
If you prefer, send your unit to me. We will install the new diaphragm and set it up with an inductance meter.

Posted by: BeatNavy Mar 22 2015, 05:48 AM

If you install the adjustment piece then "yes," it is a good idea to have an O2 sensor & A/F Meter. I liked having something else I can "play with" in the adjuster, but if you're just trying to get back to stock then the repair kit is probably all you need.