MAP sensor repairers
 

Hi all,
Does anyone know of anyone who can repair MAP sensors from old D Jetronic injection systems?

Mine seems to have lost its sealing. Fails to hold 15"Hg for more than about 5 seconds.

I am aware that iroll motors and Bosch Classic as potentials. Any other solutions are welcome before I start looking at Megasquirt etc [emoji102].

I am in the UK if that helps.

U

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a good used sensor is an inexpensive and easy option

Yes, there are a few on sale. They will be just as old, untested and as close to the end of serviceable life as mine.

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not necessarily.

find a seller that will accept a return and you should be good

In order to make any repair on this you need to know which version you have. Because there are three of them.

Versions one and two have a screw adjustment on the end of them. These use one type of diaphragm. The type three has a plastic cap over the adjustment screw. It uses a different diaphragm.

If yours is original it is held together with four brads. If it is a rebuilt unit it is held together with four screws. Bosch rebuilt a lot of these and sometimes they show up for sale on Evil Bay or elsewhere.

There are two parts to these: The electrics and the diaphragm. I don't know the first thing about the electrics, but the diaphragm will lift right out after you open the case. It has a pinhole which is why it will not hold vacuum. If you can find this pinhole and seal it with some rubber cement you might be OK.

The tough part is finding the pinhole. And don't just seal the hole but treat the area around the hole. Otherwise the diaphragm will continue to tear and you will have to do all of this again.

Seeing you are in UK, you might try contacting Dr. Djet in Germany.

Link here: https://jetronic.org/de/

On Benzworld W107 forum, there has been some discussion about sealing leaks in the MPS . Cushjbc has been experimenting with repairs, https://www.benzworld.org/threads/bosch-manifold-pressure-sensor-disassembly.3049678/#post-17981611

Good Luck.

I have also removed these and found no pinhole. Then I could not get the diaphragm back in as they fit with a bit of precision.

So I used some synthetic wheel bearing grease to lube up the rim of the thing and it slipped back in. This also sealed up my leak as there was no pinhole. It was leaking around the rim.

I then removed it again and treated it with glycerin to renew the seal. And it held.

I do not know if this is a fix or if I just got lucky.

I have also used this trick to renew vacuum trunk actuators for 60s and 70s GM cars.