W108 4.5 Manifold Air Pressure sensor

[GermanStar]

The part is exchange, yes -- core is $50.

[fatshot]

The sensor on my '73 280SE 4.5 only has 4 terminals, #s 7,8,10, and 15. It doesn't have a fifth, or #11 terminal. Does this mean it was replaced with the wrong part at some time? I noticed also that the braided rubber hose to the manifold had no hose clamps on it, and could easily be pulled off the sensor. Also, I am getting infinite resistance between terminals 8 & 10. I guess that this is the reason that the car is running rich all the time and won't pass emission tests. What do you guys think?

[Nutz 4 Benz]

Originally Posted by fatshot

The sensor on my '73 280SE 4.5 only has 4 terminals, #s 7,8,10, and 15. It doesn't have a fifth, or #11 terminal. Does this mean it was replaced with the wrong part at some time? I noticed also that the braided rubber hose to the manifold had no hose clamps on it, and could easily be pulled off the sensor. Also, I am getting infinite resistance between terminals 8 & 10. I guess that this is the reason that the car is running rich all the time and won't pass emission tests. What do you guys think?

Yes,there are only 4 terminals...7,8,10 and 15. If you don't have the hose between the pressure sensor and manifold tight,your fuel control will be incorrect.Throw a clamp on and try an IM again.

The infinite reading between 8 and 10 on the other hand isn't encouraging.I have a sticky D Jetronic and K Jetronic troubleshooting thread at the W116 forum here which may aid you in the future.

[Grubeguy]

Ahhhhhhh, so I checked my spare while watching South Park - should I repeat the test with the spare installed, and the engine running?

[kdm7005]

Hello Grubeguy, would be interested in selling your defective core?

[Grubeguy]

Hmmmmm, dunno. I paid a HUGE sum ($50, I think) when purchasing it off ebay, and it DOES attract the aforementioned predators that suit my purposes ...

Have you an offer? I had actually thought about keeping it myself to test on the running car ...

[alabbasi]

Every time I find a W108 in the junk yard or an Early w116, I pull the map sensor and computer. I'm now up to 7 of each.

Your problem may also be the computer. I thought mine was the map sensor but it turned out to be the brain that made it run so bad.

If it runs rough at idle, I think it will be the brain and not the map sensor.

[Grubeguy]

OK, so does anyone have a spare, working brain for sale?

[GermanStar]

An optimist! We have 'em, but you don't want to know......

[Grubeguy]

Don't want to know the price? If you can guarantee that it works, I'd entertain notions ...