I have traced my driveability problem (long story) to a cylinder head temp sensor that is intermittentently open. The current sensor has the 270 Ohm resistor in series which I thought was only for the 2.0 but my engine is a 1.7.

What I need to know is what sensor part number do I need and should I keep the resistor. My ECU is a 0280000015 (022906021B) which I believe is correct for my engine. My MPS is a 0280100019 (022906051A) which I'm not sure about but seems to work OK.

Any recommendations?

Thanks,
Brian

You should find what you're looking for on Brad Anders D-jet page

Is the 911 still for sale? that color combo is sweet

Head temperature sensor 1970 thru 1974, 311 906 041 A

Pressure Sensor 1.7, 022 906 051 E

So is it a problem to stick with the MPS I have? I did not see it listed on Brad's site. Is it for a non Porsche application?

Is the resistor possibly a DPO bodge to compensate for the wrong MPS.

Should I get rid of the resistor with the 041A sensor?

Thanks

Yes, the 911 is still for sale. It's actually nicer now - I've fixed several things. I'm about to start agressively marketing it and through it on ebay if it doesn't sell.

Know anyone in the market????

The Bosch part number for your cars pressure sensor should be: 0280100049

From what I understand, the resistor in line with the head temp sensor make the engine run richer. If your engine is running too rich then I would remove the resistor. However, if your car is running too rich, it more than likely is a bad (or the incorrect) pressure sensor.

10/69 to 07/71:
Up to 6/70...ECU 0 280 000 007 (VW Pt # 022 906 021..interchange 013 / 032 / 037)
From 07/70..ECU 0 280 000 015 (Por / VW Pt # 022 906 021

CHT ............. 0 280 130 012 ( VW Pt # 022 906 041)

10/69 to 04/70 MPS ............. 0 280 100 003 ( VW Pt # 022 906 051)
05/70 to 07/71 MPS..........0 280 100 019 ( VW Pt# 022 906 051 A..interchange w/ 049 and Pt # ends in 051 E)

08/71 to 07/72

ECU....0 280 000 037 (Por / VW Pt # 022 906 021 E)
CHT.....0 280 130 012
MPS.....0 280 100 041(interchange with 049....VW Pt# 022 906 051 E)

07/72 to 10/73
ECU.....0 280 000 040 (Por / VW Pt # 022 906 021 E..interchanges with 037)
CHT.....0 280 130 012
MPS.....0 280 100 049 (VW Pt# 022 906 051 E)

After 10/73 no more 1.7s were produced. 1.8s began in 11/73

This otta confuse you enough....................

QUOTE

This otta confuse you enough....................

Quite the opposite - that pretty much clears it up. Thanks Ron.

It looks like my ECU and MPS are a correct combo and I need to get an 012 CHT sensor and ditch the resistor.

One handy thing about that resistor, it provided me a "limp home" mode when CHT failed. Just short it to ground and it ran well enough to drive the car. I don't know if this would work on a car that is supposed to have the resistor.

QUOTE (Brian_Boss @ Nov 4 2005, 01:44 PM)

One handy thing about that resistor, it provided me a "limp home" mode when CHT failed. Just short it to ground and it ran well enough to drive the car. I don't know if this would work on a car that is supposed to have the resistor.

I was told by a "rebuilder" of FI parts that if you took a paperclip and hooked it into the CHT lead outta the FI harness and grounded it, it would function like a hot CHT and the car would run....and no, I have never tried it.