thomas682

1979 930 - what would cause the factor boost gauge to spike to 1.0 bar as soon as I turn on the ignition. The gauge continues to read 1.0bar after being started and even while running. Sometimes it jumps around when on boost or at idle? Sometimes it drops down to .6 to .4 when on boost? Odd?

Where should I start trouble shooting?

Any suggestions for sourcing a barb fitting for the back of a Clock location VDO boost gauge. Am I correct in attaching the hose to the metal fitting at the brake booster location - adding a "T" fitting with 3/8" ID hose?

Thanks in advance for sharing your wisdom.

nathanUK '81 930 G50

Sounds like a loose connection.

I think Stephen sells the fittings to plumb in the gauge into the booster hose.

911rudy

If the gage is working properly it should deflect fully when you turn on the ignition. If it does this and then you take the pressure gage sender wire and groung it it should return to zero. If it does both of these things then it is a bad sender. If it dosen't work like this, it is a bad gage.
Rudy

WERK-I

Make sure the sender is properly grounded. Check your resistance between sender ground on the IC and chassis ground. You should have less than 1 ohm resistance between the two. If you don't, find out where the ground is broken.

Dave
'85 Factory Slantnose 930