Another oil pressure gauge question

[Buckeye]

I can't find an answer to my oil pressure gauge problem. When I start the car the gauge goes to 4 for around 10 seconds and then goes to 0 and never moves again. Here are the facts:

-it is a 1987 911
-the oil pressure sending unit was just replaced
-if you disconnect the wire from the oil pressure unit the gauge pegs at 5, just as it should
-the connection to the oil pressure sending unit has been cleaned and tightened up

Any ideas, is it a bad sending unit ?

[proporsche]

Hi Buckeye..It is very possible that your new o p s u... is bad.To test connections ground the wire and you should see the gauge hand go down to zero.If it does ,your cable connection to the front gauge is ok, you could have bad new unit..is it an aftermarket or original spare part you have installed?
If the gauge inside does not response to the wire being grounded possibly bad gauge...
Ivan

[Targalid]

Why did you replace the oil pressure sending unit?

[Buckeye]

The old sending unit was acting strange, it would bounce around from 2-4 without increase the engine rpm. I did a valve guide replacement and I thought while I was in there I would replace the oil pressure sensor as well. With the old oil pressure sender it did not act like it is now. It is worse now than it was before

[Buckeye]

The sender was a new unit

[Flat6pac]

Tighten the clip to the sender, slip a pic along side the slide on metal connector and the plastic housing. It doesn't take much to tighten the connection.
Bruce

[Buckeye]

Thanks I will give that a try