Chasing my tail, need help badly.

[blue62]

Originally Posted by Luckyman01

I thought so as well, however I wondered if pump could be failing, IE not enough pressure.

Does the DME or something check for enough pressure.

The current to the relay under the dash is present!

When you turn the key on the fuel pump pressure pressurizes the fuel rail with fuel so the engine can be started.
So there is a Spec. for fuel pressure at the fuel rail with key on engine off.
There is also a fuel pressure Spec. for key on engine running.
Then there is a Spec. for fuel volume.
They are all listed in the Bentley book.
Checking Specs. is what should be done before removing and replacing parts.
That is part of proper diagnostics.
It also saves lots of time and money.

I doubt that the DME checks fuel pressure.
Most likely fuel pump faults are triggered by electrical failure.

Low fuel pressure would show up in other ways such as misfires or lean conditions seen by the O2 sensors.

[Starter986]

Originally Posted by blue62

When you turn the key on the fuel pump pressure pressurizes the fuel rail with fuel so the engine can be started.
So there is a Spec. for fuel pressure at the fuel rail with key on engine off.
There is also a fuel pressure Spec. for key on engine running.
Then there is a Spec. for fuel volume.
They are all listed in the Bentley book.
Checking Specs. is what should be done before removing and replacing parts.
That is part of proper diagnostics.
It also saves lots of time and money.

I doubt that the DME checks fuel pressure.
Most likely fuel pump faults are triggered by electrical failure.

Low fuel pressure would show up in other ways such as misfires or lean conditions seen by the O2 sensors.

Good advice, Blue. Thank you.

I purchased the least expensive compression/fuel pressure kit from HB months back. I did try to hook it up to the Schrader valve recently, but it didn't conain the proper fittings.

I'm checking fuel pressure so infrequently (have never) I'm hoping you could make a HF recommendation for a kit that will work with the 986, and moderately is priced. Thanks!

[Luckyman01]

I am going to enlist help to track voltage from the "in" side of the fuel pump relay and see if I can learn something.

This forum is full of great folks, I love the info laced with patience and kindness.

[Gilles]

Originally Posted by Starter986

Good advice, Blue. Thank you.

I purchased the least expensive compression/fuel pressure kit from HB months back. I did try to hook it up to the Schrader valve recently, but it didn't conain the proper fittings.. Thanks!

Regarding the Fuel Pressure Tester.. if you have an Autozone nearby, you can 'borrow' the fuel pressure tester' and when you return it you will get your deposit back.. 😁

[Luckyman01]

I tested at the plug at the top of the fuel tank. The Green wire was where I looked.

[Gilles]

Originally Posted by Starter986

I'm checking fuel pressure so infrequently (have never) I'm hoping you could make a HF recommendation for a kit that will work with the 986, and moderately is priced. Thanks!

One time I required a fuel pressure tester for my 987CS and I rented a tester from Autozone that had the correct adapter, you leave the deposit and a refund as soon as you return the tool, you can't beat that.. :-)

PS: I also have a couple of tools that I never returned and ended owning them..