3.2 FPR fuel pressure regulator died. Ran lean for some time, how cooked am I?

[thisisgoodnews]

Engine fully rebuilt (stock internals, SW chip, Fabspeed exhaust + cat bypass) this past spring at a reputable aircooled Porsche specialist shop. Everything went well for 3k miles. Went for a last autumn ride before winter hibernation. Made some power runs up until the redline and noticed unstable power delivery at around 4-5k rpm, difficult to reach redline. Repeated several times, 4/5 runs were bad, 1/5 was ok. Scratching head.

At home, did some diagnosis, checked the FTO switch, appears to be working. Disconnected O2 sensor, went for another drive, pressed harder, no changes.

Couple of days later, went for another, now calm, highway drive. Now notice, that power delivery is unstable even at lower rpm, difficult to climb uphill ant 2nd gear at 3k rpm, slight vibrations noticeable when climbing uphill.

Left it at the shop. Shop reports low fuel pressure, FPR and diaphragm damper needs replacing (was not replaced during reassembly). Makes sense.

Now, it is obvious, that it wasn't getting enough fuel, thus running lean. Am I correct guessing, those vibrations could been engine knock? How screwed am I doing between 120 and 180 miles, since noticing first symptoms? Reading horrible things, high combustion temperatures and oil washing down by unburnt fuel. Oil temperature never went above middle mark.

Besides the compression test, what else should I be looking at? I realise, this did nothing good, but how likely I (badly) damaged this 3.2 engine?

Also, show me your most discreet AFR gauge installations.

BONUS pic as a thank you for attention.

[proporsche]

If the shop said you need the FPR have you or them replaced it yet?
Also do you have CAT or straight pipe?
Ivan

[boyt911sc]

What are the fuel pressure readings (with and w/o vac) with just the FP running? This is a simple test that will determine the condition of your FPR. To test run your Carrera 3.2 fuel pump, bridge fuses #16~#17 (counting from front bumper). Do not replace parts unless tested and confirmed defective.

Tony

[thisisgoodnews]

Originally Posted by proporsche

If the shop said you need the FPR have you or them replaced it yet?
Also do you have CAT or straight pipe?
Ivan

New parts are yet to arrive and to be replaced. As for CAT, it has been replaced by pre-muffler cat-bypass pipe, which is what you probably call straight pipe?

Originally Posted by boyt911sc

What are the fuel pressure readings (with and w/o vac) with just the FP running? This is a simple test that will determine the condition of your FPR. To test run your Carrera 3.2 fuel pump, bridge fuses #16~#17 (counting from front bumper). Do not replace parts unless tested and confirmed defective.

Tony

Fuel pressure has been tested by the Bentley manual procedure. With engine running and it showed just over 1.5 BAR. Disconnecting vacuum did nothing and pinching the return line rapidly increased the pressure. All this point to the FPR.