Fuel Pressure Regulator (staring hesitations)

[Germanator]

I finally found the cold start issue I had with my 1988 911. From this forum I got many tips and suggestions what to look out for. At the end I changed a lot of things. I even got my DME rebuild by Ingo.

I did always suspect it might be the FPR, however, after reading all those horror stories about the difficulty in getting this thing out - changing it wasn't high on my list.

Well, a day before Xmas I decided now or never, and to my surprise, it was really easy. I didn't even have to cut some wrenches (as some suggested). After I removed the blower motor, and the sensor plugs to get better access it was really easy. What helped was a mirror in the back to help checking things before I used the 19 mm wrench to open the fuel lines. The FPR is mounted on a bracket which is attached with three 10 mm screws that are easy to get off. When the bracket is out, I used a 24 mm wrench to remove the FPR.
The time to get the FPR out was ca. 30 min (max), which did not include removing the heating blower.

Putting the new FPR in was a bit more work since putting the screws back is a bit tedious (small mirror helps), but not a difficult job.

I cut the FPR open to see what is going on in there. You can see the membrane looks old and seem to have cracks. I put some water on top and applied some slight pressure and I could see air bubbles coming out.

Hope this will help other guys out there with similar issues but are afraid of the fuel pressure regulator removal.

Happy New Year everybody
J

[DRACO A5OG]

Good Job! You got lucky that PO did not over torque it. If OEM it would be a SOB to remove :-)

[ALXinNZ]

Did your car have any other symptoms. Like loss of power or a feeling of being flat ?. Great post

[scarceller]

If the membrane was cracked you most likely had raw fuel being sucked down the vacuum line and introduced into the intake just below the TB. This would cause rich running conditions most notable at idle or high intake vacuum.

[Germanator]

When I first checked the vacuum lines last year I didn't notice any fuel - but I guess it depends on the timing... (back then it was little leakage).
Yes, when the engine finally started, it was idling rough for a 30s, and then engine ran great afterwards, with no loss of power.

Now, it is really obvious what was the problem! And I should have changed the FPR first!
But at least I know, I got a new fuel pump, a rebuild DME, a new .....
Not much to fail for a while. Maybe I should change the fuel pressure damper as well?

I am glad I didn't give up looking for the problem. Bringing it to the mechanic would have cost me more than all the new parts I replaced during the search. In addition, I know my car now even better...

Cheers
J

[911 Rod]

Did you notice it acting up when it was damp out?