1991 964 C2 Fuel Pressure Regulator Replacement
05-23-2014, 11:34 AM
#16
onceover- I was having warm start problems and a mixture of other weird power issues - small occasional backfire when accelerating, random power loss, etc. Progressively got worse. I changed or checked everything, ISV, O2 sensor, DME relay, DME reset, MAF sensor, codes, etc. Then I attached a fuel pressure gauge and noticed the pressure dropped to zero with a couple seconds when I shut the pump off - it should stay up for 20-30 minutes. I pinched off the supply line at the pump and the pressure still dropped - indicating the check valve in the pump was not the problem. Then I pinched off the return line on the FPR and it still dropped. That meant it had to be draining into the vacuum line - and sure enough, when I pulled it off, fuel leaked out. Then I turned the pump on and got a geyser out of the small vacuum port on the FPR! That was my diagnostic process, for what it is worth!
05-23-2014, 03:40 PM
#17
Nordschleife Master
It's toward the center, there are 3 small lines, I believe it's the center one. Look for the FPR under the middle of the intake assembly, you should be able to see the line exiting it and follow that up to the center piece on the intake.
05-23-2014, 06:10 PM
#18
Rennlist Member
Thread Starter
onceover- There are 3 large fuel lines attached with flare nuts - don't touch those! There is one small vacuum line in the center of the FPR facing the rear of the car and can be tugged off with your fingers. You will have to remove the plastic fan duct on the the left side (not the fan motor itself) of the engine. Then you can look under the intake and see it. It's tight, but I was able to get my fat hand in there and pull off the rubber vacuum tube elbow. If you see fuel drip out of the FPR vacuum fitting - that is bad! If you don't see fuel, have someone activate the pump by jumping the DME relay while you watch to see if fuel sprays out. Again - fuel is bad if it leaks from the vacuum line fitting!
There is a photo here: http://i377.photobucket.com/albums/o...psa357f099.jpg
It's the round object on the right side of the image with a rubber hose going to it (that is the hose you will pull).
There is a photo here: http://i377.photobucket.com/albums/o...psa357f099.jpg
It's the round object on the right side of the image with a rubber hose going to it (that is the hose you will pull).
Last edited by flypfi; 05-23-2014 at 06:27 PM.
05-23-2014, 06:29 PM
#19
Nordschleife Master
You don't need to go through all that trouble to disconnect it at the FPR, just disconnect it at the intake while the car is running and watch it for a minute or two to see if it burps out fuel.
05-24-2014, 03:31 PM
#20
Rennlist Member
Thread Starter
I finished the project in about 5-6 hours. All went well. The car runs so well, I had forgotten what it is what like to drive a perfectly running 964. The FPR replacment fixed ALL of my problems:
Cold Start
Hot Start
Random power loss
Poor idle
Overall poor running and performance
When I pulled the right intake manifolds, about 6 ounces of fuel poured out. Bad news. It was all running backward into the intake from the vacuum/pressure side of the FPR. It was not a fun job but well worth the trouble. I took many photos and will post a step by step if anyone is interested.
Thanks for everyone's help!
Cold Start
Hot Start
Random power loss
Poor idle
Overall poor running and performance
When I pulled the right intake manifolds, about 6 ounces of fuel poured out. Bad news. It was all running backward into the intake from the vacuum/pressure side of the FPR. It was not a fun job but well worth the trouble. I took many photos and will post a step by step if anyone is interested.
Thanks for everyone's help!
Last edited by flypfi; 05-25-2014 at 12:48 AM. Reason: Correction
05-29-2014, 11:47 PM
#24
Just checked the regulator and sure enough there was fuel in the vacuum line.
I tried to trace the line back to the manifold to disconnect it more easily but it splits off in a few directions, maybe this is a MY89 thing.
Snapped a few pictures in case anyone else wants to check their FPR, it's actually quite easy to remove the line right off the regulator once you realize you can access it from under the blower fan.
You can see it in the middle of the first photo, and the second is a close up. Just pull that vacuum line off and check for fuel.
Where do people suggest getting the regulator from? ECS Tuning wants $180 for it.
Also, can someone confirm that the correct part number is: 92811019804 ?
I tried to trace the line back to the manifold to disconnect it more easily but it splits off in a few directions, maybe this is a MY89 thing.
Snapped a few pictures in case anyone else wants to check their FPR, it's actually quite easy to remove the line right off the regulator once you realize you can access it from under the blower fan.
You can see it in the middle of the first photo, and the second is a close up. Just pull that vacuum line off and check for fuel.
Where do people suggest getting the regulator from? ECS Tuning wants $180 for it.
Also, can someone confirm that the correct part number is: 92811019804 ?
05-30-2014, 11:37 AM
#26
Former Vendor
05-30-2014, 06:12 PM
#27
Rennlist Member
Thread Starter
onceover- I got mine at Pelican for $166.75 USD. It is the OEM Bosch replacement.
Here's the link: http://www.pelicanparts.com/catalog/..._pg2.htm#item3
Here's the link: http://www.pelicanparts.com/catalog/..._pg2.htm#item3
03-21-2016, 07:00 PM
#29
Track Day
Join Date: Feb 2016
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
Random power loss
Poor idle
Overall poor running and performance
Poor idle
Overall poor running and performance