[JK-81SC]

Originally Posted by Mike Stanko

So it sounds like the diaphragm in your fuel accumulator was leaking and you weren't holding fuel pressure for a warm restart. Did you verify that fuel leaked out of the fitting on the spring chamber end of the accumulator?

Yes. I took the fitting off the bottom of the accumulator, and a lot of fuel poured out. A clear sign of a diaphragm that had a hole in it.

Did you measure the system pressure vs. time before and after replacing this item? What did you find?

I measured the fuel pressure after replacing the diaphragm, and the pressure held according to the specs in the Bentley manual. I didn't measure the pressure before I replaced the accumulator, but I'm sure the pressure would have dropped to zero very quickly.

My fuel pressure was out of range on the temp vs. pressure graph. I ended up pulling the WUR and doing a modification to allow me to adjust the pressure with a screw and a nut. If you decide to do this it's easy. Here's a sketch some else posted from years ago. I used a socket head cap screw instead a set screw.


The pressure is adjusted by driving the pin down with a hammer, or pulling it up with the nut. I had to whack pretty hard on the pin to get it to move, and it's hard to get it to move a tiny bit. With the mod, you can dial in the exact pressure. Just hold the screw in place with a hex wrench and turn the nut to pull the pin up.