gbgastowers

Still have not figured out my low power under load problem. I noticed low fuel flow to some of the suspect cylinders(spark plugs were clean there or showed no burn marks)by removing the fuel line to the injectors and bridging the pump.
I removed and cleaned out the fuel distributor(wasn't dirty).When I removed it I noticed the o-ring that seals it to the air body was pinched and broken and thought this was my problem. No such luck. I checked the fuel pressures finally and came up with system pressure 4.75 bar/70 psi (should be 67-75 psi:OK)and the cold control was 1.8 bar/26 psi (should be 17-44 psi:OK). A problem appears to be that the control does not rise when the WUR electrical is plugged in. It stays at 26 psi and it should warm and rise to 41 to 46 psi. So this would result in too low control pressure which is keeping it too rich when the engine warms. It looks like I need to push the regulator pin
inward in the WUR body to increase control pressure or switch out the WUR from my used selection and see what happens. This is all very confusing so let me know if I am wrong.http://www.youtube.com/watch?v=G1BGXz257Oc&feature=player_detailpage#t=25s<object style="height: 390px; width: 640px"><param name="movie" value="http://www.youtube.com/v/G1BGXz257Oc?version=3"><param name="allowFullScreen" value="true"><param name="allowScriptAccess" value="always"><embed src="http://www.youtube.com/v/G1BGXz257Oc?version=3" type="application/x-shockwave-flash" allowfullscreen="true" allowScriptAccess="always" width="640" height="390"></object>http://www.youtube.com/watch?v=k6Vxp...etailpage#t=1s

http://www.youtube.com/watch?v=k6Vxp...etailpage#t=4s

gbgastowers

I am definitely on to something here. I tried another WUR and when I plugged in the electric from cold(30psi) I watched it shoot up past 50psi(too high). So this one shows the control pressure too high. The car ran even worse with this WUR so I drove the regulator pin in a little on the original WUR and put it back on the car. The warm control pressure was then 12psi which was lower than before I drove the pin in. This was surprising because I thought the pin goes in to raise control pressure. I went ahead and drove the car and it seemed to run better but still not right. This is the original WUR that the heating element does not work in. My mind is going crazy trying to figure this out but I am seeing big changes which is encouraging.

gbgastowers

Just went for a long test drive. I would say I am at 80% power now across the range which is up from the 40% I was at yesterday.

I just want to say thanks to all my friends who have chimed in to help me out on this thread topic.....

Landseer

I'm reading, but mute because I don't know **** about CIS.

Am only wondering if I have to lend you a car to run up the mountain or not.

I haven't seen any CIS gurus post all day on Rennlist but have been hoping they would.

gbgastowers

As they say:" I know just enough about it to burn up the car".

Yeah-believe me, being able to get to SITM and not embarrass myself too much along the way is on my mind.

jpitman2

I would try swapping the bimetallic heater assy from the alternative unit that worked into the original wur, OR, open the alternative, and flush it out to remove the reason the pressure rises too high. 50psi is high, but not too far out of the ball park, and I would bet its caused by crud and deposits inside - gauze filter etc.
Moving the pin IN pushes the fingers down on the spring, and allows more pressure to bleed out the return line.
jp 83 Euro S AT 53k

gbgastowers

Thank you so much. I need all the help I can get. I have been putting this off for 6 months.


"Moving the pin IN pushes the fingers down on the spring, and allows more pressure to bleed out the return line." <does moving the pin downward raise or lower control pressure?

tailpipe

I have drilled and tapped my plug and put a bolt and nut on it so I can adjust the WUR on the fly. To move the plug down unlock the nut up against the WUR and tap the bolt head down to move the plug upward just tighten the nut agaist the WUR you should check you measurments cold if you can.

gbgastowers

This page really helps. It explained to me the counter pressure on top of the fuel distributor piston. I did not know what was happening there. It's apparently very important and possibly worth 175 HP.


http://porsche928forums.com/viewtopi...=543&hilit=wur

gbgastowers

I have 3 working WUR's now cleaned and functional. I replaced the heating element on the original using one that had 23 ohm stamped on the green element part. The one that was bad had 30 ohm on it but hopefully it won't matter much. I will post the warm results later. I am still experimenting. The big spring have different paint markings on them in black.