Warm Up Regulator my problem?

[78Jason]

What does the Warm Up Regulator (also called the Fuel Pressure Regulator) do at various engine temps?

How can I test this unit to be sure it isn't causing problems in the delivery of my fuel? When I first got the car - it wasn't even hooked up (the vacuum wasn't, the fuel did still go through it), and the car ran what I thought was fine. Obviously its there for a reason - so I hooked up the vacuum again.

[Jim Sims]

You need a CIS pressure tester to properly evaluate if the WUR is working correctly. A defective WUR can be the cause of numerous CIS system problems as can many of the other fuel injection components. If you want to do this yourself obtain a pressure tester and a trouble shooting guide. Cheers, Jim

[78Jason]

Thanks guys -

Noah - when you say "running problem" what do you mean? My problem is high idle when hot, and of course the engine is running - Either way - I've replaced the fuel filter, accumulator, and fuel pump and cleaned injectors. All that has improved everything, except....

It's worth noting that when the timing was retarded (2 deg or less btdc) I didn't have the high idle when hot... it returned to normal when pulling up to a stop light. (but the motor didn't perform as well overall!) When I corrected the timing - idle at high jumped back into my life.

Does that give any more clues to the potential source?

[Kemo]

Jason,

you went down the same road i did...i was very hesitant to replace the WUR due to the price. Before i solved my issues, I had changed the wires, plugs, cap and rotor; in addition to all the things you have done, sans fuel pump. The most noticable improvement came from replacing the WUR. If i could go back and do it all over again, i would invest in a fuel pressure tester (like Jim Sims indicated) and only replaced the parts that were not functioning to spec. I would have saved a bundle. Since you made it this far, the WUR would be next on your list of things to replace. Pretty soon, you will have a brand new intake system

[78Jason]

wow... thats reassuring. i'm gonna do it!

and you know another thing I'm noticing a lot? Porsche Owners have the same taste for Simpsons! I only watch simpsons each week!

that's great....

By the way - does the system have to be recalibrated in any way after replacing the WUR?

[Kemo]

In my case, the WUR sure did solve alot of issues including a really rough start and idle. Hopefully you will get some improvement by replacing it. However, I would hate for you to replace it and that not be the problem. Hence the pressure tester recommendation

you will have to set your air/fuel mixture and set your idle. be sure and check your timing and make sure your advance is working. some on the board recommend 35 BTDC at 6000 rpms. However, for my car, the standard 5 BTDC at 1K works fine and is less noisy.

if you dont have waynes book, 101 projects, that would be a good investment as well.

as far as the simpsons, i would be a little leary of anyone who doesnt like the simpsons.

Good Luck

[maxnine11]

some good Bosch CIS reading here http://www.auto-solve.com/mech_inj.htm#MFI10 ..max

[Superman]

Truly I say unto you....many many DIY mechanics have spend frustrating, obscene amounts of money trying to fix CIS fuel system problems unsuccessfully. This is very very common. Why do they do this? Because they guess at what might be wrong, instead of going through the troubleshooting procedures. Those procedures essentially BEGIN with a test of cold and warm fuel pressures.

[78Jason]

I know Superman .... then this all really started when I bought it 3 years ago and spent obscene amounts of money on a "top porsche mechanic" recommended to me and he didn't find the problem. So I started doing it myself. At least "obscene" doesn't include fees for someone else now!


Another point- when my idle sticks high - the clutch trick doesn't seem to work now, but if I kill the engine, and restart - the idle is normal - 950. Also - it returns to normal every 10 stops or so.... Does any of that give another clue?

thanks -

[Kemo]

throttle linkage? intake leak maybe? very troublesome.