Guy

Thanks for posting! I am strongly leaning in that direction. Thinking of either getting my unit rebuilt again or at least having it benchtested professionally to confirm my findings so far. Frankly, I don't mind dropping the money, just ready to move onto to other things

SMTCapeCod

From what I recall, factory rebuilt FD sometimes have the adjustment screws added. I don't think factory ones do.
Does sound like FD is the problem.
I've had some that have fine plastic-ish screens in the port for each fuel line, and some that don't. Might do to check for clogs/occlusion and presence/absence to see if they are all the same under the banjo bolt that fastens the line to the FD.
Pictured here by the orange o-ring
http://i59.tinypic.com/ay3hgw.png
I'm not 100% up on who is doing good jobs on the FDs now. There was a Delorean place that seemed to have a decent reputation. Maybe/hopefully some Porsche talent available now as well, though they are essentially the same Bosch engineering.

Guy

Thanks for the information. My screens are long gone but I really wish I had replacements. I was very nervous about reinstalling everything after all the plating work that was done. I feared a small piece of metal swarf getting lodged somewhere and perhaps that's exactly what has happened.

Last night I pulled everything. The FD, WUR, and all the injectors (God, I hate the brass injectors). Jim at 928Classics graciously accepted them for some testing etc. We are going to get this fixed finally, I think this is the final piece of the puzzle. I am anxious to enjoy this car!

Take a look at this picture. This is just after I pulled the fuel distributor. I kept it level so as not to spill any gas on my garage floor. Take a look down the ports.



All the ports have fuel except #1. This was two days after the car ran last. Totally unscientific but just too much of a coincidence.

Thanks for all the help!!

SeanR

Jim has built a nifty test rig for this, he should be able to fix you up.

GlenL

My understanding is that the factory units did not have the adjusters but units from Mercedes V8s did.

Odd but true: I've got three FDs that came on CIS 928s and all have the same part number tag on them and one has the adjusters. The special one came with an '80 Euro S but my other '80 Euro S has the plain FD. What? We'll never know.

Guy

Over the years, I had a few opportunities to pick up spares of the WUR,FD etc. Unfortunately, I really didn't move on them quick enough. I have spares of everything except the CIS stuff. Imagine how nervous I am handing my box over to FedEx today

I have seen the Mercedes units. They used to be reasonable to pick up used. I always resisted thinking that the last thing I need is another adjustment to mess with !

Guy

I am confident he will. Besides my rebuilt original rack, this is the first time the car had any intervention from anyone but me.

Hey, maybe that's the REAL problem all along

kiwiokie

Looks like you have found the smoking gun! Sorry my memory failed me on the adjustment screw comment. I checked my FD and the Bentley book and there is no balancing adjustment. The fuel metering is determined by fine slits in the plunger, one for each injector, and the differential pressure valve for each injector. You could remove and clean the plunger to see if the slit on #1 is clogged with some crud.

Guy

We have an update on my misfire issue. I sent Jim my WUR, FD and a set of original injectors along with 8 new brass injectors that I have been running for the past 1000 miles.

The verdict: all 8 of the brass injectors were bad. They were streaming and not atomizing well. Jim reconditioned my original injectors.

I was not running a FD screen at the inlet and it's possible I contaminated these new injectors early on in the project. I will be adding a replacement inlet screen.

Jim also found the FD was a little unequal in its fuel delivery. That was corrected during bench top flushing.

My parts are due to me tomorrow. I also have a new BOSCH fuel pump to replace my Chinese pump. Hopefully going to get it all installed tomorrow and will report back.

BIG thanks to Jim Doerr to taking on the parts and getting me sorted out!

skpyle

Excellent!
Good Luck!

kiwiokie

Guy were you using the shorter Mercedes injectors?

Guy

Yes. Really don't care much for the brass injectors. They are very difficult to remove in the 928 application as the soft metal deforms easily on removal. Jim reconditioned my original set and I am happy to have them back!

Got my Bosch fuel pump installed and I can tell you that while they look identical to the Chinese junk, it is so much quieter! It also has an internal check valve which actually works. The Chinese ones don't have a working valve on the cis pumps. I was surprised that the Bosch pump didn't include the nuts for the contacts where as the counterfeit did.

Installed the FD, WUR AND injectors last night as well. After priming to check for leaks, car started right up and idled very nicely. Sounded good, felt good. Unfortunately, it was raining bad so I couldn't test drive. For those keeping score, I have been here before so whether the car remains consistent is going to be the real test. I am cautiously optimistic!

If it drys up, will be getting it out tomorrow

GlenL

This is surprising. Were those real Bosch units and any thoughts on if they got contaminated or something?

I run these and the results have been generally good.

Guy

I don't believe they were genuine Bosch. In addition, my gauge set may have introduced contaminant many moons ago early in this project.

I learned a hard lesson back then. Used the gauge set when I first got the car prior to a complete flushing. After the flush, I used the gauge set a fee times and couldn't understand why I kept getting my WUR screen clogged. Duh! Again, this was a couple years back. Older and wiser

crushingday

Damn weather! I am anxious to hear how it drives.