Jay Laifman

Ok, I may come back and recant all of this, especially since I've been a very long supporter of my 73.5 CIS, and tend to try to encourage people to not dump CIS for carbs. But, I'm in the middle of train wreck and I'm going to tell about it.

My 73.5 has been through three rebuilds and countless CIS changes for the last 4 years, and now the latest problem appears to be that the fuel distributor is bad. But, when we were trying to track down the source of my poor running, I personally brought it to Python who rebuilds fuel distrubutors to test it. They tested it and gave me this nice form showing it passed with flying colors. So, we IGNORED the FD during tracking all the problems, which lead to the third rebuild. Yet now it seems like it really is bad. This of course brings in to question Python's testing abilities - and of course since this is the test they run all their rebuilds through, this brings into question their rebuilds themselves!

So, of course, what to do? Break down and buy a rebuilt one from Bosch. But, guess what? No one has them! Not even Pelican. Had I known that after all the money I have spent on new CIS pistons and rebuilding the heads twice, that I'd end up with a part that is NLA, I'd have gone in such a different direction! A rip roaring 3.0, hot cams, hot pistons, hot PMOs and be done with it! But, NO! I had to love how my 73.5 CIS runs (or ran) and do tend towards originality.

My mechanic has a guy in Alabama who apparently can rebuild the fuel distributor, and do a good job.


As an aside, the original rebuild was to fix worn valve guides, which included a new clutch and P&Cs with Deves rings. The second rebuild by the same guy with help from another Porsche mechanic was because it wasn't running well, the new rings were not sealing, and it had a vibration at 2,300 rpm. The Deves rings were replaced by OEM and it was rebalanced. But, still it did not run right and the 2,300 rpm vibration was still there. I decided to take more into my own hands, and with the help of Pete Z. and Jim Williams, and Art Z, found that the WUR was dead, the cold start o-ring was the wrong one, the throttle body had been epoxied to the airbox, the fuel pressure was too high, the intake runner gaskets had been reused multiple times, and the airflow plate was not adjusted exactly right! I fixed all that, for a noticable but partial improvement. Thus, a third rebuild, now by a completely new mechanic. This third mechanic found that the clutch was bent, probably by a bad installation during the original rebuild and the head rebuild was a disaster: the exhaust valves were burnt and had not been replaced, the valve seat grinds were bad, and the valve guides were too long causing the valves to bottom out on the guides not the seats! So, the 2,300 rpm vibration has been fixed with the new clutch and the valves are much happier now. But, still not perfect, and thus back to the fuel distributor. Anyone want to trade an almost perfect 2.4 CIS engine for anything else?

Brett San Diego

Jay, so sorry to hear of your tribulations. This is why I'm convinced I must do all the work on my cars myself. I can't trust anyone to do the job correctly.

I presume you've read the fuel distributor rebuild threads on the Pelican forum. Some people seem to have had success on their own. Maybe you can get away with just a good cleaning of the fuel distributor piston and cylinder (without complete disassembly, if that's possible) and replacement of the piston seals and then a good cleaning (refurbishment) of the sensor plate and fulcrum mechanism.

If I had your 911, I'd want to keep it original, too. Love the original color scheme. Save the hot-rodding for when you're bringing back an already lost cause for originality.

Brett

Stevie 77 930

Wow, with many decent shops in the San Fernando Valley, I am surprised that you havent seemed to find a mechanic who can nail down your issues. With that said, check this guy out for a Fuel Dist rebuild.
http://www.specialtauto.com/porsche-parts/index.html This guy did both my FD and WUR and so far so good for me.

gecc

If it's Larry at CSI Flow tec he does a great job. He also rebuilds w/r regulators.

ATSAaron

That is the same people that do Venom performance fuel injectors. They have a horrible reputation in the MR2 world. Sorry it happened to you.

Aaron

Jay Laifman

Actually, I have it up in Santa Barbara at a shop I can't say enough about. Yes, they have gone through hell and back trying to figure it out. But, that's just the nature of the beast. Even though it now appears to have been that last thing after a terribly long list, isn't that the way it always is? They also could have just given up and said that it was a problem caused by another mechanic and they don't want to get involved with that headache. But, they didn't. They just kept going and doing the right thing. And, also, had they not had the abilities they have, they may not have ultimately actually figured out that the fuel distributor was actually the wrong one on the car! Perhaps they were clued into it being the wrong FD by the guy who rebuilt it. But, still, they still get credit for knowing the right guy to send it to rebuild in the first place.

They have a correct FD now being rebuilt soon to be sent back. I've scheduled a date in two weeks for them to install it. I have a lot of reserved optimism that it's finally going to be that car again when the mechanic says "this is a great, no excuses, 911 to drive." Just like the "first 10 that Porsche built" that Peter Z. labeled it in his book!