Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 911 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered
 
Join Date: Mar 2009
Posts: 1,782
early turbo help needed!

My friend Eric has a 77 turbo engine that originally came with a crankfire ignition. We tossed the crankfire and installed a 123 distributor. At the same time we had Timmy2 make an engine harness similar to a 78 harness so that Eric's engine could run with a 6 pin CDI. The engine ran well for a time, but now it barely runs and fills the shop with fumes. I suspect a fuel system problem, but Eric wants to get rid of the 123. Early turbo dizzys are unobtanium, so I am wondering if we could run the engine with a 911 dizzy from a 76 or 77 just long enough to see if that improves things. A couple of questions:
1. Will we do any damage to the engine if it is run at idle through warmup to see if there is any improvement?
2. Can we take a 911 dizzy and have it rebuilt or recurved to an early turbo configuration?
3. Any other suggestions?

Thanks in advance for your help

Old 07-28-2025, 08:02 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered
 
Join Date: May 2023
Location: Longmont Colorado
Posts: 492
Garage
why get rid of the 123 distributor . . if its set up right it is as good or better than factory. Fix your problem . .don't replace random parts until you get to the right solution.
Old 07-28-2025, 08:55 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
PCA Member since 1988
 
Join Date: Feb 2018
Location: SW Washington State
Posts: 4,311
Garage
Not enough problem description. Why do you think it is related to fuel system, and Eric thinks it's ignition?

Yes, you can run the engine on a different dizzy. Just don't run it hard enough to get into boost. If you can swap the CDI box, and coil, try that first.
__________________
1973.5 911T with RoW 1980 SC CIS stroked to 3.2, 10:1 Mahle Sport p/c's, TBC exhaust ports, M1 cams, SSI's. RSR bushings & adj spring plates, Koni Sports, 21/26mm T-bars, stock swaybars, 16x7 Fuchs w Michelin Pilot Sport A/S 3+, 205/55-16 at all 4 corners.

Cars are for driving. If you want art, get something you can hang on the wall!
Old 07-28-2025, 11:12 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Crotchety Old Bastard
 
RarlyL8's Avatar
 
Join Date: Jan 2000
Location: Huntsville, AL
Posts: 15,012
Garage
Early and Euro 930 ignition distributors do not retard on boost; it should be safe to use a 911 distributor as long as the timing is set at 26° @4000rpm. As previously stated I would get the 123 setup working properly or fix the fuel issue, whichever is the culprit.
__________________
RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds
'78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar
Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8
Old 07-29-2025, 05:50 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered
 
Join Date: Mar 2009
Posts: 1,782
Thanks for the discussion. The owner is a very good friend and I don't want him to waste his money by throwing parts at the problem. But he is predisposed to blame the 123. We can borrow a bunch of different model year distributors just to try them and see if any of them make the engine run properly. If I am there, I would look at the pulses on a timing light for each plug and sniff the exhaust with an air fuel meter and compare that with the behavior of the engine running on the 123. I won't be there until November, so all I can do is offer advice via email
So all I need right now is discussion and advice on swapping the distributor.
Thanks in advance
Old 07-29-2025, 02:31 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered
 
Join Date: Mar 2009
Posts: 1,782
Thanks for the discussion. I agree that throwing parts at a problem like this one is a huge waste of money. I am not the owner. The owner, who is a great friend, is inclined to blame the 123. He can borrow several different model year dizzys. So I have suggested that he swap in one or two of them and see if the engine runs better. If not, then we can devise a more thoughtful work plan. At this point, I am just offering advice remotely-I won't be at this shop location until later this year.
Again-thanks in advance for any suggestions.
Old 07-29-2025, 03:32 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered
 
Join Date: May 2023
Location: Longmont Colorado
Posts: 492
Garage
If he is blaming the 123 it is only because he doesn't understand it. You can pull up the current 123 settings on your phone and see if they are where they need to be . . surely if he has one he knows how they are set up . . if not he needs to educate himself . .it is unlikely to be his problem.
Old 07-29-2025, 03:58 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
PCA Member since 1988
 
Join Date: Feb 2018
Location: SW Washington State
Posts: 4,311
Garage
Important: With the 123 in the engine, disconnect the vacuum hose, put a timing light on the engine and run it through the RPM range. The timing marks should move smoothly and remain steady at any particular RPM. Then reconnect the vacuum hose and check again. If the timing moves smoothly and remains steady, then I would look elsewhere.

__________________
1973.5 911T with RoW 1980 SC CIS stroked to 3.2, 10:1 Mahle Sport p/c's, TBC exhaust ports, M1 cams, SSI's. RSR bushings & adj spring plates, Koni Sports, 21/26mm T-bars, stock swaybars, 16x7 Fuchs w Michelin Pilot Sport A/S 3+, 205/55-16 at all 4 corners.

Cars are for driving. If you want art, get something you can hang on the wall!
Old 07-29-2025, 04:43 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Reply


 


All times are GMT -8. The time now is 02:11 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.