Running on 2 Cylinders |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
Running on 2 Cylinders |
rickso71 |
Jul 24 2005, 05:21 PM
Post
#1
|
Member Group: Members Posts: 74 Joined: 31-October 04 From: Derry, NH Member No.: 3,041 |
I have a rebuilt (by PO) 1.7L motor in my '71 that was just started for the first time. It has been converted to a single Weber 32/36 carb (I know, not the best setup). It sounded odd, like a Harley but I was just thrilled it ran. When it wouldn't idle I decided to check if all cylinders were running. #2 and #4 aren't running since removing the plug wires made no difference in running. I didn't think to feel for warm exhaust pipes but I'm pretty certain they're not running. THere is spark at #2 and #4 plugs and I'm quite certain I have the wires in correct locations on distributor. I tried moving them around but the only combination that runs is where #1 and #3 are supposed to be. The timing is set at 34 deg. BTDC (as it should be for carb) and when I set the valve clearances, the cylinders all reached TDC on compression stroke when they should relative to where the rotor was pointing .
Was the engine built incorrectly? Are the intake runers for #2 and #4 blocked by the wrong gasket under the carb? Are my ignition wires in the wrong order? What have I missed? |
bd1308 |
Jul 24 2005, 05:35 PM
Post
#2
|
Sir Post-a-lot Group: Members Posts: 8,020 Joined: 24-January 05 From: Louisville,KY Member No.: 3,501 |
1-4-3-2 is the firing order, 1 is top left on the distributor.
fouled plugs? |
rickso71 |
Jul 24 2005, 08:31 PM
Post
#3
|
Member Group: Members Posts: 74 Joined: 31-October 04 From: Derry, NH Member No.: 3,041 |
Yes, 1-4-3-2 firing order. #1 is not top left on my distributor (different for carbs) but bottom right... trust me. Found the problem. The adapter plate between the carb and the intake runners has two holes, one for each barrel and is meant for a plain old dual carb. With the progressive, only the primary is used normally, so that fed #1 and #3. When the secondary kicks in it feeds #2 and #4. I need a different plate, one with a single hole that covers both barrels.
Ran surprisingly well on 2 cylinders but wouldn't hold an idle below 1000RPM. Going to check with Redline on whether I need a new plate or can just modify existing one. |
Allan |
Jul 24 2005, 08:38 PM
Post
#4
|
Teenerless Weenie Group: Members Posts: 8,373 Joined: 5-July 04 From: Western Mesopotamia Member No.: 2,304 Region Association: Southern California |
C'mon guys... Let's help him out. Scott, Joe, Aaron, Alberto, Mike, Howard, etc... C'mon.......
Sorry, I didn't know Britt had already solved the problem.. (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif) |
Mueller |
Jul 24 2005, 09:04 PM
Post
#5
|
||
914 Freak! Group: Members Posts: 17,146 Joined: 4-January 03 From: Antioch, CA Member No.: 87 Region Association: None |
properly setup, the location of #1 on the dizzy should be exactly the same whether it be carb'd or fuel injection if using stock or stock replacement distributors, someone installed something incorrectly on your motor.... normally, when the #1 cylinder is at TDC, the rotor should be facing the driver seat or close to it for the plate, do you need it or can you just modify it?? |
||
newto914s |
Jul 25 2005, 01:44 AM
Post
#6
|
Senior Member Group: Members Posts: 561 Joined: 16-February 04 From: Thornton, CO Member No.: 1,663 |
Could you bring the car up to Redline?
I think I'm running on 3 holes and I can't rev past 5k rpms |
Lo-Fi Version | Time is now: 31st May 2024 - 11:10 PM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |