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| Registered |  Fuel Pump Theoritical Problem 
			Is it possible for the fuel pressure to be so low that there is enough pressure on the left side (closest to the pump) for the cylinders to fire but by the time the pressure gets to the right side there is not enough fuel pressure for the right side cylinders to fire? Thanks.
		 
				__________________ Mike '84 911 Carrera Coupe (totaled) '83 911 SC Coupe ‘06 Aston Martin Vantage V8 | ||
|  04-30-2005, 04:42 PM | 
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| Registered Join Date: May 2001 Location: Peoples Republic of Long Beach, NY 
					Posts: 21,140
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			a non experienced 3.2 guess is a big No..
		 
				__________________ Ronin LB '77 911s 2.7 PMO E 8.5 SSI Monty MSD JPI w x6 | ||
|  04-30-2005, 06:31 PM | 
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| Bland | 
			The pressure would be equal everywhere - think of your fuel lines as a plenum that is pressurized by the pump.
		 
				__________________ 06 Cayenne Turbo S and 11 Cayenne S 77 911S Wide Body GT2 WCMA race car 86 930 Slantnose - featured in Mar-Apr 2016 Classic Porsche Sold: 76 930, 90 C4 Targa, 87 944, 06 Cayenne Turbo, 73 911 ChumpCar endurance racer - featured in May-June & July-Aug 2016 Classic Porsche | ||
|  04-30-2005, 07:44 PM | 
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| Registered Join Date: Jan 2003 Location: Dallas Texas USA 
					Posts: 486
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			Electrically there are only two circuits for all six injectors... The injectors for cylinders 1, 2 and 3 are wired in parallel, and for 4 , 5, 6 are in parallel.  That means injectors 1, 2 and 3 all fire at the same time, and 4, 5 and 6 all fire at the same time. I'd expect some sort of electrical problem if only half the injectors were working. Anything from a bad DME, to a broken wire or connector. 
				__________________ Paul 2001 CLK55 AMG, 1987 911 Turbo Look, 1997 Viper GTS. | ||
|  04-30-2005, 09:12 PM | 
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| Registered | 
			Ok. Thanks. That's what has me puzzled. I have the DME tested and it is OK. I used a noid to test the injectors and they are firing. I used a stehescope to listein to the injectors and they are all clicking. I used a inline spark detector and I am getting spark. Replaced the rotor, cap and plugs just ot make sure. I pulled a plug on the right side and itis dry.
		 
				__________________ Mike '84 911 Carrera Coupe (totaled) '83 911 SC Coupe ‘06 Aston Martin Vantage V8 | ||
|  05-01-2005, 04:56 AM | 
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| Registered Join Date: Feb 2001 Location: Viera FL 
					Posts: 5,642
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			Sounds like the fuel pump relay or the DME relay is shot. ALso check the ground points in the engine compartment. Make sure all electrical connetions are good and tight. AFJuvat 
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|  05-01-2005, 07:04 AM | 
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| Registered Join Date: Dec 2003 Location: Arapahoe County, Colorado, USA 
					Posts: 9,032
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			Mike, Hopefully the problem is something simple in the fuel injection. When one bank of a 911 isn’t working, one thing to check is the functioning of the cams. I would recommend a cranking compression test on all six cylinders. You might go farther and measure the valve clearance and cam timing. You are checking to verify that the 4-5-6 cam hasn’t jumped timing. Best, Grady 
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|  05-01-2005, 07:20 AM | 
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| Registered | 
			Ok. Thanks guys. Since the left side fires fine and actually holds a steady idle, I am focusing on something that could only impact one side. I just replaced the DME relay so I do not believe that is the problem. Although I just had a compression and leak down test last August, I will try another compression test to rule it out.  This all started about 4 months ago after removing the fan and alternator. When I removed the fan shroud I knocked off the dist cap and bent the rotor. I replaced both the cap and rotor. Since I have spark on the right side, I have focused on fuel problems. Now I am wondering if I might have done something to the distributor, which is not giving me spark at the right time. Thoughts? 
				__________________ Mike '84 911 Carrera Coupe (totaled) '83 911 SC Coupe ‘06 Aston Martin Vantage V8 | ||
|  05-01-2005, 11:56 AM | 
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| Registered Join Date: May 2001 Location: Peoples Republic of Long Beach, NY 
					Posts: 21,140
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				__________________ Ronin LB '77 911s 2.7 PMO E 8.5 SSI Monty MSD JPI w x6 | ||
|  05-01-2005, 01:15 PM | 
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| Registered | 
			I checked the compression in cylinder #4. It is 179 Lbs. Last August when I last had it tested it was 175 Lbs.  Lack of compression does not seem to be a problem.  I had another thought, even though the injectors are firing, could the injectors still be clogged so that fuel is not getting through?
		 
				__________________ Mike '84 911 Carrera Coupe (totaled) '83 911 SC Coupe ‘06 Aston Martin Vantage V8 | ||
|  05-01-2005, 01:51 PM | 
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| Registered | 
			OK. I feel pretty stupid, but I found the problem. Of all things it was the spark plug wires not seated properly. It's running like a champ now. Can't believe it only took me 4 months to figure it out! I almost forgot how much fun it was to drive this thing! Thanks for all your help.
		 
				__________________ Mike '84 911 Carrera Coupe (totaled) '83 911 SC Coupe ‘06 Aston Martin Vantage V8 | ||
|  05-01-2005, 03:14 PM | 
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