 Stumped, motor won't fire on #1 |
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| Rusty |
 Sep 17 2018, 04:25 PM
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#1
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Wanted: Engine case GA003709  Group: Admin Posts: 7,959 Joined: 24-December 02 From: North Alabama Member No.: 6 Region Association: Galt's Gulch 
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We're stumped. I even caved and took it to my local VW expert for help.
Background: The car had been stored for 7-8 years. Before storage, it had been worked on by a third party (including replacing the distrubutor, IIRC). When the car was stored, it was running poorly. Symptom: Car won't fire on cylinder #1, but fires fine on 2 thru 4. (Was it firing on #1 prior to storage... I dunno. I stored it out of frustration.) Motor: 1973 1.7L, dual Weber carbs, Pertronix points replacement in 009 distributor. Details: Car has air, fuel, and spark. Air: Valves are adjusted correctly (.006) and timing is on. Compression on all cylinders is 90-95 pounds. Heat exchanger removed and checked for obstruction. Covering/blocking the air intake on #1 has no effect to the motor running. Fuel: Carb on cylinders 1/2 has been cleaned and adjusted. We can watch fuel go into the cylinder. Some of it ends up as white smoke going out the exhaust. There is an oil leak on the drivers side of the motor and the oil smells faintly of fuel. Spark: Plug wires are routed correctly. Taking a plug out and laying it on engine tin, spark is strong. Wires, cap, rotor, and plugs have all been swapped out. Pulling the plug wire on #1 at any RPM results in no change. I talked to my guy today... he's very well regarded in the area. He's as stumped as I am. Any thoughts? |
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| John |
Sep 18 2018, 12:49 PM
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#2
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member? what's a member? Group: Members Posts: 3,393 Joined: 30-January 04 From: Evansville, IN (SIRPCA) Member No.: 1,615 Region Association: None |
If it's always cyl#1, at least you have narrowed it down some.
If compression is good, it can only be fuel or ignition. If the plug fires when grounded to the tin, it's a good sign, but harder to test once installed in the engine. I test them using the magnetic pick-up of a strobe type timing light or an inductive spark checker along the plug wire (the in-line spark checkers would accomplish the same thing). That insures that the circuit is complete and the plug has a decent ground. If spark is good it really points toward fuel. If it does not spark when the plug is screwed into the head, it may not be grounded well or at all, or could be a bad plug. Test one thing at a time and you will figure it out. |
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Posts in this topic
Rusty Stumped Sep 17 2018, 04:25 PM
nickg check to see if the cap is secure on the distribut... Sep 17 2018, 05:00 PM
Rand
check to see if the cap is secure on the distribu... Sep 17 2018, 05:04 PM rudedude Did you test the plug from that cylinder for spark... Sep 17 2018, 05:15 PM Rand Did you read his post? Not trying to sound krusty,... Sep 17 2018, 05:19 PM Rusty
check to see if the cap is secure on the distribu... Sep 17 2018, 05:26 PM cuddy_k maybe the fuel isn't fully atomizing? Try swit... Sep 17 2018, 05:40 PM Rand I like Ian's thinking. Fuel has to be the high... Sep 17 2018, 05:44 PM worn
I like Ian's thinking. Fuel has to be the hig... Sep 17 2018, 05:51 PM cuddy_k Depending on the linkage, swapping the full carb f... Sep 17 2018, 05:55 PM Chris914n6 intake valve not opening, bent pushrod or somethin... Sep 17 2018, 05:58 PM Rand
intake valve not opening, bent pushrod or somethi... Sep 17 2018, 06:03 PM michael7810 Also check the idle jets and mixture screw port fo... Sep 17 2018, 06:00 PM flyer86d Weber carbs run on the idle circuit about half way... Sep 17 2018, 06:08 PM VaccaRabite Dirty plug? Pull the plug and wire wheel off the ... Sep 17 2018, 07:34 PM Rusty I do appreciate all the replies. I'm taking n... Sep 17 2018, 07:50 PM Spoke Have you checked the airflow into each cylinder us... Sep 18 2018, 08:17 AM struckn I'm know expert but I had a similar condition ... Sep 18 2018, 08:54 AM IronHillRestorations I too suspect a fuel delivery problem for that bar... Sep 18 2018, 11:29 AM wndsrfr
I too suspect a fuel delivery problem for that ba... Sep 18 2018, 12:20 PM 7TPorsh Vacuum leak on the intake top or base? I would tr... Sep 18 2018, 12:02 PM jvmarino Maybe try swapping #1 plug with another cylinder p... Sep 18 2018, 01:06 PM Rusty I picked up the car today and discussed some of th... Sep 18 2018, 04:26 PM cuddy_k
Have you checked the airflow into each cylinder u... Sep 18 2018, 04:49 PM |
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