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Registered
Join Date: Feb 2001
Location: Jamul, Ca
Posts: 251
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Car went KABOOM
My 74 had been sitting for a couple of weeks due to my mechanical ineptness and when I started it this morning it made a large backfire. It has never done this before. I jumped out after it started and eyeballed the intake box, wiggled it around checked OK. Checked exhaust pipe to see if wife had stuck potato in it, checked OK. What might have caused this and should I check anything else?
------------------ Dan S. 1974 911 Targa |
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06-08-2001, 01:47 PM
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Registered
Join Date: Dec 1999
Location: Los Angeles
Posts: 2,479
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Fuel accumulation somehow....maybe in the muffler or exhaust port?
When I had my 914 mistimed(unbeknownst to me of course) and kept cranking it, and when it finally did start, it blew the muffler in half so there's no limit to what some accumulated gas and a spark can do on startup! (long and the short of this answer is, I have no f'ing idea, but it's almost time to head home....) ------------------ Kurt B (smashed)1984 Carrera Cabriolet 911 Page carrera_cabriolet@yahoo.com |
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06-08-2001, 03:02 PM
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Registered
Join Date: Feb 2001
Location: Jamul, Ca
Posts: 251
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I wonder if it was because I had the gas slightly depressed when I turned the key. Also I usually let the fuel pump run for about a second or so before I turn the key. Is this bad technique?
------------------ Dan S. 1974 911 Targa |
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06-08-2001, 03:05 PM
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Registered
Join Date: Dec 1999
Location: Los Angeles
Posts: 2,479
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No I don't think so. If you think your timing could be the problem, then you could use the 914 as a starting point. I guess, if your distributor broke or something and put your timing off 180 degrees or so, explosions like that are possible. Mostly for those cars, the airbox explodes...but if you've a pop-off valve that shouldn't happen. Someone else will hopefully chime in here with some experience with this specific case!
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06-08-2001, 03:59 PM
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Registered
Join Date: Mar 2001
Location: Marysville Wa.
Posts: 22,466
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it just happens sometimes. are any of the screws out a bit? if so the airbox seam has seperated. a flame gets past the intake valve due to carbon between the valve and seat and lights off the cold start valve spray. get a pop off valve. early cars needed some throttle opening to close the microswitch to activate the cold start valve.
[This message has been edited by john walker's workshop (edited 06-08-2001).] |
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06-08-2001, 05:13 PM
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