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Registered
Join Date: Jan 2007
Posts: 472
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backfiring and starting issue????
I have a 1982 porsche sc, sometimes when the car is cold it has trouble starting up but when its starts up it runs like a champ, and when its warm the car starts up perfectly everytime. However i noticed when the car is off (but warm) but the radio is on, sometimes it will have an issue starting, is it because the fuel pump is running and its drowning itself in fuel? fuel pump issues? starter??
Also my car is starting to backfire a lot lately, maybe once or twice every minute? doesnt effect performance, just wondering if i can fix it or not.... |
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02-15-2008, 08:25 AM
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Registered
Join Date: Feb 2008
Posts: 222
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There are probably a number of other reasons, but any time I've had backfiring issues - with several 911's - including my 83SC Coupe - , it's always pointed back to a failing, or failed, fuel pump.
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02-15-2008, 08:32 AM
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Designer King
Join Date: Mar 2004
Location: Toronto, ON Canada
Posts: 5,499
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Cold start issues are very often the fault of an out of spec Warm Up Regulator which provides a too high control pressure, resulting in a too lean condition. A search will reveal a lot of talk about this.
You might want to look into your fuel accumulator and fuel pump check valve. Also, often the battery may be not quite up to scratch, which is why the car may have trouble starting while there is added draw (eg the radio). When does this new backfiring occur? Warm? Cold? Idling?
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Paul Yellow 77 Sunroof Coupe/cork interior; 3.2L SS '80 engine/10.3:1/No O2; Carrera Tensioners; 11 Blade Fan; Turbo tie rods; Bilstein B6; 28 tube Cooler; SSI, Dansk; MSD/Blaster; 16x7" Fuchs/205/50 Firestone Firehawk Indy 500s; PCA/UCR, MID9 Never leave well enough alone |
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02-15-2008, 12:04 PM
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Registered
Join Date: Jan 2007
Posts: 472
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backfiring occurs when it is warm
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02-15-2008, 02:51 PM
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Designer King
Join Date: Mar 2004
Location: Toronto, ON Canada
Posts: 5,499
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Aside from what I mentioned above, I would check for vacuum leaks, including all vacuum lines and connections to the AAR, AAV, WUR, decel valve etc. I would also check the airbox and popoff valve.
Since backfiring and poor starts are often mixture related I would check my mixture, or try at least temporarilly richening it and seeing what happens. On the ignition side I would check plugs, rotor, cap and wires.
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Paul Yellow 77 Sunroof Coupe/cork interior; 3.2L SS '80 engine/10.3:1/No O2; Carrera Tensioners; 11 Blade Fan; Turbo tie rods; Bilstein B6; 28 tube Cooler; SSI, Dansk; MSD/Blaster; 16x7" Fuchs/205/50 Firestone Firehawk Indy 500s; PCA/UCR, MID9 Never leave well enough alone |
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02-16-2008, 08:01 AM
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