Rough Idle..
poor idle
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poor idle
All of a suddden last night idle goes in the toilet. Now it barely idles. When accelerator is depressed it seems to come to life. Exhaust has a funny almost missing sound to it too. Checked a few plugs in dark and they seemed ok. Changed cap and rotor - no change. Pulled fuel filter and seemed ok. (that would seem to be more of a problem under load not idle but I was trying to check easy stuff last night)
mine is a 79 F150 4x4 with 351m, holley carb and mainfold with headers and 4spd.
Like I said everything seemed very strong and ran like a clock.
Any suggestions on where to look? I haven't driven Fords for a long time and then recently sold a chevy and bought this ford which is in great shape.
mine is a 79 F150 4x4 with 351m, holley carb and mainfold with headers and 4spd.
Like I said everything seemed very strong and ran like a clock.
Any suggestions on where to look? I haven't driven Fords for a long time and then recently sold a chevy and bought this ford which is in great shape.
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thanks for welcome.
Truck was not used a lot over last couple of years but very well maintained with newer motor, carb, etc. I bought a month ago and have put 300 miles +/- on it.
Couple of other symptons that I assume are unrelated are tough warm starts (crank some and then it catches and fires, acts flooded)
and starter does not catch all the time, it spins but does not engage, usually try it a few times and it catches.
Couple of other symptons that I assume are unrelated are tough warm starts (crank some and then it catches and fires, acts flooded)
and starter does not catch all the time, it spins but does not engage, usually try it a few times and it catches.
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dist.
I have a stock vauum advance type distributor. I am not familiar with ported vacuum on carb. How can I check and fix? Could it be caused by vacuum leak? I have had this on other cars and you can really hear large leak. Would this be something that happened instantly? My situation seems like it ocurred all at once.
What is the black cap I have over a fuel inlet looking line on the passenger side of carb? The tube looks just like a fuel line nipple right above where fuel line goes into carb. but is covered by rotting rubber cap (still looks solid on inside of cap).
thanks for bouncing all this stuff off of me. I learn something new every day. Keep advise coming I have cofidence I will get to root of problem.
What is the black cap I have over a fuel inlet looking line on the passenger side of carb? The tube looks just like a fuel line nipple right above where fuel line goes into carb. but is covered by rotting rubber cap (still looks solid on inside of cap).
thanks for bouncing all this stuff off of me. I learn something new every day. Keep advise coming I have cofidence I will get to root of problem.
Mountain Pass
Joined: Dec 2004
Posts: 123
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From: Maryland
cheyenne-
if it just happened overnight, it's most likely a vacuum leak or a plug. on a 79, especially if it's stock, you may really have to look for the leaking hose, since there are so many. they tend to get soft with age and come off their fittings easily. you mentioned you checked a few plugs...i'd check them all. after all, they don't cost much. also, check the plug wires. you can take them off with the engine running and hold them close to the valve cover, checking for an arc. careful not to zap yourself, though...it hurts. hope that helps.
if it just happened overnight, it's most likely a vacuum leak or a plug. on a 79, especially if it's stock, you may really have to look for the leaking hose, since there are so many. they tend to get soft with age and come off their fittings easily. you mentioned you checked a few plugs...i'd check them all. after all, they don't cost much. also, check the plug wires. you can take them off with the engine running and hold them close to the valve cover, checking for an arc. careful not to zap yourself, though...it hurts. hope that helps.
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Joined: Dec 2001
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From: Louisville,Ky.
It could have gotten a small piece of debris in a port inside the metering block of the carb. Also, did you check the distributor to make sure that it didn't move from not being tight?
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From: lino lakes, mn
vacum leak or possibly a struck EGR may cause the sudden lack of low speed performance the starter not engaging sounds like a bad starter drive you can fix that or c/o the starter the drive is about 10 bucks. The hard starting hot may be advanced timing or a float set a little hi so gas spills over when it is stopped sorta perculates in the carb or a weak autochoke stat spring
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How do I check carb for blockage on metering port?
Checked carb, its not a holley, it is 4 barrel with no name visible. Sits ontop of an edelbrock performer 400 manifold. I assume after market repo. carb looks new
I can't remember method to check plug wires for internal damage or excess resistance. I assume ohm meter and some ohms resistance.
Its my driver and I need to get it back on the road
I'm a little behind learning curve on specifics. What and where is EGR? (is it exhast gas recurculator and if so what does it look like?)
thanks for help sofar.
Checked carb, its not a holley, it is 4 barrel with no name visible. Sits ontop of an edelbrock performer 400 manifold. I assume after market repo. carb looks new
I can't remember method to check plug wires for internal damage or excess resistance. I assume ohm meter and some ohms resistance.
Its my driver and I need to get it back on the road
I'm a little behind learning curve on specifics. What and where is EGR? (is it exhast gas recurculator and if so what does it look like?)
thanks for help sofar.