5.0 idles problems
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5.0 idles problems
I recently bought a 1981 f150 custom, with a 5.0 out of a mustang. It does have a carburetor but am not sure year of stang the motor was pulled out of. The problem is it just won’t idle. I replaced the electric choke (got whole housing the fast idle cam and all came with). Got it on the truck pre instructions, it now ‘fast idles’ to warm up but when it kicks down to curb idle it’ll die. Doesn’t try to keep going, if I hit the gas it’ll jump back up as long as I hold the gas, let go and it’ll die. I’m lost as what it could be so any help would be appreciated. It’s my daily driver so need to fix ASAP.
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update: Got the truck to idle, it's high around 3,000 at fast idle. It'll idle good till it hits the last notch on the fast idle cam, then it dies. Thinking its a vacuum leak in the line for the brake booster that's stopping it.
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Kind of, it helped when in park or neutral but in gear it will still stall out. Is this because not enough vacuum, or do you think something else?
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to fix it. It's at the shop at this point.
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In for results, I'll go adjust my mixture screw like ctubutis suggested. Good luck, rblount, I hope we can get this figured out.
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Just because I don't want to start a new post with the same problem, I'm going to continue this post.
I went out and adjusted the idle screw on the carb, like ctubutis suggested, and it does start easily and idle on it's own now. However, it still dies when shifting into gear. It seems like when the rest of the drive train gets engaged it slows the engine down enough that it dies. If I give it a little throttle as I shift, I can save it right from brink of dying. But I have to be pretty careful or it'll just die. Also, I have noticed that there's nothing I can do to keep it from dying when I shift while in a gear to another gear (i.e. reverse to drive).
It's like the fuel cuts out completely for the short amount of time that the shift takes place and it dies before the fuel re-initiates. Possibly the fuel bowl isn't holding fuel, or the fuel filter is clogged, or possibly the timing has been way off the whole time and is affecting it...
What other ideas do people have?
I went out and adjusted the idle screw on the carb, like ctubutis suggested, and it does start easily and idle on it's own now. However, it still dies when shifting into gear. It seems like when the rest of the drive train gets engaged it slows the engine down enough that it dies. If I give it a little throttle as I shift, I can save it right from brink of dying. But I have to be pretty careful or it'll just die. Also, I have noticed that there's nothing I can do to keep it from dying when I shift while in a gear to another gear (i.e. reverse to drive).
It's like the fuel cuts out completely for the short amount of time that the shift takes place and it dies before the fuel re-initiates. Possibly the fuel bowl isn't holding fuel, or the fuel filter is clogged, or possibly the timing has been way off the whole time and is affecting it...
What other ideas do people have?
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When an engine stops running because of a lack of fuel, it's not an instant-off kind of situation; rather, it wheezes and gasps for a bit (and uses up the fuel still in the intake runners) before dying of starvation.
But I would check all the basics, including ignition timing, fuel pressure, spark plug condition, etc.
But I would check all the basics, including ignition timing, fuel pressure, spark plug condition, etc.
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When an engine stops running because of a lack of fuel, it's not an instant-off kind of situation; rather, it wheezes and gasps for a bit (and uses up the fuel still in the intake runners) before dying of starvation.
But I would check all the basics, including ignition timing, fuel pressure, spark plug condition, etc.
But I would check all the basics, including ignition timing, fuel pressure, spark plug condition, etc.
I'll check the spark plugs, plug wires, and dizzy to be sure they are in good condition. I'll have to look up how to check fuel pressure, and I have a timing light, but I've never had to use it!
Hopefully all of this turns out to be something simple!
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The engine doesn't use hardly any fuel at idle. If you want to try an experiment, take the vacuum line off the distributor while it's idling. Does it die or try to die when you do this? If it does, something is not right with this line, it may be hooked to the wrong place on the carb. Leave it off, put a screw in the line to block the vacuum leak, and then tune it and set the idle with it disconnected, and then take it for a drive.