rough idle after warm up.
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rough idle after warm up.
I just got an '87 F250 with the 460. It was running rough at idle after warmup. I have replaced the plugs, wires, cap, rotor, coil and then had to replace ICM because it quit.
I did not replace the pick-up coil in distributor, but that is the only thing remaining that I know of. I removed the vacuum line and set the timing to 8 DBTDC. I don't have a tach to know what my idle speed is. Supposed to be 800 when timing.
When it is cold it starts good and sounds smooth at idle. It runs pretty smooth at higher RPMS. Once the engine is warm though and I go back to idle is misses and sounds rough.
This should be simple for a pro. Let me hear from that pro please
I did not replace the pick-up coil in distributor, but that is the only thing remaining that I know of. I removed the vacuum line and set the timing to 8 DBTDC. I don't have a tach to know what my idle speed is. Supposed to be 800 when timing.
When it is cold it starts good and sounds smooth at idle. It runs pretty smooth at higher RPMS. Once the engine is warm though and I go back to idle is misses and sounds rough.
This should be simple for a pro. Let me hear from that pro please
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From: Geneva NY
On your engine, there are probably a couple little colored things threaded into the block with vacuum lines hooked up to them. My 351w had a red one and a yellow one. They are "switches" that change what vacuum line gets what dependent on coolant temperature. I believe one of them is tied into distributor advance.
Go to the auto parts store and buy a can of Carb Cleaner (if you run out of starter fluid and need some, an engine will run on carb cleaner fyi). When the engine has warmed up, do your best to not get it in the intake, but start spraying your vacuum lines with short bursts (give it a quick spray then listen, then repeat) If your truck revs up a little then the spot you just sprayed has a vacuum leak.
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From: Virginia
460's are really bad about burning out the gaskets under the carb. The EGR valve does this. There are a couple different setups, some sandwich the EGR under the carb, and you have two gaskets under there. There have also been instances when the EGR has eaten away at the aluminum and won't let the gasket seal.
While you are looking at all the hoses, I would go ahead and pull the carb and anything else up off the manifold and put new gaskets under there.
While you are looking at all the hoses, I would go ahead and pull the carb and anything else up off the manifold and put new gaskets under there.
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Joined: Apr 2013
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From: Geneva NY
460's are really bad about burning out the gaskets under the carb. The EGR valve does this. There are a couple different setups, some sandwich the EGR under the carb, and you have two gaskets under there. There have also been instances when the EGR has eaten away at the aluminum and won't let the gasket seal.
While you are looking at all the hoses, I would go ahead and pull the carb and anything else up off the manifold and put new gaskets under there.
While you are looking at all the hoses, I would go ahead and pull the carb and anything else up off the manifold and put new gaskets under there.
If you do pull the spacer off, make sure to clean all those carbon deposits up.
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Ok guys,
The parts store is a long run for me. What are the chances that the EGR is bad? I guess I could take it in smaller steps and just try gasket and hoses.
Just thought I would check if there is that chance and I may consider replacing the valve while I'm at it.
Thanks for the leads thus far!
The parts store is a long run for me. What are the chances that the EGR is bad? I guess I could take it in smaller steps and just try gasket and hoses.
Just thought I would check if there is that chance and I may consider replacing the valve while I'm at it.
Thanks for the leads thus far!
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From: Virginia
Since your lines are all plugged off and disconnected, the valve is probably not even hooked up. If you have no plans to hook all these lines up, I would not buy a new EGR, I would just block it off at the valve itself.
Don't worry about the gasket, if you need one and don't have it, a homemade one from a cereal box will do till you get one.
Don't worry about the gasket, if you need one and don't have it, a homemade one from a cereal box will do till you get one.
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