Sloppy idle in drive

[Anonymous]

How do I adjust the idle while in drive? The engine runs smooth in park or neutral but gets a little rough in gear. I currently have a Carter YF rebuild.


-Chris

 

[Anonymous]

If you have a stock cam, the books call for 550-625 RPM in gear. Use 650 RPM in gear with air conditioning. The 550 RPM becomes almost 700 RPM in neutral, while the 650 becomes almost 800.

If the intake valves are dirty (very common on these engines, especially in cylinders #3 & #4), it will idle roughly. Try running a can or 2 of BG44 through the gas, one can per tank. It's not cheap, but it does an excellent job without damaging the carb (which gas cleaners like Gumout often do). This will clean those valves and restore a noticeable performance improvement (unless the engine is already brand new).

 

[Anonymous]

Sounds like the timing..

 

[Anonymous]

Thanks guys.

I'm afraid is could be the timing - still. But it does run smoother than the first couple of hours of operation. So far I've logged about 12 hours since the rebuild (which included new valves but original cam). So timing could still be a bit of my problem.

However, the gas tank is original as well as the fuel line from the tank to the pump. It might be a good idea to flush the fuel delivary system as well as clean the carb - again.

Oh, one more thing. The engine smoothes out after depressing the accelerator. Just a little rough when put into gear and sitting at a stop.

So, I'll try the BG44 and adjust the timing some more. Oh - better check the vacuum line for the transmission as well. Forgot about that part.


-Chris

 

[Anonymous]

if it runs smooth in park or neutral then its most likely a timing/idle speed screw setup not quite right....put the e brake on then put the car in gear, then tighten the idle speed screw till its about 7-800 rpm, then if it still runs crappy, loosen the horseshoe that holds down the dist and advance or retard untill u get it running smooth, once it runs smooth u can adjust the idle speed screw to whatever u want, i dont have a tach but if i compare the sound to my friends car i'd say i idle at about 800-900 rpm, which is a little high for idle but when your in gear its actually quite nice. i find using stock idle speed causes the car to take too long to get from 0-? but using a faster idle uses up more gas at idle (i dont need to warm up the car, i just turn it on and go) it gets to speed quiker....but yea if this doesnt help then it could be either the cam or another part of the valvetrain. (since u said it runs good at idle then im pretty sure its the timing/idle screw) my car runs a bit rougher in park but when i put it in drive it sound smooth and sweet.