rough idle

[Anonymous]

Hello, I have been wondering why my car all of a sudden started with this problem, well actually the day after. I had set up the timing, which I also wonder if it is normal for the speed to increase once I time it with the vacuum advance off and plugged, set it to TDC, then plug the advance back on, accelerate and it will jump to the middle and a few times it will jump to the very top, what could cause this? Well anyways, I took the car for a spin and it reacted very well. The next day it was colder so I had to use the choke, and the car felt different once it turned on, it was idling rougher, I thought maybe it was cold so I let it warm up a little longer, went for a spin and the car felt the same. I'm not sure what happened!! I replaced the manifold prior to the first run but now the car runs shaky with the choke all the way in. I have timed it, I cleaned the spark plugs which were sooty, played around with the idle and the carb but it still does it. If anyone can tell me anything to solve this I'll greatly appreciate it. Thank you.

 

[Anonymous]

That is normal for the timing to jump or advance when you blip the throttle with the vacuum advance connected or plugged in as you said. Without a load or just a light load, the vacuum does not drop to zero when you blip the throttle, so you get some part of the vacuum advance timing contribution. Also when you blip the throttle, the centrifugal advance (if equipped on your distributor) will kick in as the engine speed increases.

The rough idle and plug description sounds like you have a rich condition. If you cannot correct it by trimming back the idle fuel mixture screw, then you might have a choke plate that is not fully open or a float level that is too high. Another possibility could be valve stems leaking oil and fouling out your plugs quickly.
Doug

 

[LEROY POLL]

HEY THERE EDU....? ( WHAT'S YOUR NAME?)


.....AS I READ YOUR POST....YOU SAID YOU TIMED THE MOTOR TO TDC. I WONDERED IF THAT WAS A SLIP OR YOU DID SET IT TO TDC. IT WILL DEPEND ON YOUR MOTOR ...BUT MOST WILL BE SET UP TO 6* OR 12* WITH A VERIBLE OF 5* HIGHER.

.....TELL US YOUR NAME AND WHAT CAR, MOTOR AND YEAR AND TRANNY YOU HAVE. THAT WILL HELP.

LIVE IN GRACE

LEROY POLL

 

[Anonymous]

Hi Leroy, my name is Edouard but my friends call me Edu. I have a '62 Falcon, 170cid, fordomatic. I have checked the idle screw and it helps somewhat but I have to screw it in all the way. I also checked the choke plate, is it the top one that is attached to the choke cable? If it is, it is opened all the way. As for the float, I had the carb rebuilt a while back and it ran well, I had previously driven the car and it was ok, then I changed the manifold because the old one was leaking. I rechecked everything, and it ran very smooth. Even when I took it home it was fine. Then the next night when I had to use the choke because of the weather that was when I noticed it was running rougher. It also shakes very little then rough and again just like a pattern. I hope this gives more info on what happened so you guys can help me get back to running smooth. All appreciated, thanks.

 

[LEROY POLL]

HELLO EDOUARD


.....SORRY ABOUT THE NAME. EDU IS OKAY.

.....IT SOUNDS LIKE YOU HAVE HAD THE CHOKE CHANGE ON YOU. RECHECK THE CHOKE AND WATCH AS SOMEONE PULLS IT OPEN. THEN MAKE SURE THAT WHEN THEY PUSH IT BACK IN THAT IT CLOSES ALL THE WAY.

.....I BELIEVE YOU ALSO MUST HAVE A PROBLEM WITH THE IDLE CURCUIT IN THE CARB. TO TURN THE IDLE SCREW ALL THE WAY IN YOU ARE SHUTTING DOWN THAT SECTION OF THE CARB. YOU MOTOR SHOULD NOT IDLE AT ALL THIS WAY. SO YOU HAVE A LEAK OR THE LINKAGE IS OPEN TOO MUCH. TRY TIGHTING THE CARB. DOWN TO MAKE SURE YOU DON'T HAVE A LEAK THERE. AFTER THAT DO THIS.

.....START BY LEAVING THE CHOKE OPEN. NOW TURN THE IDLE SCREW ON THE BASE OF THE CARB. OUT 2 1/2 TURNS AND THE LINKAGE SCREW BACK OFF INTIL IT IS NOT TOUCHING. NOW TRY TO START THE MOTOR. IF IT WOUN'T START THEN TURN THE LINKAGE SCREW IN 3/4'S OF A TURN, AND TRY AGAIN TO START IT UP. ADD 1/2 A TURN ON THE LINKAGE EACH TIME IT WON'T START, UNTIL IT WILL START. IF THIS DOSEN'T WORK THEN COME BACK AND TELL US WHAT'S HAPPENING.

LIVE IN GRACE

LEROY POLL