verdelizard
Member
- Joined
- Jul 8, 2010
- Messages
- 15
- Reaction score
- 0
- Location
- Texas
- My Car
- 1971 Mach 1 Mustang
351 Cleveland
I have a 1971 MACH 1 with a 351 Cleveland 2 barrel carb. Recently it started idling EXTREMELY roughly while in gear. It idles fine when it is in park or neutral, but not in any gear. I removed the distributor cap while investigating, sanded the points and cap/rotor contacts, and lost all but the most intermittent spark (verified with a timing light). I put on a new distributor cap, rotor, points, and condenser. The car then exhibited the same condition, idling in neutral but not in any gear. I have since changed the plugs (all of which looked really good except number 3, which looked wet) and the wires. The same condition exists.
I have checked the idle with a dwell tach, and it shows 600 rpm in park, which immediately drops to 480 rpm when placed in gear. If I manually increase the speed to 600 rpm, the idle smooths out and the car sounds normal. If I turn up the idle while in gear, it then increases to between 900 and 1,000 rpm when placed back in park.
The car does have factory air conditioning (which is disabled now) and therefore an idle speed increasing solenoid. I have not seen this activate when the car is placed into gear. Does anyone know if this is supposed to increase the idle speed when the air is not on but the car is placed into gear? Does any have any other suggestions?
I have checked the idle with a dwell tach, and it shows 600 rpm in park, which immediately drops to 480 rpm when placed in gear. If I manually increase the speed to 600 rpm, the idle smooths out and the car sounds normal. If I turn up the idle while in gear, it then increases to between 900 and 1,000 rpm when placed back in park.
The car does have factory air conditioning (which is disabled now) and therefore an idle speed increasing solenoid. I have not seen this activate when the car is placed into gear. Does anyone know if this is supposed to increase the idle speed when the air is not on but the car is placed into gear? Does any have any other suggestions?