[Home | Mail Archive | Join the mail archive | Photo Gallery ]

Mazda Rotary Pickup Forum
you are logged in as
profile | register | faq | search (active threads) | memberlist
Sponsored by:
Index > Engine/Drivetrain > Thread: Un-smooth idle
Thread: Un-smooth idle
mwpayne1


Redlining
Posts: 239
posted May 10, 2012 06:57 PM

Un-smooth idle

Hey guys, now that the truck is starting SO much better, I have a bit of a rough idle. Not enough to get close to a stall, but you can feel the vibrations in the cab and the shifter vibrates. The book says the air mixture is the top slotted screw on the carb, but the parts breakdown I got with the carb kit has this reversed. Once this is cleared up, is there any tips on adjusting idle and/or air fuel screws?

       
View IP (Administrators only)
Brad


Rotorhead
Posts: 1671
posted May 11, 2012 03:20 PM

Back when I had an Rx-3 carb I set the idle speed first via the air speed screw or whatever they call it.

Then set the idle mixture.

Fuel pressure & float level checked and tune up must be up to date for best results.
____________
-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge

       
View IP (Administrators only)
Chuyler1


Hauling
Posts: 140
posted May 11, 2012 05:29 PM

This may be unrelated but worth a check. My idle was pretty rough and while cleaning up the engine bay I noticed a few vacuum plugs were cracked from when the emissions were removed. I replaced them with new plugs and the idle smoothed out.

       
View IP (Administrators only)
mwpayne1


Redlining
Posts: 239
posted May 11, 2012 08:42 PM

Truck has new plugs, air filter, plug wires, rubber caps on carb, new OEM cap and rotor, and carb just rebuilt. Wonder which adjustment is which. I bet the slotted screw is the idle speed, the one below it is mixture. Like to know for sure before I start putzing with it.

       
View IP (Administrators only)
sparky


Redlining
Posts: 299
posted May 12, 2012 08:53 AM

A little off topic but something to consider. I have always experienced idle problems and tried cleaning jets, set float, and mess with mixture/air screws on stock carbs. After i upgraded ignition to DLDFIS never had an issue. Always a bood idea to take the top off the carb and check everything too.
____________
'77 REPU
Stock 6-port
T-2 tranny
Weber IDA 48
Alum Flywheel
3rd gen Torsen in rear end.
DLDFIS ignition

       
View IP (Administrators only)
mwpayne1


Redlining
Posts: 239
posted May 13, 2012 05:38 PM

Just found, of all things, a bad trailing coil. When I unsuccessfully tried to hook up direct fire, no wonder it ran like garbage. Both coils less than a year old.

       
View IP (Administrators only)
All times are PST (US)
Post New Topic    Post New Reply
Rate Topic:
Powerd By: BlazeBoard

[Home | Mail Archive | Join the mail archive | Photo Gallery ]
0.013631105422974 seconds processing time