Ever since I got my '82 GSL it's had a little studder while maintaining a cruising speed or coasting. Seems more violent while coasting. If you give the motor just a hair more throttle to bring the load up it's fine. WOT is fine. It's a jerk that's intermittant and feels ignition related to me (new to wankel, not hot rodding.)

So I did plugs/cap/rotor/wires. And it still does it. All the vacuum lines seem to be in good shape. They had recently been replaced by the previous owner.

Any ideas? This something in the carb or something goofy with the ignition?

Thanks
-Paul

 

Try changing the fuel filter

 

has the engine ever been rebuilt?
if so what are the specs?

 

Read this and do the Shutter Valve test. Just to eliminate it from being bad. It's a very simple test.
http://www.mazdatrix.com/faq/shutter.htm

Assuming there is no corrosion on your cables and controller (That's why Rusty's does not work. it's all rotten).

 

Motor has 25k on a Pineapple Racing stock rebuild. New housings and upgraded seals. Otherwise it's stock.

I thought about fuel filter but since it's a carb, I'd have thought that WOT would be terrible if it wasn't getting fuel to the carb..?

I'll try the shutter valve test.
Thanks for the help!

 

LOL I love Mazdatrix sense of humor "easy to change"... then.. they mention they had to fabricate a couple of custom tools heheh. (it's hard.. well to me it is).

edit add: Oh btw I was just thinking in the service manual there should be a cruise control troubleshooting checklist.

 

"Assuming there is no corrosion on your cables and controller (That's why Rusty's does not work. it's all rotten)."

What do you mean here?

 

I did the Shutter Valve test per Mazdatrix/FAQ.

That hole is sucking alot of air. If I put my finger over the hole, the car idles down from it's normal 1000rpm to about 600 or so.

This hole:



Is it a safe assumption that the valve has gone **** up?

Thanks!
-Paul