QuestionQUESTION: I have a 1979 RX7 that just started running very rough at low RPMs when it cold. It smells like the carb is loading up with gas. It runs a little better when it warms up to normal operating temp. It seems to run fine above 3000 rpm when its warm.
ANSWER: Check the spark plugs and if you haven't recently change the ignition wires, NGK or Racing Beat brand. It's not outside the box to assume the metering system or the choke may have a fault but, basic maintenance can solve most drivability issues. Start there.
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QUESTION: Spark Plugs are fine and ignition wires were changed about a year ago. It has solid state ignition. No Points. Any other suggestions?
Thanks,
AnswerIf you can rule out ignition then look for a vacuum leak source (for which there can be many) then check the carburetor for proper operation. Clean everything with a carburetor cleaner spray, softly manipulate the linkage points and see if anything is binding or if anything seems unusual, resistant, etc.. It is an electronically controlled carburetor which was a bad idea from the onset so if it can't be blamed on something obvious and external then the internals would be the next place to look which means a possible overhaul and not an easy task, good carburetor technicians have gone the way of the dinosaurs. Unplug, inspect/clean and re-plug connectors to the carburetor.
Leak sources can be located by manipulating connections or even spraying penetrant at suspected areas while the engine is idling and listening for changes or variations in idle quality.
You may be surprised to find it is something quite simple.
A very viable alternative, if in fact you can trace the problem to your electronic carburetor is the Racing Beat/Holley conversion. Very simple by design and very reliable. Though not cheap, about twice the price of a stock rebuild it comes with a tuned intake, air cleaner and carburetor ready to go out the box.
