Toyota Repair: Hi Mike, I own a 1994 Toyota..., light flickers, random intervals

Question
Hi Mike,

I own a 1994 Toyota Corolla CSi Hatchback with a manual transmission and 175,000kms. It has an EFI 1.6L engine (4A-FE).

The problem started about a year ago with the battery light intermittedly flashing on then off every so often during driving. About 3 months ago the car started stalling. I "fixed" this by turning the idle up 500rpm over normal. It won't stall now, but at every set of lights when the car is at idle the engine revs will fluctuate between about 700rpm up to 2000rpm constantly dipping up and down between here despite no throttle input. Also now during acceleration the battery light will flick on and off rapidly seemingly at random intervals. At night all the dashboard lighting will occasionally flicker on and off as well in time with the revs. Please note that the car accelerates like normal, it is just at idle that there is a problem.

Car has a new battery, new battery terminals, new spark plugs, oil and air filter. I have also replaced the rectifier. Do you have any suggestions on what to replace next?

Thanks
Tony.

Answer
sounds as if there is air in the cooling system so it cant find the right idle .
Its getting a false signal to the efi computer from a sensor in an airpocket.
Run it with the heat on and radiator cap off at idle to see if it "burps" out the air.
The charge light flickers when the Alt is spinning to slow to charge.

Mike