Hard starting, low hunting idle, until it warms up? Options

[Geezer914]

1975 1.8L Ljet injection. Car is hard to start. It takes 3-4 tries and some time a shot of starting fluid. Fuel pressure gauge reads 30 lbs. in engine compartment. The rpm rises to 1800 rpm for about 15 seconds, then the idle hunts between 500 rpm and almost stalling out. After the engine warms up it runs and starts as normal. Vacuum hoses are tight. Comments? (IMG:style_emoticons/default/confused24.gif)

[timothy_nd28]

I don't think there is anything majorly wrong with your system. A low idle will kill power to the fuel pump, it's important to have the idle set correctly.

You tested the AFM earlier, when testing the fuel pump contacts (pins 36 and 39) you were instructed to move the AFMs' flap. Did you notice any drag or areas of catching as you moved the flap?

I think you need a good tune up. If it was my car, I would start with a valve adjustment. I would then test the vacuum canister on the dizzy to see if it holds vacuum then re grease the breaker plate. Pull a vacuum on the dizzy's canister, and verify by watching the arm moves the breaker plate smoothly. Next, adjust the dwell angle so it's spot on. From there, I would verify and adjust the timing.

After that, I would pull the bleed screw from the throttle body and flush the internal passage with carb cleaner along with the butterfly and insides. Next, set the idle, follow exactly what the manual says to do. Once the engine is running, spray starting fluid around the oil tower assembly, fuel injectors, intake base gasket, intake plenum, throttle body rubber doughnut, then the rubber S boot. Observe for any change in engine RPM as you spray these areas.

If you still have a hunting situation, I would suspect it's a lean idle hunt. I've been seeing a trend with today's fuel formulas causing our engines to run lean with the stock AFM settings. You will need to borrow a mobile style air/fuel ratio gauge before you attempt to make any adjustments to the AFM. Contact Malcom2, he has a bible of the AFM (pdf form) which will help aid you in adjustment.

I really feel you should attack this problem methodically by starting with a basic tuneup.