ICV test

[LateFan]

Questions about the ICV on an '86 eta motor (2 prong plug) -

We cleaned it thoroughly. Plugged with my thumbs and shook carb cleaner in there. It buzzes with ignition on or running. It rattles when shaken. It clicks when 12V is applied to the pins.

We tested the throttle position switch at near-closed and WOT with a multimeter. Beeps at the correct times.

Can the ICV still be not functioning correctly, even if passes all that?

We still have some idle cycling up and down as it warms up. Working on vac hoses - we may not have found all the leaks yet.

Thanks for the help -

[jlevie]

Have a shop run a smoke test to look for intake leaks as they are the most common cause of the symptoms you report.

[LateFan]

Thank you. Just learning this car.

Can a very rich condition be related to that as well? It will run just right for 45 minutes, and then randomly the next day it won't start and is completely flooded. Sooty gas smelling plugs, sputtering, black smoke. Today it started fine, ran well, but did the idle cycling when out of gear.

We've replaced o2 sensor, most vac hoses and intake boot (need to do the smoke test), all filters, cleaned and gapped plugs, cleaned / checked the ICV and TPS, and checked the resistance on one of the temp senders so far.

If this is an important clue, it has a half tank of year-old gas, half new, and a can of seafoam in the tank. There is some whining from the fuel pump.

[jlevie]

The engine being flooded after the car has been parked when you attempt to start it would be leaking injectors. Old gas in the tank would result in the engine running poorly, but half being fresh should eliminate most of that. A whining pump is one that is worn. It may, or may not, work properly at present and it may last for a while or fail suddenly.

[LateFan]

OK - we will test those systems.

It also flooded when running the other day. Driven a couple of miles with no issues, up to temp, and sitting at a light it stumbled and quit. Completely flooded - likely washed down cylinder walls as the starter spun very fast with no start. Would kick over with WOT, but not continue running.

It finally started just after I disconnected the cold start injector plug, but that could be a total coincidence. It may have been sitting or cooled down by then.

[jlevie]

A bad cold start valve or bad cold start controls will definitely flood the engine.