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Discussion Starter #1
Very strange. Cold start the idle kicks in high at about 1800 rpm then within seconds drops below 500 and keeps going down until a stall.

When engine warms up, rpms slow and it stalls at idle. With the ac activated the idle sometimes will go to 1100 and stay there...then at the next stop light the idle slows and it stalls again. With the AC on, the idle will 'cycle'...that is it will run at increased rpm...then drop to 5-600...then it will cycle back up to 1100...then down again, and so on.

It's not pulling any says all is well.

I have swapped out the ISC valve. No change. I have put in new plugs. Checked all the vacuum lines. I checked for a plugged cat by removing the o2 sensor to free up the exhaust. No change. swapped out the Os sensor. No change. Unplugged it. No change. I swapped out the ECU brain box. No change.

It seems to run fine at cruising speed. 1800 rpms and up, it runs strong. No hesitation on acceleration. mileage seems low- 17.4 city.

There seems to be a leak around the lower intake manifold...spraying starter fluid in there results in an rpm increase. But the gaskets are less than 6 months old.
And the bolts seem to be perfectly tight.

Plug wires are aftermarket. And while the toyota wires show high resistance, the aftermarket wires show very low resistance.

I am really puzzled here and could surely use some help.

It's a 1988, 5 speed, non-turbo. Headgasket, headwork performed about 7 months ago...

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