87 Corolla rough idle

This car has been in the family about 4 years starting with my oldest son,now my youngest son has inherited it,it has been having an rough idle issue since we had the car...but could never really pinpoint the problem,swore it was a vacuum leak,it would run for a long time like a sewing machine and according to my son sometimes when driving the car up a hill it would stumble (miss),and when it did this it had a rough idle and would want to die,i sprayed carb cleaner around the base of carb and did detect a vacuum leak when it was acting up,i pulled the carb and replaced the gaskets,still seem to have a vacuum leak,i rebuilt the carb and it still ran rough,but the odd thing is when its idleing rough i shut the engine off wait 10 seconds and start the car up and it runs fine...........could it be a timing belt issue or does this car have a chain......thanks in advance.jp

Reply to
JohnP
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I have a 1986, which should be almost the same, mechanically (4-AC engine), and it has a timing belt.

The Toyota manual says that rough idle or stalling can be caused by wrong idle speed, a clogged slow jet, wrong idle mixture, fuel cut solenoid stuck closed, bad fast idle speed setting (only for cold engines), choke valve open too much (cold engines), EBCV open, EBCV hoses, or outer vent control valve opened. The EBCV is a solenoid operated air bleed for the carburetor and is a cylinder at the passenger front side of the engine compartment. It should be closed when the engine is cold or idling. The outer vent control valve is located just above the charcoal canister at the driver rear side of the engine compartment, and with mine the short L-shaped hose had become soft and had split open.

I had a problem with bad idle, hot and cold, caused by a tiny piece of rubber flaking off from inside the fuel hose between the filter and carb and clogging the float valve. It caused trouble only because I had installed an aftermarket carb kit a few years earlier whose float valve had no filter to keep out such debris. Also I was told that the o-rings from the solenoid fuel cut valves can tear during installation and clog passages. Those o-rings in the aftermarket kit were rock hard and brittle.

The Mitchell manuals that some libraries carry (print, CD-ROM, or online -- the print version is the best) give almost the same fuel/ emissions information as the Toyota factory manual for this car does.

Reply to
larry moe 'n curly

In my experience, the online Mitchell is about as useful as a Chilton's book, not at all worthy of the name that appears on Mitchell's excellent paper manuals. On CD-ROM I've only seen the body manuals, which seem good.

Reply to
clifto

I see you've 'migrated' also! Guess what?! No OT posts!!! Think of it! We can talk cars!!!!

Reply to
Hachiroku $B%O%A%m%/(B

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