RANDOM no spark / start 1993 Toyota Camry 2.2

[AccordCodger]

When the problem first started, removing the gas cap would release either built up pressure -or- vaccum. The car would run well the rest of the day.

Until now, I assumed this was just a random thing that was more concidence than fact.

Is their something on the Camry that does cut out ignition if there's no pressure / too much pressure in the fuel tank?

I very much doubt it. And you said that used to be the case? If not now, then apparently it's nothing to do with that. But it's easy to check: When the car has been standing for a while (days) there's no pressure in the tank. And obviously the car is supposed to start then! So - remove the gas cap, and see if you have a spark. If not, then it's not connected to what you describe.

[km7648]

Originally Posted by Brian R.

Try replacing the tank cap.???

I did that at the beginning. It didn't change anything at all.

Are there any fuel tank sensors or switches that might signal the ECM to not send power to the distributor or ignitor?

[DFBonnett]

Originally Posted by km7648

I found the ignitor (thanks) and replaced it with a used one from the local wrecker.

Any possibility the used ignitor is DOA? Just a WAG.
FWIW
YMMV

[km7648]

This morning, I found that I had a plugged charcoal cannister.

There's one line that feeds the cannister's check valves that control fuel tank high pressure and high vacuum (both symtoms that I had).

It starts right up now, runs great (in the garage so far) and still has me puzzled.

Why the heck does the high fuel tank pressure or high vacuum caused by the canister cut out the spark?

Is there in fact something that tells the ECM "don't run" under these conditions?

[Brian R.]

Here's some reading for you - courtesy of the FAQ thread.
http://www.autoshop101.com/forms/h20.pdf
http://www.autoshop101.com/forms/h22.pdf
http://www.autoshop101.com/forms/h23.pdf
http://www.autoshop101.com/forms/h24.pdf
http://www.autoshop101.com/forms/h25.pdf
http://www.autoshop101.com/forms/h26.pdf
http://www.autoshop101.com/forms/h27.pdf

[km7648]

Thanks a bunch for all of your help.

It continues to start and run (as it should).

[RIP]

Thanks for keeping us up to speed. This is certainly a problem and a fix worth remebering. It's one for the "I'll be damned" list. Glad to hear all is well now.

I've read some believe toping off a gas tank can destroy a canister. Could that be why yours was plugged? I have a 94 and 87 and top them off all the time. Not absolutely to the brime but, some. What a canister has to do with no spark is still a mystery to me. Well worth remebering though. Cheers