Okay,
I'm having some sort of fuel delivery problem (I think) The idle will plummet to 500rpms on some start-ups, and then just chug until you give it some gas and then the idle goes to normal. I'm replacing the fuel filter this week.

But,
The question is:
When I remove the gas cap while getting gas, should it make a "whoosh" sound or not?
Sometimes mine does, and other times it doesn't.
This may sound weird, but the times it doesn't make the noise, it seems to not run very well.
Thanks guys,
Jason

 

Not sure what vehicle you have but the whoosh depends on temperature. When its warm out the tank will build pressure. A bad fuel cap can cause emissions problems but rarely running problem. I would look elsewhere for your problem. What engine are we talking about?

 

Sounds to me like the gas cap isn't sealing effectively. Unless it seals well, I know that later Tacos will throw a CEL. This has been an issue for people wanting to add aftermarket locking gas caps. Sometimes the aftermarkets don't seal as well as the OEM cap, and CEL's arise.

 

http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

What engine do you have? Check out that link, it probally a TPS out of adjustment.

 

Sorry Guys,
It's a 92 Runner 3.0 automatic. It only has 40k on it, and only had 20k 6 months ago. (Local executives car, who traveled overseas 9 months a year since 92) I thought this was such a great find, but It is realy starting to run bad, it has little pickup (compared to when I first got it) and the engine sometimes (often) pings under acceleration. Something is definately wrong. I took it to 2 garages, the second being the dealer I bought it from (Toyotas garage) They both said "the valves must have some carbon on them, clean it off." The only advice given was to run some injector cleaner and some good gas through it. (How will this clean the valves?)
I had already run seafoam through it, and it seemed to run better while it was in the tank, but returned to normal crappy running after refilling.
I've changed the plugs, wires, cap, rotor, about 10k ago. Air filter 1k ago, checked timing, now what?
Another problem that started along with this is that the voltmeter moves back and forth whenever I come to a stop, and the lights dim, and the heater fan slows down until I get running again. The meter never goes below the low "operating zone" mark, but it does swing back and forth rapidly withing the "normal operating zone."
It didn't do any of this stuff when I bought the vehicle.

Thanks for your time,
Jason

 

Sounds like you have a charging system problem. I would bet a beer that once you figure out what the problem is there your engine will run better. Check all your batt cables and connections. Have the battery and alternator tested.

 

After I've been driving, I can hear a hissing coming from my gas cap. As soon as I open it, pressure from the gas tanks is released creating the "whoosh" sound as well.