[WebCentral]

The other day I opened the hood of my wife's 93 Tercel, because it shakes on idle and stalls from time to time. I heard a hissing sound like vacuum leak, near the firewall, above the alternator, behind the engine. The mileage has drop considerably, almost halved. I tugged on all the vacuum lines, but didn't hear any change, I'm not inclined to change all the lines, is there any easy test I can do to determine the leak, if it's leak at all.

Thanks for your help.

 

[toyomoho]

You can use an unlighted propane torch that has the valve open.

Move it around the suspected leak area. The propane will be drawn into the leak and change the engine idle rpm.

A small hand held propane torch.

 

[Guest]

If you have the 5E motor, there is a small vacuum line that runs from the FPR to the intake manifold. Check to see if its dry rotted or broken. The FPR is the disc-shaped part located at the end of the fuel rail. Visual and physical are the best tests besides a vacuum gauge.

 

[Tyler9601]

Beleive it or not i solved the same problem by removing my gas cap. has the gas cap been changed recently? sometimes a generic model can cause too much pressure to build up and the gas will come out an airvent where you are describing. another possiblity.

 

[dusthead]

wow...if the gas cap is my issue...i'm gonna get officespace crazy on it. i have the same symptoms as the OP...except my stalling has become much worse, and since i'm stalling so much - i'm using a lot more gas. i bought a locking gas cap - probably like 6 months ago and starting having this issue 4 months ago.

i'm buring oil like a sum-bish, which i'm just settled that it's the valve stem seals. i just replaced the starter because it died. so the only thing thats pissing me off lately is the stalling and loss of power...which could be a fuel problem.

taking out my plugs and cleaning them with a steel-toothed brush isn't a bad idea either...but it's been raining all the time here...ugh.

hey, hope the OP got his issue fixed...i'll be lookin to see if anyone posted more on this thread....and post if the gas cap fix works for me.

 

[dusthead]

re-read my reply. yes the gas cap issue fixed it for me.

 

[silverhawk]

i was getting a hissing sound and a rough, high idle. it ended up being a severed wire for the sensor under the throttle body. It had rubbed against the power steering fluid resevoir and cut itself in half. The hissing sound actually ended up being from the sensor inside the throttle body.

 

[Pudgee25]

im having this same issue with the rough idle and a hissing sound around the back of the intake/ egr valve. i did check the lines there and they seem good. its driving me nuts. its a rough idle and its rough going into first gear. besides that, all the other gears or on the highway it runs good. i have a 94 3ee. i did notice some vacuum lines underneath the intake. i have to check those out. but i will deff try taking off the gas cap and starting it up and see if the works.