I've got a 3.4 95 camaro that's running rich, I've replaced the EGR valve and have been thinking about replacing the Map sensor on it. But I've noticed the fuel rail vacuum at the back seems to be missing a hose. One hose runs into the t that comes up but the left side doesn't have anything and I can hear the air being sucked into it. I've looked all over to find a vacuum hose diagram and the only thing I can come up with is it's missing the accessories vacuum hose but I can't find where it's at in the engine bay at all to hook it back up. And none of the autoparts places sell replacements for them. Is it supposed to be like this or am I missing a vacuum hose and it's possibly causing the motor to run rich? I'd kind of like to know because I don't really want to buy something I don't need and none of the places around can scan my car without charging an arm and a leg.

 

vacuum leak will make the engine idle like crap

exhaust leak w/good O2's will make the engine run rich

are you sure it's running rich?

When were the O2's replaced?

 

No vacuum hose on the fuel pressure regulator (if that's off) will make the fuel pressure spike high and cause the engine to run rich. You need to download a vacuum hose schematic so you can see what's what.

 

 

Or...look at the one above! lol

 

02 sensors replaced last year, I'll check for exhaust leak. The diagram above is how I have everything but I can't find the "to acsry" hose that should be hooked in. I've looked all over the engine bay and can't come up with anything. It's running pretty rich I can drive 60 miles and use three gallons of gas. Or is this normal with these cars?

 

Okay the hose that I'm missing is supposed to come out of the wire loom that runs behind the plenum, but it's no where to be found tried opening up the loom but still no luck. Could I just close off that part of the vacuum?

 

if that is city mileage that is pretty good, if its highway mileage its terrible, if its combined its low as well. my 3.4 does 28 mpg on combined, but mostly highway, driving. its been a while since i drove only city driving but i think it was around 18mpg, and i get 30mpg highway.

 

It's city and highway, I drive about five or ten miles each morning then about 60 twice a week on the highway. Maybe it's an exhaust leak and that's what is smelling like gas. It just seems like it's using a lot of gas and I'm not really heavy on the pedal.

 

If you had an open vacuum source, one that affects engine performance, you would have a noticeably higher than normal idle. Do you?