guys, my engine has been idling rough lately, I am noticing a hissing noise coming from behind the intake manifold, and I have lost a little bit of acceleration, plus a little bit of backfire. Now I know thaT Backfire is caused by leftover fuel that wasn't burned.

so my question is, Is there some kind of sensor calling for more fuel? Is there some kind of vacuum hose loose?

any ideas would be helpful

oh and I've heard that the check engine light usually relates to pollution control devices in the engine.

please help me with any ideas.

-Jim

Most probably the vacuum hose to the fuel regulator.

i may be round.

THe MAP sensor would not do this since you have a very low pressure drop occurring to give you that hiss.

If it is the vacuum hose to the fuel regulator, you will run rich and idle ruff. I call that good/bad fuel addition.

I use to run my 4AGE 20v Black top like that, except I block up the vacuum hose

whey did you run it with a blocked up vacuum hose, is it because it tricks the regulator into adding more fuel

thus the rough idle?

yep

But it is kind of strange since the vacuum is needed to add more feel up top as it open the diaphram some more to let more fuel through.

I had to block the hose because the car was now getting extra air which made the engine run lean, hence the increase in high idle to compensate for than.

But this is the 4age 20v.

My advice to him is to him is to check all vacuum hoses. If you have a map sensor, check the host you to that.

Again, I am not familiar with the 7afe

The check light is relate to problems the ecu is having,. It notify when something is wrong.

Thank you for your help

ok, I located the leaky vacuum hose, and replaced it, while I was back, there I also cleaned out my intake(ewwww)

but.... my check engine light is still on

do I have to reset something, or is there something else gone wrong with my car?

Pull the batt cables and press the brake. Give it about 5 minutes and put it back on. You should have reset the light by then.

-Bryan-

maybe that's te O2 sensor.
If it doesn't work properly for sure you'll have some air/fuel mixture problems.
It checks for the a/f ratio and it require more or less fuel depending of how rich or lean is the mixture. check for it.
As Ed said shouldn't be the MAP sensor, also cause if it doesn't work, your idling is fine but as you try to accellerate the engine stalls and can't raise RPMs due to a basic data missing.(it can't read the quantity of air entering in the manifold)
Hope this helps!!!

thanks guys, but it does seem like it idles fine and as I accelerate it slumps for a second.

I'll take a look