i JUST did a test, I noticed that I was only getting 8 miles per gallon.(spark plugs changed to new, O2 sesor changed to new,) the engine sounds like its mifiring(shaking at Idle) what are the possibilities of low mpg???

 

This might sound really dumb, but start up your car, and leave it in one spot and check for gas, My dads truck sucked gas like crazy because you couldn't notice the leak till it set for a few minutes...

Leaky exhaust will do it too, bacause FI loves back pressure.

 

hmm....if it sounds like its missfiring, you may want to check you plug wires. Perhaps you roasted one on an exaust manifold? I know its happened to me once... Does it seem like its missfiring while driving too, or just at idle?

 

just at idle

 

vacuum leak

------------------
Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

 

Isn't this in the tech section? Anyway, I still think it's time for a major tuneup. Have you done one? If you have, there's something else wrong...


------------------
-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

the car showed trouble code 35(IAC Idle Air Control). how do I fix this problem

 

Leave it on the L.I.E. J/K!!!!

There is a topic, short time ago about cleaning it.
It's located in the throttle body area.
I need to do that to mine.
What year you have.

------------------
Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

 

The idle air control valve is a very simple replacement with thorx nuts..takes about 5 minutes and costs around 45 bucks...there is no cleaning to it. if its bad its bad period. it has an electric motor in the selinoid. I kept popping 35 on my 3.1 and all the car needed to clear it out was a good long highway running....

 

thats all I need to do in order to clear that code?? will doing this help me with my low MPG problem??

 

Hi CHD,
I am taking my reponse from TomP's suggestion.
PERHAPS, some other models have different applications. In my old 1985 version, I understand (from a suggestion by Tom) that is the way to fix/clean mine.

------------------
Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

 

CamaroHunter, the 3.1 uses Torx nuts to hold the IAC in? The 2.8 doesn't; the whole IAC screws in/out of the throttle body. Thanks for the info!


------------------
-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!