Sprayin86

ok here's the deal. i have an 86 gt. i just completed the MAF swap. however this problem was present before the swap. i have an air/fuel gauge on my car and when the car is cold i can turn on the key and not even start it and it maxes out to rich. i can start it and once it warms up it will slowly but surely creep all the way down to lean. it doesn't bounce back and forth at idle like it should. i can hook up the scanner and it reads 41 and 91 system rich and 33 egr valve. anyone have any ideas. i don't think my gauge is bad as it has only been in the car since last summer and the O2 sensors are new as well. i appreciate any insight that can be given.

Sprayin86

i left this out. when i get out on the road and lay into it at wot its fine and goes to stoich, but when at about half throttle it stays in lean according to the gauge

schwindty

What kinda gauge to you have a AF Ratio Gauge? Wideband 02? You need to check with a Fuel Pressure Tester to get a exact reading

stanglx2002

For the EGR valve go to my teck articles link and read my article about Smog Deletion that should help with the EGR problem which is probably part the rich lean problem too. If that doesnt fix the rich/lean problem take the O2 sensors out and take a torch to them and clean them off and put them back in. Make sure to reset the computer after you do this so the computer can reread all the sensors. When you start the car dont touch the gas just let it idle for about 3 minutes.

preciousroy

when an o2 sensor is cold it will not read correctly, so if its stuck at rich till its warmed up i wouldnt concern myself with that. the fact that its stays lean when warmed up is pretty much telling you you have a prob. you said it goes to normal at wot, so i would double check for any vacuum leaks, spray brake clean around intake gaskets and vacuum lines and watch your a/f meter. i say its a vacuum leak because if its going away at wot, that means that your reducing the vacuum in the manifold, and a vacuum leak sometimes stops leaking when that suction power is lost, whick means the maf is reading the actual amount of air thats entering the engine, and will run at proper a/f. at idle, high vacuum means high suction, which means easier for air to get sucked through an intake gasket, or a small crack and such...