adjusting air-fuel ratio

[fourwheel1]

I have a 98 12 valve and would like to know how to adjust the afc to get more fuel earlier. Any info would help.









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98 quad, 5sp. , 12 valve, isspro guages, shaeffer oils,

250 Hp, 505 ft. lbs, 317,000 miles - original!!!!!!!

 

[Todd T]

you can simply adjust the star wheel under the allen cap. or go all out and open the housing slide the plate forward and replace the housing with it all the way forward.



to do this you will need to center punch the tamper proof screw. then hammer a #10 or #15 torx bit into the head of it to get it loose.



once inside, slide the plate towards the front of the truck as far as it will go then when you replace the housing cover slide it all the way forward in its slots. to adjust the star wheel take out the allen screww cap that is on the top of the AFC housing and turn it towards the engine for more fuel earlier and away to limit the fuel.

 

[Joseph Donnelly]

If you just have to move the plate, scribe the original location. Then when you find the egt's are too high above 2400 rpm, you can move it back. The 215s are different, and have a race pump from the factory Better get the right uprate plate for it

 

[illflem]

Don't do any of the above without first installing an EGT gauge unless you like toasted engines.

 

[Pthomas]

#10 plate and medium tst afc spring!

After you get the egt gauge,

the #10 and tst afc medium spring with everything foward is full of G FORCE . the 10 plate has a great fuel curve, thanks TST! dont forget to set the governor lever rocker to the new plate !