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Old 10-09-2012, 02:14 PM   #1
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Join Date: Oct 2012
Posts: 780
Default Stage 1 TBI mods

Hey all, Got bored waitn for my new dist to come in and I've seen alot of questions regarding the process, so I started this.
This is bone stock.

Remove the TBI, 13mm bolts 1 front 2 back. Unplug sensors and hoses. The fuel supply and return nuts should be 5/8". If you want to keep the cruze control then skip this part. You will need to get a smaller air cleaner or just keep the riser and not lower the air. Remove the throttle cable bracket, 13mm bolt front 14mm nut on the back. The cables come off the linkage pins with little clips, don't lose em. Separate the cables from the bracket by squeezing the front tabs together and sliding them out of the openings. Cut down the bracket where the cruze cable link was above the throttle slot so the air cleaner will fit down on the top of the TBI, deleting the riser.

Remove the fuel meter assembly. Just 3 screws 1 front 2 back. You'll need a torx T-25 driver. Next the fuel supply and return ports 3/4 wrench.Easy.
Next there is a butterfly adjustment screw covered by a pressed plug. I drilled this out. Start by flattening it with the grinder then drilling with a 1/8" bit working up to a 3/8" bit. This is to manually reset the IAC. To do that go here :

Using an air angle grinder or dremel tool begin smoothing out ridges working in a rounding way. Go slow and easy. working from the inside out. I started with a 60 grit wheel and worked up from there to a fine grit polish wheel.

Smooth out all the sharp edges around the ports widening as you go.
O.K. The edges are ground out wider and more smoothly all the way around giving a more open passage for the air. Cleaned up the entire top of the TBI leaving the aircleaner tabs for alignment. That's bout it! Its pretty simple. Took about an hour.

Clean the body well with carb cleaner or acetone. Blow out the all the ports with compressed air. Replace the fuel meter and re-install.

The air cleaner will fit directly onto the top of the TBI and line up with the tabs. The throttle bracket now has plenty of clearance. With the air cleaner sitting around the fuel ports instead of above them the air has a much cleaner, shorter path to the fuel.
Last thing. The wingnut bolt for the air cleaner will now be about an inch too long so it will have to be replaced or cut down if you want to keep the stock cleaner. I'm going to switch to an open unit with a taller filter instead.

Next stage will be the fuel regulator and pressure gauge. I haven't decided which way I'm gonna go on the reg.
Thanx y'all.

Got sidetracked by a distributor snafu but I finally got her goin. Very noticeable difference. Throttle response is cleaner. Acceleration is far smoother, and as far as power increase, Lemme put it to u this way; I got 3.42 gears in the arse, so I won't be liftin the front rubber anytime soon, BUT, I had to relearn my clutch release to keep from bangin my noggin on the headrest!
Stage 2 coming soon. I think I'm gonna go with the 18lb spring in the reg and I got my pressure gauge in today.
93 ecsb 5/7 2 tone shaved smoked lights hids and leds flowmaster and some more 295/50 245/50
Negative Altitudes Draggin That Shit Since 2006
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