Old 10-09-2012, 02:14 PM   #1
Devs93
Administrator
 
Devs93's Avatar
 
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 :http://www.thirdgen.org/tpimod2

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.



UPDATE;
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.
Later.
__________________

93 ecsb 5/7 2 tone shaved smoked lights hids and leds flowmaster and some more 295/50 245/50
Deven
http://www.gmt400.com/forum/showthre...B-Build-Thread
FB
http://www.facebook.com/#!/profile.p...00001465284578
Negative Altitudes Draggin That Shit Since 2006
Devs93 is offline   Reply With Quote
Old 10-10-2012, 10:16 PM   #2
stargazer7467
Full Access Members
 
stargazer7467's Avatar
 
Join Date: Oct 2012
Location: Hartford City, IN
Age: 39
Posts: 55
Send a message via AIM to stargazer7467
Default

having the injectors sonic cleaned by a diesel shop or whatnot would most likely net you a nice gain. Not too much hope out there for side feel injectors.
stargazer7467 is offline   Reply With Quote
Old 10-11-2012, 08:17 AM   #3
Bearcat91
Full Access Members
 
Bearcat91's Avatar
 
Join Date: Oct 2012
Location: Cinci Ohio
Posts: 354
Default

Whats stage 2?!
Bearcat91 is offline   Reply With Quote
Old 10-11-2012, 10:16 AM   #4
Devs93
Administrator
 
Devs93's Avatar
 
Join Date: Oct 2012
Posts: 780
Default

I will eventually get the ultimate tbi mod copied over
__________________

93 ecsb 5/7 2 tone shaved smoked lights hids and leds flowmaster and some more 295/50 245/50
Deven
http://www.gmt400.com/forum/showthre...B-Build-Thread
FB
http://www.facebook.com/#!/profile.p...00001465284578
Negative Altitudes Draggin That Shit Since 2006
Devs93 is offline   Reply With Quote
Old 10-11-2012, 10:54 AM   #5
Cablguy184
Junior Member
 
Join Date: Oct 2012
Location: Rankin County, Mississippi
Age: 47
Posts: 11
Default

Got any great info like this for the EFI ??
__________________
Randal Johnson ... Admin for Down South Bass Productions ... Team Linear Power / For the Love of Music
Cablguy184 is offline   Reply With Quote
Old 10-16-2012, 01:03 PM   #6
Bearcat91
Full Access Members
 
Bearcat91's Avatar
 
Join Date: Oct 2012
Location: Cinci Ohio
Posts: 354
Default

More TBI mods

http://www.tbichips.com/
__________________
Geoff
Bearcat91 is offline   Reply With Quote
Old 10-17-2012, 03:32 AM   #7
Red91
Full Access Members
 
Red91's Avatar
 
Join Date: Oct 2012
Age: 30
Posts: 285
Default

I am tempted to take a similar approach to engine mods as he did with his project "Plum Crazy" just something simple and reliable.
__________________

My Facebook
Red91 is offline   Reply With Quote
Old 10-17-2012, 08:46 AM   #8
Bearcat91
Full Access Members
 
Bearcat91's Avatar
 
Join Date: Oct 2012
Location: Cinci Ohio
Posts: 354
Default

His chips seem legit too! I wish my 305 had close to that power.
__________________
Geoff
Bearcat91 is offline   Reply With Quote
Old 10-17-2012, 11:03 AM   #9
Red91
Full Access Members
 
Red91's Avatar
 
Join Date: Oct 2012
Age: 30
Posts: 285
Default

Yea I have heard nothing bad his chips or his service either.
__________________

My Facebook
Red91 is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump