TBI

[rauscher at icst.com]

How to modify the TBI for Adj fuel pressure. I'll give it a try...

I don't have a TBI with me here, so bear with me when I'm vague.

Oh, all disclaimers apply, remember that there will be some fuel left
within the TBI, so open it up OUTSIDE, away from any flame sources!

The regulator is at the rear of the TBI, it is basically upside down, connected
to the upper cover. It is the round item in the center rear of the TBI.

Remove the top cover screws(8), these are the ones that are around the injector
pods along with the ones further back. The top cover should come off along
with the regulator. The regulator being attached to the top cover.

At this time, decide whether you can complete the task. Turn the top cover
over and observe the now upper portion of the regulator. Down inside of the
center hole will be a screw stud that has been tack welded to the housing.

This screw is the adjustment. You will need to grind/cut/drill away/out the
weld,
and possibly build a new screw.

If you decided to continue, then do just as above. Remove the four screws from
around the base of the regulator. Disassemble the regulator, it is lightly
spring
loaded, and don't tear the diaphram! Grind/cut away the weld and remove the
screw, make/modify the screw, and reassemble.


BobR.

P.S. I just looked at one during lunch, from a 2.8L GM truck. It looks as though
the screw wasn't turned as the adjustment, it was always fixed. There is a round
metal bracket that the spring rides on that was turned on the screw to give the
adjustment. A tab on this bracket was then bent down into a slot in order to
'lock' it in.

If this is the case, then you would have to make a new screw piece that will
allow
the spring tension to be changed. This makes it a little more difficult.

--

rparker at cafes.net wrote:

>the 4.3Z engine. I want to turn up the fuel preassure a little bit. I
>have been told that to do this you must drill out some sort of brass
>piece which is on the TB to get to a place to adjust it SO, HOW do you
>adjust it? I need a pretty thorough explanation if I can get one.

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