there is a front injector and a rear injector .I did not know the rule of thumb on the injectors .mine still work okay but it might be a good idea to change them .thanks

 

That is very strange that one injector will prime and the other does nothing. They both have the same pressure behind them and the both prime at the same time. So I would do the noid light just to verify the injector wiring is fuctioning. If it is, you found your problem at the injector. If it's the wiring harness, this starts a whole new discussion! It seems you have a good bunch of guys walking you through this, you'll get it! I've been running my 82 crossfire as a daily driver for over 10 years and once sorted, the CFI works flawlessly and is extremely reliable!

 

Noid light installed and get a single flash from both injector harnesses so I know I'm getting the prime pulse. Rebuild kit for the throttle bodies arrived today and new injectors via snail mail.

Is there a particular trick to removing the injectors from the throttle body? Drivers side will not come out easily!

Since so many suggest running a 85 high pressure pump and I'm sticking with a stock pump, what's wrong with setting the pressure regulator screws to the highest setting?

 

Use a flat bladed screwdriver to pop the injectors loose, use the injector tower as the fulcrum. You can set the pressure higher, but the pump may not be able to support over 12 psi at WOT. Your call. Most CFI's were set at 9-12 psi from the factory.

 

Sounds like you are on the right track. I'm still running the stock 82 fuel pump but the car does go flat lean after 5300 rpm. If you're not screaming it, you'll never notice.
Since you are tearing down the top of the intake I would strongly suggest one must improvement. Install the Felpro intake plenum gasket if it hasn't been done. Every CFI has vac leaks from the silicone GM slathered all over the plenum. Felpro didn't make a gasket until years later. This will save you many nightmares down the road!

 

Which way do you turn the screws for max pressure; my replacement OEM shop manual is delayed to to the winter snow storm!

 

I plan to as she has always had a cold idle miss that disappears once warm.

 

One step forward and two back:

Twisted the fuel line between TBs trying to break it loose to remove bottom half of TB; ideas?

 

YES...IF you REALLY TWISTED the steel line.....Then buy a new line withe fuel pressure gauge made into it it. If not....I may be able to find one for you...but by the time the smoke clears....getting a line with the gauge may be best for future issues.

IF the line 'just started' to twist and you caught it BEFORE it 'rolled over'....then HONESTLY...WHEN have encountered this...I remove BOTH throttle bodies so I can get to area easier and get them to loosen or free-up.

JUTS MAKE SURE you are REALLY PAYING attention when you install your new injectors...and WATCH OUT for that very thin narrow retainer.

Have you ohmed out the injectors that you have in it now and see what they read???? Test Across BOTH terminals.

I would ALSO verify that even though the NOID light shows you are getting a pulse signal.....WHAT voltage is actually at the connector that is for the injector that is NOT working???

I have a tool I use for the later year model Corvettes where I have to check for injector balance. Due to having 8 injectors....making sure that they ALL are within a very tight parameter of output....SO....each cylinder is getting the same amount of metered fuel. SO...IF you can keep the fuel pump running...and manually pulse the injector on the good one and it sprays....and the do the other one and it does not.....seems to make sense that it is shot.....OR...do nothing at all because you are putting in new parts.

AND for what it is worth....I have modified some open end wrenches so I can hold onto the fittings that thread into the throttle bodies WHERE the steel fuel lines attach....so these do not spin....while the throttle bodies are still attached to the intake top plate.

And I know this may seem CRAZY...but if you pull the throttle bodies for whatever you are doing and you have not replaced the top intake BIG PLATE gasket....NOW would be the time to do so. TRUST ME...it would be in your BEST interests to do so ( IF you know it has not ever been done recently)...And DO NOT be shocked when you go and begin removing jamb nuts for grounding points that you MIGHT run into an issue where the stud /bolts wants to come out and the nut stays lacked onto the stud. ( I have modified open end wrenches for these issues also) REGARDLESS of what hassles you run into...replacing this gasket is important. AND...IF you do...DO NOT take a brisket pad tool OF ANY TYPE and scrub off any stuck on sealer/gasket. THAT would be A HUGE MISTAKE. If anything you do...drag a single edge razor blade across the surface until they come clean.

DUB

 

Line is shot; know who sells with the gauge?

 

NOPE..the company of the link I posted is no more...so...unless you google it....I do not know if the companies that re-build/ the throttle bodies sell them or even offer them.

DUB

 

ebay sells 3/8 gauge ports for cheap you can splice in with rubber hose between the 2 tb's


http://www.ebay.com/sch/i.html?_from...port+&_sacat=0

 

you don't want max pressure you want 14-15 psi



GM TBI 220 & TBI 300
ADJUSTABLE FUEL PRESSURE REGULATOR
It has become common practice to remove the original fuel pressure regulator and replace it
with an aftermarket adjustable unit. While the advantages of being able to adjust fuel injector
pressure are not certain, adjustment does give the opportunity to change open-loop fuel flow
and trim the part-throttle mixture somewhat if necessary. The only situation in which a setting
outside the OEM specification may be necessary is after considerable modification to the rest of
the system. That said, the cost of purchasing and adjustable regulator may be wasted. Instead
of purchasing such a device, the original regulator can be converted to an adjustable type with
little difficulty.
Since the regulator must be removed in either case, that labor would be equal. For an
additional hour of labor, the adjustment hardware can be added. The cost of the hardware is
less than $1.00, unless you use exotic parts (stainless steel nuts and bolts, new diaphragm,
gaskets, etc.), in which case the cost may approach $15.00.
APPLICATION
This modification is outlined for GM Model TBI 220 and TBI 300 units only. The later TBI 700
units have an externally accessible regulator that does not require removal of the injector pod
parts and is not as adaptable to the modification. Those with the TBI 700 unit should research
the design of the system before attempting any such modification.
Tools Required:
T-10 Torx driver;
T-15 Torx driver;
Center punch and hammer;
1/4" drill and bits;
Flat mill file;
1/4-28 UNF tap;
Tap handle;
5/32" hex wrench;
Materials Required:
(1) 1/4-28 UNF x 3/4" flat head hex recess bolt;
Anti-seize compound;
Replacement TBI gaskets*;
Replacement regulator diaphragm*.
* - May not be necessary in all cases
IMPORTANT! - You will be working around liquid and vaporized gasoline, and you must open
the pressurized fuel system to accomplish this modification. This creates a hazard of fire or
explosion. Isolate the work area from any sources of ignition and ventilate the area well. Clean
up any spilled fuel immediately and wash body areas that may contact the fuel with soapy
water. Discard any fuel contaminated articles safely and appropriately.
Park the car in a place where you can work on it for a couple of hours. Assemble all tools and
supplies, and allow the engine to cool to a safe and comfortable temperature before beginning.
You may want to apply penetrating oil to the fasteners and components a couple of days in
advance to permit easy removal of fasteners and parts.
REMOVING THE REGULATOR
Remove the air cleaner assembly and expose
the TBI (Throttle Body Injection) unit. Apply
penetrating oil to the screws that hold the top on
the fuel injector pod. Allow this to soak while
you continue.
Follow the service manual procedure to relieve
fuel system pressure. This generally involves
disconnecting power from the fuel pump and
starting the engine to use the remainder of the
fuel in the line. Check your service manual for
specific instructions and precautions.
Once fuel pressure is relieved, loosen the Torx
screws holding the top on the fuel injector pod.
After all screws are loosened several turns, work
the top loose from the gasket. If you are
working with a TBI 220 unit, you will have two
injectors and two gaskets. A TBI 300 unit has
one injector and two gaskets. The secondary
gasket seals the fuel return passages and is
smaller than the larger main gasket. If you are
careful, you can remove these without damaging
the gaskets. A new gasket set is recommended,
but an undamaged used gasket may be
serviceable. Remove the top and regulator.
Clean the unit and make a mark along the
locating slot in the spring can to indicate the
factory position of the regulator.
MODIFICATION
Once the regulator is off the vehicle, the screws
on the spring cap should be removed. The Torx
bolts holding this cover in place are T-10. If a
screw is stubborn, it can be loosened by
grabbing the head with a small pair of pliers to
start its movement. Applying penetrating oil to
the screws will make the process easier.
Remove all the screws evenly to allow the spring
to relax as the cover opens. Take care to make
certain the gaskets/diaphragms are not sticking
to either surface and tearing. Once the screws
are removed, the cap should lift off.
The spring/diaphragm assembly should be
cleaned, then stored in a manner that will not
damage the highly polished valve face on its
lower side. The valve seat in the regulator body
requires the same caution.
The spring cap should have a screw at its
center. This screw is typically brazed in place at
the factory to prevent unintentional or deliberate
adjustment.
This brazed area must be drilled out to free the
adjustment screw. Using the center punch,
make an indentation at the center of the recess.
Using this center and the inside of the recess as
a bushing, drill the bronze out with a 21/64" or
‘R’ (0.339") drill. A 1/4" spot weld cutter also
works nicely if you have access to one.
Remove the screw and spring disc from the can
and unscrew the screw. At this point, you can
decide whether you want to keep the original
shoulder screw or replace it. You may be able
to file the top of the screw flat and cut a slot to
enable adjustment with a standard screwdriver.
If the screw was damaged in the drilling process
or you prefer a hex recess (Allen) screw for
adjustment, set the screw aside.
If you are using the replacement 1/4-28 screw,
you must drill the hole in the spring disc with a
7/32" or #3 drill and tap 1/4-28 UNF threads for
the new screw.
Install the screw into
the spring plate and
the spring over the
plate. Your assembly
should look like this.
The flat top of the
screw will bear the
pressure of the spring
just as the original,
and the recess in the
cap will prevent the
screw from wandering
too far from center to
create problems.
Reassemble the spring disc and new screw into
the cap. Insert the spring, gasket/valve disc
assembly, and align the parts. Press the parts
together by hand to assure correct alignment
and that the gasket is not being distorted or
damaged. Install the T-10 Torx screws and
snug them in place. Once you are satisfied with
the replacement, remove one screw at a time
and apply a light coating of the anti seize
compound. Tighten each screw to 20-24
inch/pounds when finished.
Adjust the regulator spring disc position to the
same point as your original marks to begin with.
Reassemble the regulator to the TBI unit in the
revers order of disassembly. If there is any
question about the integrity of the gaskets,
replace them. Connect the fuel lines if removed
and operate the fuel pump to test the system for
leakage. Turning the ignition switch to the RUN
position without cranking the engine should
cause the fuel pump to run long enough to build
pressure.
ADJUSTMENT
To increase the fuel pressure, turn the adjustment screw counter-clockwise. This will cause the spring to
exert more pressure on the regulator diaphragm and regulate at a higher pressure. Monitor your
adjustment with a fuel pressure gauge. A little adjustment should be all that’s necessary, 1-2 PSIG at a
time. You can verify your results with a scanner monitoring the oxygen sensor output at wide-open
throttle, or your time slips at the track.
If you have made substantial modifications and have a lean condition, this modification may be
beneficial. Remember, the pressure change will make the greatest difference at wide-open throttle. At
any other time, the ECM will attempt to adjust the injector pulse rate to achieve the correct oxygen
sensor reading regardless of fuel pressure. Pressure that is too far from the stock setting may have an
adverse effect on part-throttle performance if the ECM cannot compensate for the difference.
Unnecessarily high pressure will only make your in-tank fuel pump work harder than it should, potentially
shortening its useful life. If you think changing the regulator was fun, wait until you have to replace the
fuel pump.
Happy motoring.
06/06/2001 Vader

 

Are we talking permanent install? Rubber hose close to intake manifold and associated temps OK?

 

NO...it is NOT OK. (my opinion on this)...DO NOT USE rubber hose. That is a problem waiting to happen.

IF I had to use a hose instead of a steel tube ...it would have to be stainless steel braided.....and that would be IT...and the braided hose would have the correct AN fittings for it and NO hose clamps....BUT...that is even a stretch due to the way the line has to route.

DUB

 

i wouldn't bat a eyelash
just get the right hoses, you already have rubber hose like i said near the engine block
your ac hose, hold a lot more pressure

get good hoses, you already mucked up the crossover tube, it's finished, your decision has been made with your heavy hand

 

Thanks for your continued assistance!

New fuel lines ordered!

Make any difference where positive and negative leads attach to check voltage at the injector harness?

"top intake BIG PLATE gasket". Brand rec?

 

Am I going to need to "re-balance" the TBs when rebuild complete?

 

I'm getting 20 psi at the pump outlet and 14 psi at the fuel filter.

 

And any tips on disconnecting the transmission shift down cable from the forward (pass) TB. My apologies for 20 questions but working in the dark here w/o a factory shop manual (snail mail).