excellent suggestions -- I added them to the article.
I think I will try to set the pressure by using the O2 monitor as Jerry
talked about in his suggestions.
gene
>I have read the write up about the installation of the Howell TBI system on
>Gene Fisher's site with interest. The throttle body and injectors are stock
>Holley and are the same ones that are on the Holley kit that I installed in
>1993.
>
>A couple of suggestions: I put the gasoline return line into the rubber
hose
>(about 1: in diameter) that leads to the gasoline filler tube. I used a
>solder type rigid copper fitting that fit the ID of the hose and that had a
>small copper stub that the smaller hose would fit on. This saved me the
>drilling and tapping of the metal fill tube.
>
>I have never liked fuel hoses. They crack over time and can cause an engine
>compartment fire. I connected to the steel fuel line that runs along the
>front crossmember and then I ran a 3/8" steel line from the right front
>frame, along the frame to keep it away from the exhaust and to the right
rear
>of the motor box and then forward over the engine to the throttle body. If
>you remove the injector mechanism you will see how they have a hose barb
>fittings (inlet and overflow return) screwed into the throttle body
>injectors. I replaced the hose barbs with brass fittings that would
>accommodate direct connection to the metal gasoline lines, thus eliminating
>the hoses.
>
>I still have a hose going from the rear tanks along the frame rail to the
>front tube that goes along the front cross member but plan to replace most
of
>this hose next spring. Most of the rubber deterioration occurs where the
>heat is. That is why I didn't want any hose over the engine.
>
>My second gasoline filter is a large metal can type that came with the
Holley
>and is at the passenger right front frame and is easily accessible. It
>presently has two small sections of hose hooking it to the gas lines, but I
>am planning to look for a similar high capacity metal filter with fittings
so
>as to eliminate those two short hoses. I could also just use brass fittings
>with compression rings on the filter if I don't find a suitable filter with
>fittings.
>
>To adjust the fuel pressure at the injectors (Holley say about 18 psi)
you'll
>need a fairly accurate fuel pressure gauge. I have found that you can
>purchase a relatively inexpensive dial type air pressure gauge (0 to 50 psi)
>and unscrew the tire gauge fitting on the end and clamp a hose to it. The
>one I bought was under $5.00 at Pep Boys. I tested it for accuracy before
>using it on the TBI system and it was right on in the range I wanted.
>
>I originally went to the Holley TBI system because I had just moved from the
>San Francisco bay area (sea level) to Santa Fe (7000 ft.) and my GMC
>performed terribly. The TBI took care of all the problems that I was having
>with the carb at that time and has given me relatively trouble free service
>over the years. I have used it across the country several times in all
types
>of temperature, altitude, and terrain and feel that it is the best
>modification I have made to the GMC (6 wheel disk brakes are a close second).
>
>Emery Stora
>77 Kingsley
>Santa Fe, NM
>
Genef -- 77PB/ore/ca
GMC MOTORHOME INFORMATION
mr.erf
http://www.california.com/~eagle/
I think I will try to set the pressure by using the O2 monitor as Jerry
talked about in his suggestions.
gene
>I have read the write up about the installation of the Howell TBI system on
>Gene Fisher's site with interest. The throttle body and injectors are stock
>Holley and are the same ones that are on the Holley kit that I installed in
>1993.
>
>A couple of suggestions: I put the gasoline return line into the rubber
hose
>(about 1: in diameter) that leads to the gasoline filler tube. I used a
>solder type rigid copper fitting that fit the ID of the hose and that had a
>small copper stub that the smaller hose would fit on. This saved me the
>drilling and tapping of the metal fill tube.
>
>I have never liked fuel hoses. They crack over time and can cause an engine
>compartment fire. I connected to the steel fuel line that runs along the
>front crossmember and then I ran a 3/8" steel line from the right front
>frame, along the frame to keep it away from the exhaust and to the right
rear
>of the motor box and then forward over the engine to the throttle body. If
>you remove the injector mechanism you will see how they have a hose barb
>fittings (inlet and overflow return) screwed into the throttle body
>injectors. I replaced the hose barbs with brass fittings that would
>accommodate direct connection to the metal gasoline lines, thus eliminating
>the hoses.
>
>I still have a hose going from the rear tanks along the frame rail to the
>front tube that goes along the front cross member but plan to replace most
of
>this hose next spring. Most of the rubber deterioration occurs where the
>heat is. That is why I didn't want any hose over the engine.
>
>My second gasoline filter is a large metal can type that came with the
Holley
>and is at the passenger right front frame and is easily accessible. It
>presently has two small sections of hose hooking it to the gas lines, but I
>am planning to look for a similar high capacity metal filter with fittings
so
>as to eliminate those two short hoses. I could also just use brass fittings
>with compression rings on the filter if I don't find a suitable filter with
>fittings.
>
>To adjust the fuel pressure at the injectors (Holley say about 18 psi)
you'll
>need a fairly accurate fuel pressure gauge. I have found that you can
>purchase a relatively inexpensive dial type air pressure gauge (0 to 50 psi)
>and unscrew the tire gauge fitting on the end and clamp a hose to it. The
>one I bought was under $5.00 at Pep Boys. I tested it for accuracy before
>using it on the TBI system and it was right on in the range I wanted.
>
>I originally went to the Holley TBI system because I had just moved from the
>San Francisco bay area (sea level) to Santa Fe (7000 ft.) and my GMC
>performed terribly. The TBI took care of all the problems that I was having
>with the carb at that time and has given me relatively trouble free service
>over the years. I have used it across the country several times in all
types
>of temperature, altitude, and terrain and feel that it is the best
>modification I have made to the GMC (6 wheel disk brakes are a close second).
>
>Emery Stora
>77 Kingsley
>Santa Fe, NM
>
Genef -- 77PB/ore/ca
GMC MOTORHOME INFORMATION
mr.erf
http://www.california.com/~eagle/
