82 Corvette: Installing 85-87 Fuel Pump
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82 Corvette: Installing 85-87 Fuel Pump
Aloha Everyone,
I'm planning to "update" the stock '82 fuel pump to the higher pressure '85-'87 model.
Would you know if the stock fuel rubber hoses need to be changed to the higher pressure rubber FI hoses or will the stock rubber fuel lines be okay ?
The rear Crossfire TBI has the fuel regulator to bleed off the excess pressure back to the fuel tank thru it's fuel return line so after the fuel pressure is set to 14 PSI the remaining 22 PSI will bypass back into the fuel tank return line.
Since the '85-'87 fuel pump puts out around 36 PSI, ordered the 8-40# adjustable fuel regulator from Xtreme-Fi on eBay with an in-line fuel gauge 1/8 pipe T-fitting to mount a Marshall 0-30# silicon filled fuel gauge between the twin TBI crossover fuel line. The adjustable fuel regulator can be adjusted from the top portion of the rear TBI without any hassles. Plan to make a custom fuel line to put the gauge in a better location than stock to clear the Crossfire air cleaner as latter will put a larger dual snorkel '84 magnesium air cleaner in its place as well as the '84 serpentine system.
The stock '82 pump seems to lean out under load when the TBI throttle plates are opened wider & produces a slight engine ping even with 91 octane. EGR valve working OK.
Replaced the top cover Crossfire intake gasket as noticed a small section of the old gasket was protruding out of place and checked torque on other intake manifold bolts as may have been a source of air leak. Re-adjusted the timing to 6 degrees BTDC, TPS voltage 5.25V, balanced the dual TBI's. 700-R4 TV cable adjustment is where it should be & tranny shifts at the right RPM. Engine still has a slight ping when putting load on engine so the '85-'87 fuel pump change is eminent if the stock fuel pump's fuel pressure cannot be increased after the fuel pressure gauge and adjustable fuel regulator is installed.
I'm planning to "update" the stock '82 fuel pump to the higher pressure '85-'87 model.
Would you know if the stock fuel rubber hoses need to be changed to the higher pressure rubber FI hoses or will the stock rubber fuel lines be okay ?
The rear Crossfire TBI has the fuel regulator to bleed off the excess pressure back to the fuel tank thru it's fuel return line so after the fuel pressure is set to 14 PSI the remaining 22 PSI will bypass back into the fuel tank return line.
Since the '85-'87 fuel pump puts out around 36 PSI, ordered the 8-40# adjustable fuel regulator from Xtreme-Fi on eBay with an in-line fuel gauge 1/8 pipe T-fitting to mount a Marshall 0-30# silicon filled fuel gauge between the twin TBI crossover fuel line. The adjustable fuel regulator can be adjusted from the top portion of the rear TBI without any hassles. Plan to make a custom fuel line to put the gauge in a better location than stock to clear the Crossfire air cleaner as latter will put a larger dual snorkel '84 magnesium air cleaner in its place as well as the '84 serpentine system.
The stock '82 pump seems to lean out under load when the TBI throttle plates are opened wider & produces a slight engine ping even with 91 octane. EGR valve working OK.
Replaced the top cover Crossfire intake gasket as noticed a small section of the old gasket was protruding out of place and checked torque on other intake manifold bolts as may have been a source of air leak. Re-adjusted the timing to 6 degrees BTDC, TPS voltage 5.25V, balanced the dual TBI's. 700-R4 TV cable adjustment is where it should be & tranny shifts at the right RPM. Engine still has a slight ping when putting load on engine so the '85-'87 fuel pump change is eminent if the stock fuel pump's fuel pressure cannot be increased after the fuel pressure gauge and adjustable fuel regulator is installed.
Last edited by 82CorvetteCE; Mar 2, 2010 at 01:32 PM. Reason: Corrected typo
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'82 Fuel line
Got a reply from Xtreme-FI and most stock OEM rubber fuel lines is good to 50 PSI if it is in good condition.
The rear TBI has the fuel pressure regulator,so setting it @14PSI the remaining 22PSI will bleed off from the rear TBI return fuel line to the fuel tank.
The rear TBI has the fuel pressure regulator,so setting it @14PSI the remaining 22PSI will bleed off from the rear TBI return fuel line to the fuel tank.
Last edited by 82CorvetteCE; Mar 2, 2010 at 01:25 PM. Reason: Added more info
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Stock Fuel Pump- Failed the Test !
Well, hooked up the 1 1/2" Marshall 30 PSI fuel gauge from Lopers Speed in Phoenix, AZ, an eBay seller, between the 2 TBI's & the fuel pressure is a paltry 9 PSI with the stock electric fuel pump that's about 3 years old ! No wonder I'm getting a slight engine ping when going up hills.
Had to purchase a brass T-fitting with 90 degree 3/8 fuel line fittings and also make a new fuel line to move the fuel gauge from under & away from the air cleaner. It's pretty tight down there.
The gauge sits just past the driver side intake and before the valve cover so can remove the valve cover without the gauge interfering & just cleared the air cleaner's stove downspout pipe.
The universal aluminum T-fitting from X-treme FI didn't work for me as it was a straight piece and needed the 90 degree bends on the fitting. It also had an ID of 1/4" with 5/16" connection tubes with a flared end for the 3/8" fuel line. Kinda small ID compared to the ID of the 3/8" fuel line.
Next step is to install the X-treme adjustable fuel regulator to see if it can adjust the fuel pressure up to 12-14PSI. Doubt the pressure will rise in which case the 85-87 fuel pump goes in.
Found out that TBI and TPI systems uses the same SAE rated fuel injection rubber lines.
Update: Adjusted stock fuel regulator with factory spring to the maximum spring pressure with the stock fuel pump, highest fuel pressure reached:10 PSI.
Regulator removal: While holding top cover upside down, use your thumb to hold the cover while removing the torx head screws. Same when putting the cover back after adjusting the adjustment screw.
I put a light coating of grease on the bottom regulator to TBI body dust cover gasket and the (2)top cover plate paper gaskets as well as the surfaces so it won't stick & break the next time I lift the cover off.
The top TBI cover has 5 screws: 3 long ones & 2 slightly shorter ones. Long ones go on the thicker side of the top plate; shorter ones go along the 2 sides of the injector. I put (1) long screw in the top cover to hold the "oval" paper gasket in place so it won't misalign or fall off the top cover while installing the cover back on the TBI body.
GM Service Manual recommends using 2 studs for guides, but found was not necessary to align the holes. Using the higher pressure spring onthe AFPR is another story as the spring is harder to compress.
Alas, test driving the Corvette @10PSI didn't cut it. Still a slight ping on load.
85-87 Corvette fuel pump model EP241 which uses a GM 2-pin plastic connector- PN #FP51 will going in next with the X-treme FI adjustable fuel pressure regulator.
Waiting on the FP51 connector being shipped which was left out of the EP241 fuel pump kit.
While waiting for the FP51 connector, installed the X-treme FI AFPR and set it to its lowest spring pressure. Managed to install the AFPR with thumb pressure applied to hold it down while securing it with the (4) torx head screws. Pressure rose to a stable 12PSI so appears the stock regulator spring was too weak. Will see how long the 12PSI lasts.
Subsequently adjusted pressure to 14PSI with the stock pump.
Few days later...pressure @11.5 PSI...time for a switch to the '85-87 pump with a more consistent PSI.
At 11.5 PSI on the factory pump, connected my ALDL USB cable to my laptop running WINALDL and found my stock ECM 1225550/chip may be running in open loop as no BLM/INT values in WINALDL but shows BLM/INT/O2 sampling averages. May be software giving incomplete readings. All sensors were up to snuff with no trouble codes present. Slipped in a ECM 1227747 and gave it some WOT up the hill....no ping so the the 1227747 spark programming little better.
Will save the EP241 fuel pump when the stock one dies out.
Another day at the funny farm...
Had to purchase a brass T-fitting with 90 degree 3/8 fuel line fittings and also make a new fuel line to move the fuel gauge from under & away from the air cleaner. It's pretty tight down there.
The gauge sits just past the driver side intake and before the valve cover so can remove the valve cover without the gauge interfering & just cleared the air cleaner's stove downspout pipe.
The universal aluminum T-fitting from X-treme FI didn't work for me as it was a straight piece and needed the 90 degree bends on the fitting. It also had an ID of 1/4" with 5/16" connection tubes with a flared end for the 3/8" fuel line. Kinda small ID compared to the ID of the 3/8" fuel line.
Next step is to install the X-treme adjustable fuel regulator to see if it can adjust the fuel pressure up to 12-14PSI. Doubt the pressure will rise in which case the 85-87 fuel pump goes in.
Found out that TBI and TPI systems uses the same SAE rated fuel injection rubber lines.
Update: Adjusted stock fuel regulator with factory spring to the maximum spring pressure with the stock fuel pump, highest fuel pressure reached:10 PSI.
Regulator removal: While holding top cover upside down, use your thumb to hold the cover while removing the torx head screws. Same when putting the cover back after adjusting the adjustment screw.
I put a light coating of grease on the bottom regulator to TBI body dust cover gasket and the (2)top cover plate paper gaskets as well as the surfaces so it won't stick & break the next time I lift the cover off.
The top TBI cover has 5 screws: 3 long ones & 2 slightly shorter ones. Long ones go on the thicker side of the top plate; shorter ones go along the 2 sides of the injector. I put (1) long screw in the top cover to hold the "oval" paper gasket in place so it won't misalign or fall off the top cover while installing the cover back on the TBI body.
GM Service Manual recommends using 2 studs for guides, but found was not necessary to align the holes. Using the higher pressure spring onthe AFPR is another story as the spring is harder to compress.
Alas, test driving the Corvette @10PSI didn't cut it. Still a slight ping on load.
85-87 Corvette fuel pump model EP241 which uses a GM 2-pin plastic connector- PN #FP51 will going in next with the X-treme FI adjustable fuel pressure regulator.
Waiting on the FP51 connector being shipped which was left out of the EP241 fuel pump kit.
While waiting for the FP51 connector, installed the X-treme FI AFPR and set it to its lowest spring pressure. Managed to install the AFPR with thumb pressure applied to hold it down while securing it with the (4) torx head screws. Pressure rose to a stable 12PSI so appears the stock regulator spring was too weak. Will see how long the 12PSI lasts.
Subsequently adjusted pressure to 14PSI with the stock pump.
Few days later...pressure @11.5 PSI...time for a switch to the '85-87 pump with a more consistent PSI.
At 11.5 PSI on the factory pump, connected my ALDL USB cable to my laptop running WINALDL and found my stock ECM 1225550/chip may be running in open loop as no BLM/INT values in WINALDL but shows BLM/INT/O2 sampling averages. May be software giving incomplete readings. All sensors were up to snuff with no trouble codes present. Slipped in a ECM 1227747 and gave it some WOT up the hill....no ping so the the 1227747 spark programming little better.
Will save the EP241 fuel pump when the stock one dies out.
Another day at the funny farm...
Last edited by 82CorvetteCE; Mar 14, 2010 at 11:42 PM. Reason: Updated Info
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Crossfire Injection TBI 400 Rebuild KIts
Bought the fuel regulator diaphragms and gasket set from SPR Performance as think my 28 year old ones will disintegrate on disassembly.
Contact SPR Performance for Crossfire parts at:
SPR Performance
Sean Rondeau
1111 W Morton Ave Ste 2
Jacksonville, IL 62650
dctrumpet & TBIPARTS on Ebay
www.tbiparts.com
217-473-4998
Contact SPR Performance for Crossfire parts at:
SPR Performance
Sean Rondeau
1111 W Morton Ave Ste 2
Jacksonville, IL 62650
dctrumpet & TBIPARTS on Ebay
www.tbiparts.com
217-473-4998
Last edited by 82CorvetteCE; Mar 4, 2010 at 02:11 PM. Reason: Added More Info
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