I got the Walbro GSS340 pump and the wiring kit. Any advice?? I am inexperienced at this stuff so even basic stuff may be helpful to me! I plan on installing it myself tomorrow. TIA. :chevy Hopefully this will bring the 383 to life!

 

Just remember to depressurize the system before you pull the lines off the back. Other than that, the swap is fairly straightforward and easy. Be careful with the ruber lines in the back too, I had one split a little bit on me and I had to shorten it.

 

I purchased the same pump with the Plug n play harness. I plan on installing it next week. I'll check in to see how you made out.
Phil

 

Just curious, where are you guys buying this pump from and for about how much $$.

Also am I correct in thinking that this is a pretty easy install, done somehow through the fuel door in the back from up top?

 

The pump is a snap to put in, 10 minutes tops. I haven't replaced all the wiring yet.

For prices on the pump and wiring kit check out....... http://www.racetronix.com/





[Modified by Mr. Magoo, 11:07 AM 9/26/2002]

 

I did. I bought the whole kit from Racetronix. It truly is a plug and play system. Its not hard at all. Be careful runnign the wires over the rear suspension. Make sure its tucked up and tied very good. Look at all the pictures on the website since there are no directions (or at least there weren't when I bought one). I never did verify if there are any voltage chagnges. It won't make your car faster or run better most likely. The stock pump is very good.

Jason

 

Ok, the racetronix kit looks good. I'll be ordering one eventually. Now my stock fuel pump is good enough, so any Walbro pump will be overkill. I guess the question is for the extra $10 is there any reason to not go with the additional overkill of the 340 pump over the 307? I'm inclined to believe it wouldn't hurt anything at all to just get the 340.

 

They both flow the same up to 55PSI.

 

THIS WAS POSTED AWHILE BACK HERE ON THE FORUM, I THINK SCORP POSTED IT BUT NOT SURE.

REPLACING THE FUEL PUMP

Simple job!
1. Remove fuel pump fuse.
2. Run car until it dies of starvation.
3. Try to start car for 10 seconds to get it all out.
4. Disconnect negative battery cable.
5. Open gas door.
6. Use torx bolt to remove gas door lid and black part.
7. Disconnect all rubber hoses.
8. Disconnect wire connector
9. Use (I think 10mm) socket to remove bolts.
10. Pull straight up.
11. Carefully remove the fuel strainer from the bottom of the pump. Don't jerk on the strainer unless you have a new one ready. Note the angle and direction the strainer sock is pointing - you'll want to put it back on in the same orientation.
12. Disconnect the wiring harness from the pump.
13. Pull down to pull the old pump off. Catch the small metal can (surge suppressor) between the pump and the intake. Shake the can. If you hear fuel in the can, you're supposed to replace the can (I didn't).
14. Put the new pump on. Put everything back the way you found it.

Useful parts needed to do this right -
new fuel pump
new surge suppressor (the metal can)
new strainer
new fuel unit-to-tank gasket

The stock pump has a foam insulator wrapped around it that you should xfer to the new pump to reduce vibration.
When you install the new pump, make sure that the fuel sock is oriented the same way as before, otherwise it can interfere with the fuel float and screw up your fuel level readings. Also when you reinstall the sending unit/pump assembly, make sure you set the fuel pump inside the shallow recess area in the tank and don't get the float hung up on the same area.

 

The wiring harness will ensure that the fuel pump will provide maximum volume and in some cases extend pump life. A Walbro pump can draw twice as much current as the factory pump. The factory harness is undersized even for the factory pump causing voltage drop which in turn impedes pump performance.

The wiring harness can make your car run better / faster if your fuel pump is having trouble keeping up because of inadequate supply voltage.

The factory LT1 pump is better than the L98 pump but neither don't come close the Walbro GSS340 in performance.
http://www.racetronix.com/Fuel_Pump_Ident.html

Jack :cool:
Racetronix

Racetronix 94-88 C4 Kit
Racetronix 89-96 C4 Kit

 

I installed the 307 a while back and have been totally satisfied with the quality and performance. It also powers directly off the alternator and has its own fuse. Easy install, operates electrically the same as stock. I guess peace of mind is the bonus.

 

hmm...i wonder if mark is going to make it to the track tonight :p:

 

I'll be there, just don't loose your license on the way over buddy :lol:

 

:lol: :lol: :lol: :lol:

 

I've got the pump in now! It works great!! I haven't done the wiring yet, but it did solve my problem of fuel pressure dropping off at higher RPMs. WOOHOO no more super lean condition!

 

How are you progressing with the wiring. I also installed the pump,but now its time to do the wiring. With my old pump the pressure was dropping under WOT. I also noticed that the old pump would pressurize up to 52psi when I turned the ignition key to ON,but would immediately drop to zero in ~10 seconds. With the new pump the pressure stays at 52psi ,after the pump shuts off. This is a excellent start. Now, I need to check the pressure under WOT. Need to go to the track to accomplish that.
Phil

 

Installing the harness is a breeze!
Remove the cover around the gas fill cap.
Mount the relay and spiked ground lug as shown in the ad pic here using plenty of silicon grease supplied: http://www.racetronix.com/images/C4/...y_Mount-01.jpg
Run the cable with the Delphi connectors up the fill cap area and plug them in as shown here: http://www.racetronix.com/images/C4/...olts_RX-01.jpg
Run the wire with the fuse holder under the car along the driver's side and up to the alternator as shown in this ad pic: http://www.racetronix.com/images/C4/..._Hookup-01.jpg
Keep the harness away from hot headers / exhaust.
Mount and connect the fuse holder as shown.
Wire tie the harness in place to make sure it is secure.
Some people opt to run the supply line through the body side channel / molding. Either way is OK.
Install the battery nuts and body ground upgrade as shown in these ad pics: (use silicone grease on the body ground)
http://www.racetronix.com/images/C4/..._Ground-01.jpg
http://www.racetronix.com/images/C4/..._Hookup-01.jpg

Jack :cool:
Racetronix


[Modified by Racetronix, 11:23 PM 9/30/2002]

 

What HP level is this pump designed for?

 

Depending on your motor's BSFC, your fuel pressure and alternator voltage typical levels are 500-600RWHP with the Walbro GSS340M. An additional 100RWHP+ can be gained with a Racetronix Pump Booster. LT1 motors tend to require less fuel for the same given HP levels on a L98. LS1 is by far more efficient than your typical L98 or LT1. Blowers, Turbos and NOS require more fuel to produce best power and to ward off detonation.

Jack :cool:
Racetronix

 

I finished up the install today. Thanks for all the help!! :chevy