C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

fuel pump not working

Thread Tools
 
Search this Thread
 
Old 11-13-2015, 06:07 PM
  #1  
WLRDLR
Heel & Toe
Thread Starter
 
WLRDLR's Avatar
 
Member Since: Mar 2012
Posts: 24
Likes: 0
Received 0 Likes on 0 Posts
Default fuel pump not working

My 93 c4 sat for 10 yrs. Dug it out ,put injectors in it, cleaned the tank, ran fine for 20 miles. Now it wont run. Checked the fuel pump fuses & pump but it wasn,t pumping. Checked the previous pump seperately, works fine. I could use some help w/this,THNX
Old 11-14-2015, 04:35 AM
  #2  
ANTI VENOM
Melting Slicks
 
ANTI VENOM's Avatar
 
Member Since: Oct 2000
Location: Spokane Valley WA
Posts: 2,158
Received 8 Likes on 7 Posts

Default

First thing I would do since you checked the fuse, is to check for voltage back at the pump. Pull out that rubber surround at the filler cap so you can get to the electrical connector. The fuel pump power wire should show 12 volts for approx 2 seconds after you turn the key to on, then it will go to O volts. If you have voltage and a good ground, then it's time to pull the pump. I believe the tan/white wire is the 12 volts positive and ground is black. The other wire should be the fuel sending unit. There is a fusible link and a relay to check at some point, but that is where I would start. Good luck.

P.S. you would have gotten more responses in the Tech/Performance section. And, I don't know how you determined the pump was not pumping. You also said nothing about the 10 year old fuel filter. It's behind the right front tire. These instructions were based on my 91 vette, they should be very similar if not identical to the 93.
Old 11-15-2015, 02:03 PM
  #3  
c4cruiser
Team Owner

 
c4cruiser's Avatar
 
Member Since: Dec 1999
Location: Lacey WA RVN 68-69
Posts: 34,873
Received 476 Likes on 423 Posts
NCM Sinkhole Donor

Default

After checking to make sure there is voltage at the pump harness, you will also need to check the fuel pressure at the rails. Connect a fuel pressure gauge at the Schroeder valve, turn the key to ON and see what the reading is. You may need to repeat that a few times as the pump will only run for 2 seconds if the engine isn't started.

A good working pump, a clean "sock" at the pickup, a clean fuel filter and lines that are not clogged should provide around 40 lbs of pressure and pressure should remain for awhile.

Get notified of new replies

To fuel pump not working




Quick Reply: fuel pump not working



All times are GMT -4. The time now is 02:33 AM.