No power to fuel pump
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,631
Likes: 4,076
From: Cape Coral, Florida
I did a YouTube video recently on checking the fuel pump circuit on the relay end...if you have questions let us know...quick check of the pump circuit is to jump pins 87 and 30 with the relay removed...if the pump operates that half of the circuit is good...if not let us know !!
P.S. In the video I'm using a test light to check the grounds...I use an old headlight bulb (pictured) to "load" the ground circuit...if the light is not bright there is not enough current flow going through the wire...GROUND RESISTANCE CHECKS USING AN OHM METER IS NOT THE WAY TO CHECK !!!...you can get a bulb (55W) at the "Zone" for a few dollars !!...and BTW what issues are you having "cranking no start" ??....use should include the info about your car such as year and mods in your profile !!...this helps us help YOU !!!
Last edited by C5 Diag; Jul 3, 2019 at 08:37 AM.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,631
Likes: 4,076
From: Cape Coral, Florida
You "may" have a bad crank sensor !!...you have no spark and fuel injectors will not fire if bad...a quick check when it's acting up is to look and see if your Tach is moving during cranking...if not the crank sensor is not sending ignition signal to fire the coil packs...you can also pull a plug wire off the coil and hold it about 1/2 inch from the coil pack...have someone crank the engine and see if you have spark...I don't know how your "skills" are but if you have a test light connect it to battery POSITIVE and remove the connector off an easy injector....while someone cranks the engine over touch the tip of the test light to the striped wire...that is a "pulsed" ground...the PCM grounds that wire !!....the test light will dimly blink if you are getting injector pulse as the motor cranks...sometimes hard to see in bright daylight !!...I don't know why you thought the pump was bad but the pump will however prime for 2 seconds with key ON but IF you try to start the car pin 86 of the fuel pump relay will not be remain energized because of the possible bad crank sensor so if you had a fuel pressure gauge hooked to the fuel rail the fuel pump pressure will drop like a rock during cranking !!...any questions give us a shout !!
Last edited by C5 Diag; Jul 3, 2019 at 11:08 AM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski