C4 General Discussion General C4 Corvette Discussion not covered in Tech

Fuel problem - Help

Thread Tools
 
Search this Thread
 
Old Apr 8, 2010 | 11:46 PM
  #1  
djdeep73's Avatar
djdeep73
Thread Starter
Intermediate
10 Year Member
 
Joined: Apr 2010
Posts: 49
Likes: 0
Default Fuel problem - Help

Hi Just checking to see if someone knows what this problem may be and if its pricey.

Just bought my first vette a 1987 in great condition. The only issues that it has is that the cluster seems to indicate the fuel is full and only noticed it after driving it 100 miles and and the meter never lowered.....so its stuck on full.

The next issue is that the car seems to have a hard time starting after shutting it off after the first start of the day. It cranks for about 3-5 secs before it finally starts.......is this normal on this car ? Do i need to pump the gas before starting it ?

thanks for any help anyone can provide on any of this.
Reply
Old Apr 9, 2010 | 02:35 AM
  #2  
Frizlefrak's Avatar
Frizlefrak
Race Director
20 Year Member
 
Joined: Dec 2000
Posts: 17,551
Likes: 26
From: El Paso Texas
Default

Issue #1. Fuel gauge. See my tech article on this

http://forums.corvetteforum.com/c4-t...h-article.html

....remove the sending unit and clean the contact and windings. This solves about 90% of all fuel gauge issues. I did it on my 84 back around 2001 and the gauge is still working fine. Takes less than an hour to do the procedure.

Issue #2. Long cranking times are usually due to a bad fuel pump relay. When the relay fails, the system relies on a backup....the oil pressure switch. If the relay is dead, cranking the engine builds oil pressure...when it reaches about 4 PSI, it closes the fuel pump circuit via a secondary path and energizes the pump. NOTE: They are wired in parallel, not series. If the relay is functioning, the engine will start and run with zero oil pressure. The OP switch is NOT a failsafe to prevent engine failure if oil pressure suddenly drops.

Pumping the gas pedal will have zero effect on anything on an EFI equipped car. In the old carbureted days, this activated the accelerator pump in the carb....which sent an ultra rich mixture into the engine. Not so on EFI. The ECM decides what the fuel ratio will be based on input from the sensors in closed loop, and from (some) presets in open loop.

Clean your sending unit, replace your fuel pump relay, enjoy your car.
Reply
Old Apr 9, 2010 | 06:52 AM
  #3  
chuck13's Avatar
chuck13
Pro
 
Joined: Aug 2007
Posts: 600
Likes: 0
From: been there done that
Default

its a corvette.of course its gonna be pricey!
Reply
Old Apr 9, 2010 | 08:58 AM
  #4  
j-vette's Avatar
j-vette
Le Mans Master
10 Year Member
 
Joined: Jul 2009
Posts: 8,041
Likes: 2
From: EOF ★ Kaliforniastan ★
St. Jude Donor '10
Default

Originally Posted by chuck13
its a corvette.of course its gonna be pricey!
Reply
Old Apr 9, 2010 | 09:27 PM
  #5  
Chapindad's Avatar
Chapindad
Racer
 
Joined: Jan 2007
Posts: 322
Likes: 0
From: Chapin South Carolina
Default

Learn to do things yourself and you will be happy. The fuel sender unit is very easy. It is cheap if it can be cleaned but if someone screwed it up then you will need to purchase anew one and that is about $300 on ebay. I have not done a relay so I do not know the cost.
Reply
Old Apr 10, 2010 | 12:57 AM
  #6  
RRT vette's Avatar
RRT vette
Le Mans Master
15 Year Member
 
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Default

I agree with everything Frizlefrak posted. I will add one other thing.

Your 87 is equipped with a cold start injector (9th injector).

Read the thread below for lots of info on it.

http://forums.corvetteforum.com/c4-t...old-start.html
Reply

Get notified of new replies

To Fuel problem - Help





All times are GMT -4. The time now is 04:53 PM.

story-0
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-1
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-2
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-3
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-4
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-5
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-6
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-7
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-8
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-9
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE