Generation III External Engine LS1 | LS6 | Bolt-Ons | Intakes | Exhaust | Ignition | Accessories
Sponsored by:
Sponsored by:

Why won't my car start on the first try anymore?

Thread Tools
 
Search this Thread
 
Old Apr 15, 2017 | 07:41 AM
  #21  
simple's Avatar
TECH Apprentice
iTrader: (8)
 
Joined: Mar 2004
Posts: 366
Likes: 0
From: N. IL
Default

Originally Posted by HardyKefes
I have similar problem and need help: Yukon Denali 2004 fuel pressure is immediately on 60 psi, after 2 or 3 seconds I hear a click, a relay de-energizes and the pressure drops immidiately to 0. Any idea please? It seems fuel pump is creating pressure just fine. As soon as I re-turn ignition key (not starting), relay comes on, pressure is immediately back to 60 psi, after 2 to 3 sec same thing, drops to 0 immediately.
Potentially a bad fuel pump. System shouldn't bleed off pressure like that and when it does, the majority of the time it's the fuel pump that is faulty.
Reply
Old Apr 15, 2017 | 08:07 AM
  #22  
kpeters59's Avatar
Launching!
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Nov 2010
Posts: 250
Likes: 0
From: Houston, Texas
Default

Originally Posted by slayer1234
hey whats up i just recently bought a 97 LT1 with 156000 miles and same **** has been happening it wont crank the first try i checked the pressure changed out the pressure regulator but didnt help the psi goes to about 45 and then slowly drops down.. it takes about 5 secs to start up and ideas what it might be??? fuel pump??
Originally Posted by HardyKefes
I have similar problem and need help: Yukon Denali 2004 fuel pressure is immediately on 60 psi, after 2 or 3 seconds I hear a click, a relay de-energizes and the pressure drops immidiately to 0. Any idea please? It seems fuel pump is creating pressure just fine. As soon as I re-turn ignition key (not starting), relay comes on, pressure is immediately back to 60 psi, after 2 to 3 sec same thing, drops to 0 immediately.
My '06 5.3 in my '96 OBS does this kind of stuff about once a year. I usually just take my spare Fuel Injectors to the fuel injector cleaning store and then swap them out. Clears it right up...for about another year...

-KP
Reply
Old Apr 15, 2017 | 10:53 AM
  #23  
chrysler kid's Avatar
TECH Addict
20 Year Member
Photogenic
Liked
Loved
iTrader: (14)
 
Joined: Feb 2005
Posts: 2,720
Likes: 6
From: Mckinney Plano Frisco
Default

On the Yukon and trucks with the 5.3 the harness connector to the fuel pump can go bad, gets really cracked and corroded. New fuel pumps come with a new harness because the harness failing can cause the pump to fail
Reply
Old Apr 17, 2017 | 11:08 PM
  #24  
taman86's Avatar
TECH Enthusiast
15 Year Member
iTrader: (19)
 
Joined: Aug 2008
Posts: 533
Likes: 1
From: South East AZ
Default

ok guys, if your vehicle does not start up the first time then its 95% percent of the time a bad fuel pressure regulator. the earlier years and a return style system and the regulator was on the rail. later years with a returnless style system the pump acts as the regulator.

to diagnose have somebody turn the car on and just before the fuel pump kicks off with the key in the run position use a pair of vice grips and pinch the fuel line shut. if the pressure holds at that point then the injectors are good and are not bleeding off. once you release the vice grip and the pressure bleeds off then its the regulator and in some cases the fuel pump. i had this issue with my car with the later returnless style system and turned out to be the fuel pump. replaced with new walbro 255lph with new harness and fixed.

starts up the first time, every time.

also if you get the oem replacement pump kit, they do typically come with a new harness to fix the crappy original design that was causing the pumps to fail prematurely.

hope this helps, happy wrenching
Reply
Old Apr 18, 2017 | 12:05 PM
  #25  
chrysler kid's Avatar
TECH Addict
20 Year Member
Photogenic
Liked
Loved
iTrader: (14)
 
Joined: Feb 2005
Posts: 2,720
Likes: 6
From: Mckinney Plano Frisco
Default

Originally Posted by taman86
ok guys, if your vehicle does not start up the first time then its 95% percent of the time a bad fuel pressure regulator. the earlier years and a return style system and the regulator was on the rail. later years with a returnless style system the pump acts as the regulator.

to diagnose have somebody turn the car on and just before the fuel pump kicks off with the key in the run position use a pair of vice grips and pinch the fuel line shut. if the pressure holds at that point then the injectors are good and are not bleeding off. once you release the vice grip and the pressure bleeds off then its the regulator and in some cases the fuel pump. i had this issue with my car with the later returnless style system and turned out to be the fuel pump. replaced with new walbro 255lph with new harness and fixed.

starts up the first time, every time.

also if you get the oem replacement pump kit, they do typically come with a new harness to fix the crappy original design that was causing the pumps to fail prematurely.

hope this helps, happy wrenching
98% of the time slow start or cranking and starting second try is the ignition relay being worn.

I've only heard rumors of very early 98 models having the fpr on the rail, but I've never seen one. It would also mean there would be two pump part numbers for 98 models, but there are not. I believe a preproduction 98 fbody was used for testing for a few vendors which had an fpr on the drivers side rail, but again I've never seen one. I've had quite a few 98's, and I can remember seeing a few x code vin 97 trans ams on ebay a few years back. (Mostly incomplete vehicles, but they were listed as registerable and street legal)

I had a typhoon intake a loong time ago and it said 98's needed special adapters but mine did not.

So I believe the fpr on the rail for 98 models is a myth
Reply




All times are GMT -5. The time now is 04:36 AM.

story-0
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-1
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-2
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-3
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-4
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-5
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-6
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-7
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-8
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-9
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE