Hard Starting 2004 Z06
Thread Starter
Advanced
Joined: Mar 2013
Posts: 90
Likes: 1
From: Mission Viejo CA
Hard Starting 2004 Z06
Hi all!
This is my first post on here regarding my new-to-me 04 Z16 Z06. It has 30,000 miles on it and is in great shape.
The only thing that I have noticed is that it takes about 5-6 seconds of cranking before the car fires and starts.
This only occurs in the morning, when the car hasn't been driven for 10-12 hours. During the rest of the day it starts after about 1-2 seconds of cranking.
I have tried priming the fuel system by turning the key to "ON" but not starting it, several times. This seems help with the problem.
Before buying this Vette, I had a LS1 Camaro for 9 years, so I am pretty familiar with GM's F-body platform and the LS1/LS6.
I guess the question is, why do I have to prime my Vette when my Camaro LS1 would start on the first crank and the Vette starts fine during the day?
Is there a leak in the top end of the fuel system that is allowing air in while the car sits over night?
Thanks
PS I have not pulled codes yet, but will try and do that when I get home tonight.
This is my first post on here regarding my new-to-me 04 Z16 Z06. It has 30,000 miles on it and is in great shape.
The only thing that I have noticed is that it takes about 5-6 seconds of cranking before the car fires and starts.
This only occurs in the morning, when the car hasn't been driven for 10-12 hours. During the rest of the day it starts after about 1-2 seconds of cranking.
I have tried priming the fuel system by turning the key to "ON" but not starting it, several times. This seems help with the problem.
Before buying this Vette, I had a LS1 Camaro for 9 years, so I am pretty familiar with GM's F-body platform and the LS1/LS6.
I guess the question is, why do I have to prime my Vette when my Camaro LS1 would start on the first crank and the Vette starts fine during the day?
Is there a leak in the top end of the fuel system that is allowing air in while the car sits over night?
Thanks
PS I have not pulled codes yet, but will try and do that when I get home tonight.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
There is a very small fuel line check valve inside the fuel line near the tank. They have been known to go bad and allow all the fuel in the line to drain back to the tank thus causing LONG CRANK TIMES. The fuel pressure gage will tell you good solid info but, even though you see PRESURE at the gage, make sure that its not pressurized AIR in the line.
If you press the shrader valve on the front of the driver side fuel rail, you should immediatel see presurized fuel.
YOU ARE CORRECT. Your car should fire right off without extended crank times.
If you press the shrader valve on the front of the driver side fuel rail, you should immediatel see presurized fuel.
YOU ARE CORRECT. Your car should fire right off without extended crank times.
Thread Starter
Advanced
Joined: Mar 2013
Posts: 90
Likes: 1
From: Mission Viejo CA
There is a very small fuel line check valve inside the fuel line near the tank. They have been known to go bad and allow all the fuel in the line to drain back to the tank thus causing LONG CRANK TIMES. The fuel pressure gage will tell you good solid info but, even though you see PRESURE at the gage, make sure that its not pressurized AIR in the line.
If you press the shrader valve on the front of the driver side fuel rail, you should immediatel see presurized fuel.
YOU ARE CORRECT. Your car should fire right off without extended crank times.
If you press the shrader valve on the front of the driver side fuel rail, you should immediatel see presurized fuel.
YOU ARE CORRECT. Your car should fire right off without extended crank times.
Can I replace just the valve by uhooking the fuel line at the tank, or do you think this will require a whole new fuel line?
Maybe some Techron?
Thread Starter
Advanced
Joined: Mar 2013
Posts: 90
Likes: 1
From: Mission Viejo CA
This may be correct for the NON-FFS fuel system. However the OP says he has a 2004 Z06 so he has an FFS Fuel System.
The check valve is a part of the pump assembly in the tank. Part W in the following link/diagram.
http://xlr-net.com/kb/questions/44/
If the check valve is failing then repair is NOT a simple procedure as the pump assembly cannot be removed on the FFS sysem without dropping the left side tank.
Before I went to the trouble of dropping the tank I would exhaust all other possibilities. JMHO.
The check valve is a part of the pump assembly in the tank. Part W in the following link/diagram.
http://xlr-net.com/kb/questions/44/
If the check valve is failing then repair is NOT a simple procedure as the pump assembly cannot be removed on the FFS sysem without dropping the left side tank.
Before I went to the trouble of dropping the tank I would exhaust all other possibilities. JMHO.
What other options might you look at? Check all of the fittings to make sure there are no leaks allowing the fuel to drain back?
I think if it was the check valve, it would still be hard to start in the middle of the day...
Thread Starter
Advanced
Joined: Mar 2013
Posts: 90
Likes: 1
From: Mission Viejo CA
Certainly checking all the connection points would be a step(s). Some under the car at or near the tanks are going to be difficult to get to but there may be fuel stains if you can get the car on a lift to check. It could be one or more injectors that are leaking down as well. Check the dipstick and see if the oil has a strong fuel smell. Do you have any cloud that eminates from the exhaust when you start it in the morning (cold)? What color if there is a cloud?
How else would I check for a leaky injector other than taking them out and having them tested?
The dipstick doesn't smell strongly of fuel.
Now I am worried about a washed down cylinder
Thread Starter
Advanced
Joined: Mar 2013
Posts: 90
Likes: 1
From: Mission Viejo CA
Alright, I went and pulled the codes from my IPC and this is what I got (all of them)...is there a thread/website that shows all of the codes for a 2004? I tried searching with no luck...maybe you can decode them 8VETTE7.
B0367H
B2283H
B2287H
B2285H
B2282H
B2286H
B2284H
U1064H
U1096H
I think the U1064 and U1096 have something to do with a ground on the bottom of the block, but it seems from another post that it is inaccessible.
Also, I think the B0367 has something to do with realigning my actuators in the HVAC system...
Thanks again guys!
PS I have owned the car for about 2 months, so I have cycled the ignition at least 50 times and the codes still show as "H", which tells me these have happened recently...
B0367H
B2283H
B2287H
B2285H
B2282H
B2286H
B2284H
U1064H
U1096H
I think the U1064 and U1096 have something to do with a ground on the bottom of the block, but it seems from another post that it is inaccessible.
Also, I think the B0367 has something to do with realigning my actuators in the HVAC system...
Thanks again guys!
PS I have owned the car for about 2 months, so I have cycled the ignition at least 50 times and the codes still show as "H", which tells me these have happened recently...
Last edited by gun5l1ng3r; May 3, 2013 at 09:48 PM. Reason: Added info
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Corvette & Porsche 911: How Two Icons Conquered the Last 25 Years
Joe Kucinski
2027 Chevrolet Silverado 1500 First Look: Everything You NEED to Know!
Michael S. Palmer
5 Best & 5 Worst Corvette Daily Drivers
Joe Kucinski
The Headlights of Every Corvette Generation Explained
Joe Kucinski
5 Best & 5 Most Overrated Corvette Track Packages of All Time!
Joe Kucinski
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
Thread Starter
Advanced
Joined: Mar 2013
Posts: 90
Likes: 1
From: Mission Viejo CA
Actually I have to get my car smogged here in California in the next couple days...
I will wait until afterwards to reset the codes. Why shouldn't I clear the codes before a smog test?
I will wait until afterwards to reset the codes. Why shouldn't I clear the codes before a smog test?
Thread Starter
Advanced
Joined: Mar 2013
Posts: 90
Likes: 1
From: Mission Viejo CA
Now I just have to perfect my Vette Wave
Melting Slicks
Joined: Dec 2003
Posts: 2,334
Likes: 11
From: las vegas nv.
There is a very small fuel line check valve inside the fuel line near the tank. They have been known to go bad and allow all the fuel in the line to drain back to the tank thus causing LONG CRANK TIMES. The fuel pressure gage will tell you good solid info but, even though you see PRESURE at the gage, make sure that its not pressurized AIR in the line.
If you press the shrader valve on the front of the driver side fuel rail, you should immediatel see presurized fuel.
YOU ARE CORRECT. Your car should fire right off without extended crank times.
If you press the shrader valve on the front of the driver side fuel rail, you should immediatel see presurized fuel.
YOU ARE CORRECT. Your car should fire right off without extended crank times.
Melting Slicks
Joined: Dec 2003
Posts: 2,334
Likes: 11
From: las vegas nv.
You don't--that line blocks some fuel from going to the tank and is always under pressure--so when you start when cold the fuel is there-for a quick fire up--goes from the fuel filter to one of the tank pumps--I think you need a pro to do it--BTW the line is like 150.00 if I remember right some years ago-that I think is your problem