Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
Hi my name is***** will be glad to help. Check the filter housing and bottom sensor for leaks and the lines as well for any leaks in the system. these are known for leaks at the filter housing and is likely why your pressure is bleeding off. Let me know
Thanks for the update. Do you have any fault codes logged by chance? If fuel pressure is good and no leaks the problem is likely electrical.
Does your low pressure lift pump have an internal non-return valve?
If not I would add an inline non-return valve.
How about key on and off 5 times prior to starting?
5 seconds on 5 seconds off 5 times, like after changing a fuel filter.
I feel your pain.
You say it has a new high pressure pump?
New or original control valve?
Can you tee in a fuel pressure gauge near the filter the check the supply pressure?
So somebody else has fitted a high pressure pump and injectors, has all the necessary programming been done?
Do you have a scan tool that can monitor rail pressure?
What happens to the fuel pressure gauge when you press the primer?
I don't think that 8 psi is enough.
It does sound baffling, the only thing I can now offer is a GM scan tool needs to be used, since possibly the learn functions aren't quite correct.
This is the original fault of no start unless the primer is operated?
Is the primer soft initially, and how much does it take to go hard?
And does it only take one pump on the primer, and the engine starts normally?
One more thing, perhaps the fuel tank is not venting well?
Can we take the tank cap off to see if that makes a difference?
Does it still have the intank pump?
I'll admit that I'm not familiar with yours, but it does seem similar to some of ours.
I did think some ideas may help you.
I'm sorry I was not able to help you fix this, so I'll opt now, hopefully another tech with some specific experience will be along shortly.
No need to answer back as it will bounce the question back to me.
Hope you can fix this one.
Hello and welcome to JustAnswer!
Do you still need help?
What is rail pressure while cranking when it won't start?
Let me know what you find and we'll go from there.
hello can I assist you ?
can I offer you a suggestion ? You say that the engine will always start after you pump the primer , correct ?
once it starts . it runs fine , no problems ? and will it continue to start on its own if you turn it off and attempt to start it again ?
okay so , humour me here if you can . Do you have access to compressed air ?
do you have someone there to help you ? Take an air hose with a blower nozzle , using a rag wrapped around the blower to form a " gasket " if you will . Apply a small amount of air pressure to the fuel tank at the fuel filler . With the air pressure applied ( do not apply too much , don't blow up the tank , LOL ) with the tank pressurized try to start the engine . Does it start ?
okay . just checking . May I ask ? can you try it again please ?
bear with me . when you have the chance , try it again . :-)
okay . I am happy to offer my thoughts and hope that I can help get you fixed up .