Hard start
09-06-2018, 07:16 PM
#1
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Hard start
Hello, I’m new to this site and I need a little help. I have a 99 c5 and I just replace the fuel pump, fuel filter and fuel pressure regulator on the fuel rail because a repair shop said my fuel pressure would drop when the key was turned off making it hard to start. The people who installed the pump said it’s holding fuel pressure at 50 but I still have the same problem( long cranks).They said I need to take to dealer to have it checked out because they didn’t have the proper tool for diagnosing it. I appreciate any help you can give me or point me in the right direction. Thanks again
09-06-2018, 07:52 PM
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St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16-'17
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Next question....what brand of fuel filter? Our cars don't like aftermarket filters sometimes.
09-06-2018, 07:54 PM
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St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16-'17
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Also....just a quick search brought up this...
https://www.corvetteforum.com/forums...r-ign-off.html
https://www.corvetteforum.com/forums...r-ign-off.html
09-06-2018, 07:55 PM
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09-06-2018, 08:45 PM
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I was going to get one from Napa but for some reason I didn’t. Will a bad fuel filter from advanced make the car crank longer to start even tho the fuel pressure is holding at 50 ?
09-06-2018, 08:49 PM
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09-07-2018, 01:19 AM
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09-07-2018, 07:49 AM
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Hey there !!
The fuel pressure should not drop when the key is turned off after the 2 second prime. Should NOT drop more than 5 psi after 1 minute. You most "likely" have a leaking fuel injector. That is why the car is hard to start. The repair shop had the right tool initially for the diagnosis...a fuel pressure gauge !!!...find yourself another shop...INCOMPETANT !!
The fuel pressure should not drop when the key is turned off after the 2 second prime. Should NOT drop more than 5 psi after 1 minute. You most "likely" have a leaking fuel injector. That is why the car is hard to start. The repair shop had the right tool initially for the diagnosis...a fuel pressure gauge !!!...find yourself another shop...INCOMPETANT !!
09-07-2018, 09:31 AM
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Hey there !!
The fuel pressure should not drop when the key is turned off after the 2 second prime. Should NOT drop more than 5 psi after 1 minute. You most "likely" have a leaking fuel injector. That is why the car is hard to start. The repair shop had the right tool initially for the diagnosis...a fuel pressure gauge !!!...find yourself another shop...INCOMPETANT !!
The fuel pressure should not drop when the key is turned off after the 2 second prime. Should NOT drop more than 5 psi after 1 minute. You most "likely" have a leaking fuel injector. That is why the car is hard to start. The repair shop had the right tool initially for the diagnosis...a fuel pressure gauge !!!...find yourself another shop...INCOMPETANT !!
09-07-2018, 10:20 AM
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They did have a pressure gauge and with engine turned off the pressure held at 50 without dropping.They said it could be the computer or maybe a crank sensor or something else, that’s why they said take it to a dealer which I rather not because they will charge $$$$$.
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09-07-2018, 12:13 PM
#14
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You had said in your initial post...."a repair shop said my fuel pressure would drop when the key was turned off making it hard to start."...OK, I'm assuming that was the first shop...yes, long crank times are "usually" indicative of a faulty crank sensor. A quick check you can do is while cranking look and see if you have any tach movement while trying to start the car...no tach movement, no crank sensor output !!...NOT easy of a job if you do it yourself...I'm surprised that shop told you they don't have the "right tooling" to diagnose it (a DSO)….if you are in the NY/NJ area I'd be happy to diagnose it for you...but not change it if it is the crank sensor...LOL !!!
09-07-2018, 01:01 PM
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I wish I was closer but I live in the Ocean City Md. area. I hope I didn’t confuse you, the first shop said fuel pressure was dropping when key turned off that’s why it’s hard starting. He quoted me $1800.00 (parts included) to repair car, well that was a no go so I got the parts myself. A friend told me of another shop he heard was good and fair so I decided to give them a shot. They said there was no fuel pressure when removing fuel lines then fuel pump. After they were done it still had the long crank to get started, they checked the fuel pressure and it now holding at a steady 50ps with key turned off. That’s when they told me it could be the computer, maybe crank sensor or something else and that I should take it to a dealer to have it checked out because they didn’t have the tools to do so. Thanks again for any help you can give me !
Last edited by C5 Diag; 09-07-2018 at 01:04 PM. Reason: insert pic
09-08-2018, 01:48 AM
#16
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Hello, I’m new to this site and I need a little help. I have a 99 c5 and I just replace the fuel pump, fuel filter and fuel pressure regulator on the fuel rail because a repair shop said my fuel pressure would drop when the key was turned off making it hard to start. The people who installed the pump said it’s holding fuel pressure at 50 but I still have the same problem( long cranks).They said I need to take to dealer to have it checked out because they didn’t have the proper tool for diagnosing it. I appreciate any help you can give me or point me in the right direction. Thanks again
Where is the fuel filter located on a 1999???
09-08-2018, 05:57 AM
#17
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Fuel pressure on a 99 C5 should be 58psi not 50psi and the filter and pressure regulator should not be on the rail. The pressure regulator is part of the fuel filter. As mentioned make sure you have the correct filter installed correctly.Under the car, drivers side frame rail, outboard of the transmission ( between the trans and the frame rail)
Where is the fuel filter located on a 1999???
09-08-2018, 10:32 AM
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As BigGun had mentioned F/P should be 58 psi on a '99...I didn't even pick up at that number...DUH !!...my '01 is 55-62 (non supercharged) and 50-62 (supercharged).Ok, we have a new pump and is it an aftermarket or OEM ??...something like a pump I's stick to OEM...if it is a "good" pump and that's key here and we have the correct fuel filter/regulator we now have to look at power and grounds. let's see if we have a clean ground at G-401 which is the ground for the pump (rear frame rail aft of rear upper control arm). There might be high resistance on that circuit...Sir, I don't know if you do your own maintenance but you can try that. I'd ask the guys who did the pump install why you got it back with low fuel pressure...TAKE IT BACK !!...show them minimum F/P is 58 psi. might be an incorrect diagnosis...I'm not sure if 50 would cause a long crank time...20 yes, 50 maybe. If you want to try to check the current draw of the pump you can pick up one of these ammeters...they are pretty cheap and easy to use and you can at least check the pump current. Say EVERYTHING checks good...now we have to go back to the tank and start troubleshooting there. Could be a bad check valve in the fuel feed rear pipe. OUCH !!!
09-09-2018, 01:05 AM
#19
Drifting
Hi, the fuel pump, the fuel filter/regulator on the frame and the fuel injection pressure damper were replaced( sorry if I described it wrong ) I asked them to hook up the pressure gauge to make sure it was holding pressure now with the key turned off and they said it was holding at 50psi. Is that not high enough to cause long cranks to start ? Thanks again for any help you can give me
Does it read the same thing with the key on? What does it read after starting?
09-09-2018, 06:45 AM
#20
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Hi James, not sure of those readings, might take it to another shop this week and have them check out the fuel pressure. It seems that it always takes to 2 times to start. I turn key to on position, here the fuel pump kick on then off then I crank it for a second or two then turn the key back off then back on again, I hear the fuel pump kick back on and off for the second time and the it starts right up. That tells me it’s probably a fuel problem, maybe a bad or cheap aftermarket fuel pump( was told fuel pump had a reverse flow check valve built in it ) but I’m guessing the fuel system is not getting a good prime ? Thanks again !