Start up issue, need diagnosis help from a smart mechanical guy !!
Thread Starter
Burning Brakes
Joined: Dec 2011
Posts: 858
Likes: 75
From: Medford, Oregon
Start up issue, need diagnosis help from a smart mechanical guy !!
Hey guys, yesterday my 99' C5 FRC just started to exhibit a strange symptom upon start up. Normally when starting the car, it fires right up when it starts to crank and engine fires right up, but as of yesterday, I got in to start it and it took several(6-10) revolutions) and when it did fire up and run, it was like the opposite sensation of running out of gas, it was as if the motor was starving for gas to start up and finally, slowly getting some, and this lazy start up now occurs all the time. Am I leaning towards the right direction of a possible plugged fuel filter or a possible failing fuel pump, what is pump pressure supposed to be. Has anyone shared this same symptom or problem on their cars, and if so, what was your remedy or fix. Any supportive suggestions are appreciated. 
Last edited by 2FAS4UU; Oct 16, 2015 at 04:10 PM.
Le Mans Master
Joined: Jan 2009
Posts: 6,226
Likes: 33
From: Morton illinois
St. Jude Donor '14-'15
i would guess fuel pump. when you turn the key to AC the pres should be 40-+, then slowly bleed off. when running it should be 50ish i believe. put a gauge on there. easy check to rule it out
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
My 1st guess would be an old dirty fuel filter that needs to be changed out
2nd---If you car has any sort of cold air intake that is of the oiled variety --a common issue is that the oil from the filter after a cleaning and re-oiling has fouled your mass air flow meter- This makes your start up fueling go way off as upon start up while cold and in open loop the ECM will use the last fuel trims the ECM saw when the engine was turned OFF---So if your MAF is fouled then all your cranking fuel will be off too
There could be other issues that are not so common like a massive vacuum leak or a loose clamp or hose anywhere in your intake tract--
2nd---If you car has any sort of cold air intake that is of the oiled variety --a common issue is that the oil from the filter after a cleaning and re-oiling has fouled your mass air flow meter- This makes your start up fueling go way off as upon start up while cold and in open loop the ECM will use the last fuel trims the ECM saw when the engine was turned OFF---So if your MAF is fouled then all your cranking fuel will be off too
There could be other issues that are not so common like a massive vacuum leak or a loose clamp or hose anywhere in your intake tract--
Instructor
Joined: Nov 2013
Posts: 229
Likes: 13
From: Columbia South Carolina
Go buy a new filter/regulator assembly. If you want to save some coin, the WIX brand is the cheapest, part numbers and what you will need below.
WIX 33737
NAPA GOLD FIL 3737 (Made by WIX)
ACDELCO GF822 #10299146, 19239926
Fuel line disconnect tool BK 7769085
http://www.napaonline.com/Catalog/Ca...737_0478031441
http://www.napaonline.com/Catalog/Ca...085_0494116065
Go ahead and replace that, even if that doesn't fix it you would have wanted to put on a new one with a new pump anyway, might as well start with the cheaper of the two
WIX 33737
NAPA GOLD FIL 3737 (Made by WIX)
ACDELCO GF822 #10299146, 19239926
Fuel line disconnect tool BK 7769085
http://www.napaonline.com/Catalog/Ca...737_0478031441
http://www.napaonline.com/Catalog/Ca...085_0494116065
Go ahead and replace that, even if that doesn't fix it you would have wanted to put on a new one with a new pump anyway, might as well start with the cheaper of the two
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
While you are checking fuel pressure, make sure that the pressure doesn't bleed off when you turn the ignition off.
There is a check valve in the fuel line near the tank that could be bad allowing the fuel in the lines to leak back into the tank.
When you attempt to use the release tool to remove the fuel line from the filter. the following steps will significantly help make the process EASIER!
1. Make sure that all the pressure is released from the line.
2. Before you insert the release tool into the filter; Press the filter ON TO THE LINE. This releases the pressure off the little retainer fingers inside the flange and allows the release tool to push the fingers out easier. While pressing IN on the filter, insert the release tool. Once its installed as deep as it will go, attempt to pull the filter off the line.
3. If you have issues getting the filter off, BE CAREFUL!! The line is hard plastic and will SNAP OFF if you use too much force and anger.
Bill
There is a check valve in the fuel line near the tank that could be bad allowing the fuel in the lines to leak back into the tank.
When you attempt to use the release tool to remove the fuel line from the filter. the following steps will significantly help make the process EASIER!
1. Make sure that all the pressure is released from the line.
2. Before you insert the release tool into the filter; Press the filter ON TO THE LINE. This releases the pressure off the little retainer fingers inside the flange and allows the release tool to push the fingers out easier. While pressing IN on the filter, insert the release tool. Once its installed as deep as it will go, attempt to pull the filter off the line.
3. If you have issues getting the filter off, BE CAREFUL!! The line is hard plastic and will SNAP OFF if you use too much force and anger.
Bill
Last edited by Bill Curlee; Oct 18, 2015 at 10:38 AM.
