Crank No start Typical Need Help
Senior Member
Joined: Jan 2020
Posts: 4,330
Likes: 1,090
From: utah
There's no shraeder valve on this vintage of 5 4 engine.
The fuel pressure is very easy to check with any OBD2 device that can read live data. Just looked for "fuel rail pressure" report back once you get a fuel pressure reading.
Also checking the "fuel pump duty cycle" PID can lend clues as to whether the PCM is seeing the signals from the fuel pump driver module and pressure sensor or not.
The fuel pressure is very easy to check with any OBD2 device that can read live data. Just looked for "fuel rail pressure" report back once you get a fuel pressure reading.
Also checking the "fuel pump duty cycle" PID can lend clues as to whether the PCM is seeing the signals from the fuel pump driver module and pressure sensor or not.
Last edited by needsmoarturbo; Sep 17, 2025 at 08:42 PM.
Senior Member
Joined: Apr 2023
Posts: 4,290
Likes: 1,387
From: Near Salt Lake City
[QUOTE=SimpsonB;7800832]
Sounds like to me that PATS is still the problem, and was the initial problem
Bought a 1990 Corvette from a glitter lot because they could not get it to run but it fired on ether
Got over there with a tow truck and noticed jumper cables under the car, mechanic said it wouldn't crank either and he was using them to crank the starter over
Told me he put a new fuel pump in it
So, in that case, 1 no injector pulse, 2 no crank, 3 no fuel pump = BINGO the "pass key" on that Corvette was not happy with the key code
There were at least 3 PATS systems in the early days
One system would let the car start and run, but when you put it in gear or hit the clutch it would die
Used to have fun playing with those ones when programming keys
Apparently, you DIDN'T bypass the PATS
Of course it's OBD2 being 1996 and newer
Get a good scan tool, read the codes and fuel pressure, see if it will start on ether
If it will not start on Ether, pull a plug or 3 and check for spark
Might want to check the grounds under both kick panels before you do anything[/QUOTE
The valet switch is on ive used that to bypass as its the only way I did get crank back. bypassed intertia no crank jumped with the negative to ground and still no crank until I did bypass on pats.
fuel pump hums but doesnt seem to keep kicking wondering if theres a trigger wire here or soemthing alone those lines. All grounds redone brand new starter fdpm battery cablets etc
Of course it's OBD2 being 1996 and newer
Get a good scan tool, read the codes and fuel pressure, see if it will start on ether
If it will not start on Ether, pull a plug or 3 and check for spark
Might want to check the grounds under both kick panels before you do anything[/QUOTE
The valet switch is on ive used that to bypass as its the only way I did get crank back. bypassed intertia no crank jumped with the negative to ground and still no crank until I did bypass on pats.
fuel pump hums but doesnt seem to keep kicking wondering if theres a trigger wire here or soemthing alone those lines. All grounds redone brand new starter fdpm battery cablets etc
Bought a 1990 Corvette from a glitter lot because they could not get it to run but it fired on ether
Got over there with a tow truck and noticed jumper cables under the car, mechanic said it wouldn't crank either and he was using them to crank the starter over
Told me he put a new fuel pump in it
So, in that case, 1 no injector pulse, 2 no crank, 3 no fuel pump = BINGO the "pass key" on that Corvette was not happy with the key code
There were at least 3 PATS systems in the early days
One system would let the car start and run, but when you put it in gear or hit the clutch it would die
Used to have fun playing with those ones when programming keys
2004 F150 5.4 Lariat
Joined: Dec 2012
Posts: 956
Likes: 156
From: Summerville, SC
On further research apparently needmoarturbo is right that it does not have a Shrader valve. So to check the fuel pressure you need an OBD-II reader and an app like Forscan. But you could test the fuel flow another way. You can disconnect the fuel line at the fuel filter and check the flow. You'll need a special tool (cheap) to disconnect it. If you have a hose that will fit over the filter, do that and put the other end in a container. Then turn the key to Run for ~3 seconds. Cycle the key 2-3 times (ON for 2-3 seconds. then OFF, repeating) until the quantity of fuel flow is known.