Injectors not firing
Veteran Member
Joined: Aug 2021
Posts: 4,674
Likes: 1,323
From: Kansas City
Cleaned the faces of the 2 crankshaft position sensors ? different then connector clean
There should be 2 crankshaft position sensors fwd and aft face of the block
Does the V - 12 have a camshaft position sensor only used in the starting sequence ?
swapped the fuel pump relay , # 2 may still be OK not being used in the starting sequence
Cylinders put into a bore wash condition ?
Using old fuel ?
Main fuel line filter change , flow arrow points car's outboard ?
Cleaned plugs ?
Swapped the right heelboard fuse box small king relay in the corner ? power to control the 2 fuel relays ? may explain your intermitent fuel pressure
You can jumper this relay between socket 3 to 5
inspected the # 1 fuel pump on the pump motor connector for burnt / arcing sockets ? happens as the old pump dies
pic coming , same as above pic standard relay and numbering socket
There should be 2 crankshaft position sensors fwd and aft face of the block
Does the V - 12 have a camshaft position sensor only used in the starting sequence ?
swapped the fuel pump relay , # 2 may still be OK not being used in the starting sequence
Cylinders put into a bore wash condition ?
Using old fuel ?
Main fuel line filter change , flow arrow points car's outboard ?
Cleaned plugs ?
Swapped the right heelboard fuse box small king relay in the corner ? power to control the 2 fuel relays ? may explain your intermitent fuel pressure
You can jumper this relay between socket 3 to 5
inspected the # 1 fuel pump on the pump motor connector for burnt / arcing sockets ? happens as the old pump dies
pic coming , same as above pic standard relay and numbering socket
Last edited by Parker 7; Dec 1, 2025 at 07:21 PM.
Senior Member
Joined: Aug 2020
Posts: 458
Likes: 279
From: Portland, OR
The camshaft position sensor (CMP) (14) provides one signal every 720$ of crankshaft rota-
tion indicating No. 1A cylinder at TDC prior to the firing stroke. These signals are used by the ECM to control fuel injec-
tion and ignition duration and synchronization.
tion indicating No. 1A cylinder at TDC prior to the firing stroke. These signals are used by the ECM to control fuel injec-
tion and ignition duration and synchronization.
Last edited by 944play; Dec 1, 2025 at 09:22 PM.
Senior Member
Joined: Oct 2013
Posts: 593
Likes: 510
From: Twin Waters, Sunshine Coast, QLD. Australia.
The CMP is there during cranking to determine whether the 1A piston is coming up to TDC on the compression stroke or the exhaust stroke. If the CMP is faulty the ECU makes a guess and if the engine doesn't start then the ECU tries again one rev later.
I unplugged mine to see what happened and the engine started OK but cranked a little longer before it fired up.
The CMP also is there for semi sequential fuel injection control..
I have attached some relevant info.
Cheers,
Jeff.
I unplugged mine to see what happened and the engine started OK but cranked a little longer before it fired up.
The CMP also is there for semi sequential fuel injection control..
I have attached some relevant info.
Cheers,
Jeff.
Thread Starter
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Senior Member
Joined: Mar 2019
Posts: 160
Likes: 29
Cleaned the faces of the 2 crankshaft position sensors ? different then connector clean
There should be 2 crankshaft position sensors fwd and aft face of the block
Does the V - 12 have a camshaft position sensor only used in the starting sequence ?
swapped the fuel pump relay , # 2 may still be OK not being used in the starting sequence
Cylinders put into a bore wash condition ?
Using old fuel ?
Main fuel line filter change , flow arrow points car's outboard ?
Cleaned plugs ?
Swapped the right heelboard fuse box small king relay in the corner ? power to control the 2 fuel relays ? may explain your intermitent fuel pressure
You can jumper this relay between socket 3 to 5
inspected the # 1 fuel pump on the pump motor connector for burnt / arcing sockets ? happens as the old pump dies
pic coming , same as above pic standard relay and numbering socket
There should be 2 crankshaft position sensors fwd and aft face of the block
Does the V - 12 have a camshaft position sensor only used in the starting sequence ?
swapped the fuel pump relay , # 2 may still be OK not being used in the starting sequence
Cylinders put into a bore wash condition ?
Using old fuel ?
Main fuel line filter change , flow arrow points car's outboard ?
Cleaned plugs ?
Swapped the right heelboard fuse box small king relay in the corner ? power to control the 2 fuel relays ? may explain your intermitent fuel pressure
You can jumper this relay between socket 3 to 5
inspected the # 1 fuel pump on the pump motor connector for burnt / arcing sockets ? happens as the old pump dies
pic coming , same as above pic standard relay and numbering socket
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