Nissan Repair: 1998 nissan maxima would not start, fuel pressure gauge, shaft sensors

Question
Rob  I my car drags when starting. I am certain i have a good battery. i clean my starter up but the dragging continues. i bought a new starter installed it but the dragging continues. it is not continuous. when i try to start the engine at first it would have the normal roll over. but if it doesn't start on that roll it immediately drags. today i changed the transmission mount but just before i did i add 4oz of mistery oil to the gas tank. after completing the mount i tried to start the car but it wouldn't. it did exactly when i describe earlier except starting. i unsrew a coil and had my son roll the engine and it was firing. i remove a spark plug and notice it was black (charred) also it appears to have gasoline in the threads. did i add 4oz of mistery oil to too little gasoline? why is the engine dragging. you recommended me to change the knock sensor but the only thing that changed was the pinging sound. this is a engine that i fixed the rear timing chain oil leak and had to remove the timing gears. i used a haynes manual and followed the timing procedures. once the engine starts it has all of its power. can the crank and or cam shaft sensors be bad. how can i get it start now. thanks in advance.

Answer
Kingsley,

Changing the knock sensor was a good thing since the engine stopped pinging.  The pinging/knocking will damage the rod bearings and eventually lead to rod bearing failure.  So, that knock sensor change was money well spent.  Nissan does not recommend fuel additives so I would suggest a tank of premium to dilute the mix.  The black plugs and gas on the threads indicates a flooding condition.  That is probably the cause of the dragging on the starter too.  If the timing gears are where they are supposed to be mechanically I would think you need to do an injector leak down test to see which injectors are leaking and to check for proper fuel pressure.  Get a fuel pressure gauge and check the pressure with the key in the on mode.  Then, turn it off and see if it holds pressure for a minute or so.  If not, you have leaky injectors.  The plugs that are really black and coated with gas are the cylinders with defective injectors.  Email me back after you check the pressure and leak down and let me know what you find.