Awesome. Thanks. Going thru them now..

 

I cleared the codes... did a fuel pressure test while running. The random misfire and cyl #5 misfire came back while I was running the fuel test. The whole time I had a steady 42-44psi fuel pressure. Fuel pump is okay then I guess?

 

Was doing more research... Came across this

"A bad crank position sensor can worsen the way the engine idles, the pistons fire, or the acceleration behavior. If the engine is revved up with a bad or faulty sensor, it may cause misfiring, motor vibration or backfires. Accelerating might be hesitant, and abnormal shaking during engine idle might occur. In the worst case the car may not start."

Sounds almost exactly like what I'm experiencing... any thoughts on testing this?

 

Crank sensor is one that the ECU has no back up plan for. Erratic ones typically cause stall when hot, and no re-crank until cooled off. But they can make strange things happen, and do fail. Guys carry a spare one when going way off the beaten path.

The unit is a reluctor pickup sort of device, the nose of it is like 2 mm away from the slotted ring you see on the front of the flywheel (not the teeth that the starter engages). Those notches are 6 degrees apart, and there is a gap that indicates position to the ECU. Metal trash on the nose of the sensor could be an issue as well. They're like $70 -90, a PITA to install, plug in and let hang down before mounting. Spacers have to go in as shown, so nose is a precise distance from the internl disc.

And there are pages about that timing in the Bosch manual I sent you. The pages from the RAVE show a voltage chart vs RPM, so that could be monitored, but of course the unit needs to stay plugged in or truck won't run. The norm for yes/no is when truck dies and won't recrank: pour cold water on it, or spray with brake cleaner (cools off).

 

GA Rovee, did you find what the problem was?

 

Hi I have a 1999 Land Rover Discovery SD (1) I'm pulling code p0451 which has something to do with fuel tank pressure and im also getting p0300 which means random misfire. I changed two coils, plugs, cleaned MAF and changed a busted O2 sensor. What should I do?

 

you should start your own post piggy backing on a 2-year old post may not get you far.

 

Yes your absolutely right but to be perfectly honest I don't know how to start my own post. Could you teach me?

 

Good day sir. I have same problem with my 06 sport supercharge. I have change spark plugs, coils, o2 sensors, catalytic converter. but still same problem. Pls did u fine out what's was the problem?

 

Good day sir. I have same problem with my 06 sport supercharge. I have change park plugs, coils, o2 sensors, catalytic converter. but still same problem. Pls did u fine out what's was the problem? I have put more than $3000 but still same problem. random misfire and pawer dropping out.

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