StevieZ

iTrader: (3)

I was moderately accelerating in 4th when the engine started backfiring badly and and shut down. Felt like the time I broke my timing chain in my 1970 GTO. I coasted to a stop and tried cranking it and it would just fire and backfire couple of times. Then it stopped turning over all together. I read the codes and bseides P0300 misfire one was C0336 Crankshaft position performance range .Would a busted timing chain throw this code? I got the car to turn over again but all it does it fire a couple of cylinders and back fire.
Any educated guesses? The chain is a double rollmaster.

PREDATOR-Z

Could be chain or could be bad crank positioning sensor, worst case reluctor wheel

StevieZ

iTrader: (3)

OK ... The chain isn't broken. There's no movement or play on the reluctor wheel (Lunati crank) and the sensor was clean so how do I check if it is the wire or the sensor itself? Where and what do I measure? ie: which pins on the plug and what should the voltage be? Would a sensor give out with with no prior signs? The car was running fine and then shut down like a plug was pulled.

Billy177

try tapping the crank sensor with something, a lot of times you can get parts to start working temporarily

StevieZ

iTrader: (3)

I replaced the sensor and it still doesn't start. I am going to try to test the wires.

StevieZ

iTrader: (3)

I tested the wires from the plug to about 5" from the ECM and they test good. Can anyone give suggestions as to what it might be?

JakeY2KZ

iTrader: (9)

Broken valve spring? Pull your covers and check. Similar situation happened with one of my friends car.

Billy177

do you have fuel pressure?

delsold

iTrader: (7)

+1 thats what i was thinking

StevieZ

iTrader: (3)

My fuel pressure is good but I don't seem to have spark. I used one of those testers that is supposed to light up but no light! What can it be?

Billy177

check the wiring to the crank sensor, there is the small possibility though you got a defective one.

StevieZ

iTrader: (3)

I checked them from about 5" from the ECM down to the plug and they tested good. Do you think it could be the connection at the module? Or better yet the module itself?

StevieZ

iTrader: (3)

I plan on checking all the grounds tomorrow but short of that does anyone else have any suggestions?

doaberetta

iTrader: (1)

I'm having the same issue with my lt1....
Replacing sensor tomorrow... Keep me posted aswell.

Specialized

iTrader: (15)

Crank sensor. Change it and you'll be golden.

Horsepwraddict

iTrader: (12)

Cam sensor? could do it

Thule

i got this backfire problem to

Phoenix 5.7

iTrader: (7)

spark won't fire without a good crank signal.

StevieZ

iTrader: (3)

Well this is an old thread at this point but to bring you up to date, I took out the motor and took it right down. The reluctor wheel got damaged by a piece of an inner valve spring (crane) that made its way down threw the pushrod hole. It had been floating around the bottom end for a YEAR!! Who knew? It finally got caught between the back of the block and the reluctor wheel taking out several teeth. Nothing else got hurt.

PREDATOR-Z

Bingo, do I get a prize??