My wife's daily driver is a 2000 XLT with 4.0 SOHC/Auto. No mods.

Thursday night while coming to stop in a parking lot the truck all of a sudden died. It was running fine and gave no warnings.

I have been working on it since then, along with a few buddies. There is no Check Engine Light on. I have tried scanning it for codes and have not come up with any. I did pick up a different scanner that I will try tonight-this one should show more than just codes for the emissions system associated with a CEL.

We have spark-plugs and wires have less than 1k miles and a brand new coilpack. While grounded to the block with an open plug there is a nice light show.

The original battery was tested and failed so we installed a new battery.

I know we have fuel-40 psi at the rail. Injectors are getting their signals-I them tested with Noid lights. The light was nice and consistent.

I tested the cam position sensor. We got 1.5 volt input. The sensor is working properly, we have a changes in measurements when we pass a piece of metal across it.

I haven't test the crankshaft sensor yet.

We tried to start it a few times and nothing. Cranks but won't fire.

Tried to start it with starting fluid down the throttle body and nothing.

Pulled the fuel filter and drained the tank thinking it was bad gas. So it has a new fuel filter and 15 gallons of fresh gas.

After all this I pulled the plugs to see what they looked like. They were all soaked with fluid. I dried them all off.

Here is the strange part-the middle plug on the pass. side had the electrode bent all the way down so that there is no gap anymore. The plugs and wires were installed by a local shop-I didn't have time to do it at the time. I am not sure if the garage damaged the plug when they installed it or I have some major issue with the motor.

Thats where I have left it. I am at a loss for what could be wrong at this point.

Any and all help would be appreciated.

Thanks
Pat

 

Cam chain let loose? Probably ought to pop off the left vavle cover to see if the front cam chain has tension or slack. Seems if the plug electrode was bent to zero gap when installed, you would ahve noticed it right away.

 

I agree if the plug was installed with no gap You would have felt it... Unfortunatly it does sould like the timing chain let loose. I am prety sure this motor has a front and rear timing chain.Witch would involve engine removal to repair.. a 2 dayjob for a skilled technition.I would definitly pull the valve covers and check the tention. also would do a compression test. There is a possiblilty that you may have bent a valve or 2. if the chaintentioner let loose you should still be able to rotate the motor enough to do a compression test. If you bent a valve get ready to pull the head. and send it to a machine shop and have it inspected and the valve replaced. unless you have set valves before i would suggest a machine shop.

 

Have you tried the fuel pump relay? It's a silent killer. What you're describing sounds a lot like what happened to mine. It's a $15 - $20 part, and takes seconds to replace. Good Luck!