repeat question

[dsadams]

As I've seen on here this will be a repetitive question or statement. My 01 LS V8 cranks like mad but won't fire. I have a hard time believing that replacing the battery will cure it. I even have a batt. charger to help the voltage be higher with no sucess. I only took the batt. terminals off to clean and reinstall. No big deal - so I thought . Anyway, hopefully someone can point me in the right direction.

[shorod]

Are you saying that the car started fine, then you took the battery cables off to clean them and now it won't start?

Did you do any maintenance under the hood, such as checking the air filter, etc.? If so, maybe you left the MAF sensor unplugged or didn't get the air intake hose on tightly.

If the only thing you did was battery cables, then find a multimeter and a friend to watch the battery voltage while cranking the engine. If it's anything lower than 10.5 Vdc when cranking, the problem is likely the voltage.

If the voltage is good, you will need to check to see if you have fuel to the cylinders. Pull a spark plug or two after cranking and see if it/they are moist with fuel.

-Rod

[dsadams]

Thanks for the response. Unfortunately however, I did not do anything under the hood. I'll keep trying!

[Towncar]

Stick to the basics:
Compression, Fuel, Spark. With all three you have a running engine. Now your task is to find out which one(s) are missing.

We can only get into the "why" after your tell us "what" is missing.

[dsadams]

O.k. I feel that you guys should know - it was a fuse for the fuel injection, located in the fusebox under the hood. Somehow, someway, I guess the voltage spike or some other strange cosmic event occurred and left me with this condition! Anyway, problem is solved and I am back on the road. Much thanks to all that replied!

[shorod]

Thank you for the follow up. This could help others in the future.

I'll try to make some time to check the factory diagrams for the fuel injector circuit. I'm curious what may have caused the fuse to blow. I would not expect removing and reinstalling battery cables to cause the fuse to blow.

-Rod

[Towncar]

Originally Posted by dsadams

O.k. I feel that you guys should know - it was a fuse for the fuel injection, located in the fusebox under the hood. Somehow, someway, I guess the voltage spike or some other strange cosmic event occurred and left me with this condition! Anyway, problem is solved and I am back on the road. Much thanks to all that replied!

Excellent !!!

Thanks for the followup

[shorod]

Was the blown fuse the 20A fuse or the 40A fuse in the Auxilliary Junction Box under the hood? The 40A fuse supplies power to the PCM relay, and the output of that relay supplies the 20A circuit which provides B+ power to the fuel injectors. The injectors are switched on and off by the PCM controlling the ground side of the injectors. The injectors appear to be the only items on the 20A circuit.

-Rod

[dsadams]

It was the 20a fuse only. Strangest thing I've seen in a while!!

[shorod]

If the fuse blows again, or if you get bored some weekend, you may want to unplug the injectors and measure the coil resistances of them them, see if any are out of tolerance. If not, inspect the wiring for them for damage. I would expect the the driver transistors in the PCM have a current-limiting resistor in series with them to prevent a dead short (either in wiring or injector coil) from burning up the transistor. I agree, this one is a strange one. Hopefully you won't have any future problems with it.

-Rod