Help with an interceptor 4.6 please

[uglyII]

Hey guys,
Not a 4.6 owner myself, but looking for some help with my buddies 4.6. The vehicle is a '96 police interceptor with 80k miles. He bought it knowing the engine does not run, and now we are trying to work through what might be the issue. So far we know it definitly has:

-Air
-Spark
-Camshaft rotation, though I cant confirm timing is correct yet.
-Good fuel pump, can smell gas after trying to start

The engine will turn over freely, but it doesn't sound like combustion is occuring in any of the cylinders. However, it will backfire out the throttle body.

What would you guys be checking first?

 

[Dragstr05]

If its backfiring, then you know its firing, just maybe not at the right time. Possibility the timing chain jumped a tooth or two and the timing is off, but I cant say how much the timing would have to be off for it not to run.

Do you have any way of verifying that your crank/cam sensors are operating correctly?

 

[blacksheep-1]

Of course you mean the mustang that someone swapped a 96 interceptor into, right?...wink, wink, nod nod

 

[Spiggs]

Sounds like a timing issue. Put #1 on TDC and check the cam timing from there.

 

[Mel96GT]

Do a compression test. Both banks should be within 10% of each other. If you spot a weak cylinder, drop a bit of oil (to temporarily seal the rings) and then re-check compression. If the compression goes up; bad rings. You could also have a burnt valve so if the oil trick doesn't work, it could be the valves. Also, if one bank is higher than the other's compression, then the lower compression bank may have a missed tooth on the cam gears. Also, make sure your cam sensors are working. RE-CHECK your firing order!! Good luck.

 

[venom5sc]

Since there is already conversation about it, are there any advantages to the interceptor engines? Police cars used to have the better parts on them but is this the case in any way when compairing a crown vic to a mustang?

 

[Dragstr05]

Since there is already conversation about it, are there any advantages to the interceptor engines? Police cars used to have the better parts on them but is this the case in any way when compairing a crown vic to a mustang?

If either has an advantage it'd be to the mustang. I'd imagine the mustang 4.6 has a more aggressive cam profile than the intercepter.

 

[bdcardinal]

they have the same cams. the motor from the oil pan to the lower intake is the same. the crown vic has the upper plenum pointed the other way.

 

[brent_cosenza]

if its doing this------- http://youtube.com/watch?v=rGXzfYJ0gBg

it needs a valve job pull the heads off and take em to a machine shop...