I GIVE UP, calling in the big expensive guns.

I give up. I beg for help, I'm calling a tech tomorrow to schedule a time to come to my house. I feel defeated after so many parts orders, time sweating, crushing kids hopes, bloody knuckles......you know.

I purchased a 2002 Pro Air Nautique with "A blown engine". Come to find out it was the starter seized and had the engine locked in place.

Now I can't get it to run.....at all. I get a backfire, that's it.

Things I've done:
Oil change (Engine and Transmission)
torque plate and seals
Replaced the plugs/wires/cap/rotor, yes, I checked the routing and rotation. All in place
Replaced the low pressure pump, wasn't running even after changing the relay and jumping relay.
High pressure pump runs, changed filter.
Checked pressure at fuel rail, I have pressure!
New gas
New water pump, thermostat
New raw water pump
New belts, hoses, and oil lines
Fresh battery
Checked all grounding wires, looks good.
Checked for spark, I have spark.

I'm at a loss.......All I get is great oil pressure while turning over and an occasional backfire. A backfire to the point it blew the exhaust flap off.

Any ideas?

Have you put a timing light on it ? Wait, it won’t run, forget I asked. lol

Dumb question but is the engine turning the correct direction? And you might want to check your muffler to make sure the strong backfire didn’t cause it to crack.

Orlando76 wrote: Dumb question but is the engine turning the correct direction? And you might want to check your muffler to make sure the strong backfire didn’t cause it to crack.

Yes, The engine is turning in the correct direction, I removed the cap and used the starter to check rotation in conjunction with the firing order. All is correct.

At this point, if I cracked the muffler then I will replace after it's back up and running.

Fill us in a little more please did you end up replacing the block or did you have it rebuilt? Was the distributor taken out of the block? And yes you can use a timing light put it on #1 cylinder and see if your getting spark ie the light will flash and see where it flashes on the harmonic balancer's timing marks, should be somewhere near TDC. A GT40 has to be adjusted to the proper base setting for the ECM to adjust from there, There is also a procedure to time it to base as well. If the distributor wasn't put in the proper way in the first place this very well could be your troubles.

How did you determine where to put cyl #1 (on the distributor)?

And therein lies the problem

Keep in mind that the engine will be on Top Dead Center twice in each complete cycle.
Once for exhaust stroke and once for Compression stroke. you can pull the spark plug in #1 and put your thumb or a compression tester in the hole. Now rotate your engine slowly and you will feel the compression building or see it on the gauge when you approach TDC on the compression stroke.
As you look down on the front of your engine below the distributor in your Ford you should notice one of your Heads is about 1" forward of the other head.   The First plug in this forward head is your Number 1 cylinder.   As you feel compression building start watching for your timing mark to come and align the harmonic balancer line with the TDC mark on your engine.   Top Dead Center at your Zero mark.
Once engine really is at TDC you can pull the distributor cap off and make sure your rotor inside the cap is actually pointing at the #1 plug wire on the distributor cap while you are at TDC.   If the Rotor is not at #1 you need to adjust.   At this point if you are off you have two options.   Move the Plug wires on the cap to the correct spots based on where your rotor is pointing or unbolt your distributor and lift it up to rotate the rotor to the place you want #1 to be pointing, as you drop it back down you will notice the rotor moves as it settles in, this is normal you just have to try a couple spots till you get it pointing to the spot you want.   The engine does not care where #1 is located as long as the rotor is pointing at the #1 plug at the proper time and all the following wires are in the correct order for your Engine and they circle the distributor cap in the proper direction your rotor will spin. It is always a good idea to have your #1 be in the same spot the factory set it at so the next wrench to touch your engine has an easier time.

A backfire doesn’t go out the exhaust. You’ve got some fundamental misunderstandings and it’s time to get help.

MrMcD wrote: Keep in mind that the engine will be on Top Dead Center twice in each complete cycle. Once for exhaust stroke and once for Compression stroke. you can pull the spark plug in #1 and put your thumb or a compression tester in the hole. Now rotate your engine slowly and you will feel the compression building or see it on the gauge when you approach TDC on the compression stroke. As you look down on the front of your engine below the distributor in your Ford you should notice one of your Heads is about 1" forward of the other head.   The First plug in this forward head is your Number 1 cylinder.   As you feel compression building start watching for your timing mark to come and align the harmonic balancer line with the TDC mark on your engine.   Top Dead Center at your Zero mark. Once engine really is at TDC you can pull the distributor cap off and make sure your rotor inside the cap is actually pointing at the #1 plug wire on the distributor cap while you are at TDC.   If the Rotor is not at #1 you need to adjust.   At this point if you are off you have two options.   Move the Plug wires on the cap to the correct spots based on where your rotor is pointing or unbolt your distributor and lift it up to rotate the rotor to the place you want #1 to be pointing, as you drop it back down you will notice the rotor moves as it settles in, this is normal you just have to try a couple spots till you get it pointing to the spot you want.   The engine does not care where #1 is located as long as the rotor is pointing at the #1 plug at the proper time and all the following wires are in the correct order for your Engine and they circle the distributor cap in the proper direction your rotor will spin. It is always a good idea to have your #1 be in the same spot the factory set it at so the next wrench to touch your engine has an easier time.

Thanks for the reply! If I can find a few minutes today I will work through this, I have some time before the tech will be scheduled.

Turning the ignition off for a few seconds then turning it on when cruising through a tunnel used to make a pretty loud noise out the exhaust.

Riley wrote: Turning the ignition off for a few seconds then turning it on when cruising through a tunnel used to make a pretty loud noise out the exhaust.

Unburnt fuel in the exhaust does make for interesting noise, and potentially popped mufflers. Little different than a backfire but can be caused by the same issue.

Squirt some gas (like less than an ounce) into the manifold (put flame arrestor back on) & see if it comes to life.

IIRC there is an inexpensive fuel injection relay that can fail.

1-2 minutes? Wow that’s ALOT of water.

Correct engine rotation, check.

The water is a little strange so far. It really only enters the boat when I'm running. Sitting in the water and idling there is not noticeable water intrusion. If I run around the lake, boom water in the aft of the boat. I'm thinking it could be from the rudder leaking or....well I don't know. More investigation is needed.