I'm new to this forum and I just had a shop swap my 4.6 for a 5.4. The reason I swapped the motor was the number 4 cylinder misfired and took a chunk out of the piston. Not sure why but I replaced the motor. Now, I used a 5.4 out of a E350, I reused the 4.6 intake, coils, everything except for the block and heads. I know the fuel and spark map is different for the 5.4 and tried to plug in a 5.4 ecm, but the motor ran like poop. I've been running this motor for a year with the stock 4.6 ecm, not going past 4k rpms. Pretty ****ty, but I'm in Germany and support is poor. I called Troyer performance but the follow up was terrible. Now here is the real problem.....I'm now getting a cylinder 4 misfire, the same problem as the last motor which resulted in a blown motor. I think this is some kind of detonation or how else would a piston crack??? Timing too advanced, or too lean? Why in only the number 4 cylinder?? And why the last motor?? Bad injector?? I would like to get the ecm fixed, but I'm having issues with that. I've been reading this forum for a couple of months and you guys kick ***!

 

Check for coolant dripping down onto the #4 coil. Look closely at the connections to the heater core. What year is your truck and what year was the 350?

JMC

 

I checked for leaking coolant, nothing. The 350 was a 99. 4.6 was a 98. I just pulled the plug and it looked good. If the plug was getting water on it, it wouldnt cause detonation, it just wouldnt fire correct?? I'm just hoping this motor isnt, it doesnt have a knock sensor on it does it?

 

Also, it only happens when it first starts up and has been sitting for a while and has allowed to cool down. It does it around 1300 rpms and about 40-60 mph. It has a loss of power and shakes and the ses light blinks.

 

I don't know what shop you used, but they could not have used a 4.6 intake on a 5.4. won't work.

 

It was a shop on my base here in Germany. That's what he said but I just realized the other day they were morons when one of them told me I need to stock up on UV joints because my new body lift is going to change my driveshaft angle. Ha! Ok, forget the intake, does anyone have any ideas here? I put a brand new plug in it and cleaned the plug hole, still happens. I think im going to swap the injectors around next.

 

No one's got any ideas for me????

 

you need to get a scanner hooked up to the aldl port and check data. the stock 4.6 ecm and program will run a 5.4 but not well. you still haven't corrected your info about the intake mismatch so how can you expect help? We would be glad to chime in if you gave more info. the rear cylinder may have an intake gasket leaking or a bad plug wire if you have wires, or a bad coil if you have COP. Give more info

 

The code downloaded was a p0304 or something like that, ended in an 04. The wires are only a year old, and look good. Not sure about the intake, I thought he had reused the 4.6, but if its impossible, then I guess not. The spark plug looks the same as the rest, but I replaced it anyway and it still misses right after start. Once the truck is warmed up, it doesnt do it. Whether its raining outside or not. I'm working on getting a programmer from Mike Troyer, but I'm not getting any info back. Could this have something to do with a cold starting mode? The coils are accel and are also only a year old. There are no coolant leaks. I know the ecm is not correct for the motor and is throwing the wrong amount of fuel, but why is only the number 4 cylinder missing? Is that a prone cylinder? I'm really stumped here.

 

Have you tried swapping coils?

 

No, its still using the 4.6 dual coils. If one of them was bad, wouldnt four cylinders misfire? I'll try it anyway.

 

sorry i was thinking you had cop ignition. try disconnecting the little condenser on the side of the coil and see if that changes anything. maybe find someone close who has an oscilliscope to scope you ignition wires and see if there may be a fult indicating lean condition or mechanical issue. have you checked the intake gasket? also, check the little vaccuum hose on the rear of the intake below the throttle body, common to be broke