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Hmm that is odd. I would have expected #8 due to the PCV design. The injector would have to be super clogged to lean it out enough to burn a piston. I would definitely check the injectors to be sure they flow the correct amount. I would also check the MAP sensor as well as the O2 sensor. Double check the timing as well to make sure it's not pinging, that could do it too.
The motor was replaced with an old van 302 and they converted it over to the truck fuel injection. I had it no longer than about 2 weeks. and it leaned out so overall it had to of run barely 5,000 miles! How do I check the map sensor and o2 if the motor is not in it? I have a code reader but it probably has erased the codes since the battery was disconnected. It ran perfect no pinging or any type of signal. No check engine light unless it doesn't have one just bought this truck don't know exactly. I've had a bad map sensor before and it just wouldn't even start. And as for the 02 sensor, wouldn't it smoke or barely run or something? Please help thanks for all your input so far. Sounds like you've pretty much know what your talking about. Whats the pcv design? How do I check the injectors? take them somewhere?
That map sensor that was bad was on another truck of mine. Should I just put the motor together and run codes? Please help I need to work. Thanks for any help
Do you know for a fact that it ran lean? If the the check engine light works, it will come on when you turn the key to run, but don't start the engine. Most of the things you can test require the engine to be running, or at least the computer to be turned on, which are difficult to do with the motor out. All the fault codes are gone since the battery has been disconnected. I don't know if you will be able to generate them again without driving the truck. When O2 sensors fail, they just slow down in how fast they show switches between rich and lean, and sometimes go one way or the other - either run the truck lean or run it rich. The truck has to be running to check that, but in your case it might be easier to just replace it with the engine.
The PCV system stock on the trucks dumps into the intake runner for cylinder number 8, which causes more wear and tear in that cylinder than in the others. I don't think that this is your problem.
I don't know if it ran lean but by the way the piston looks it had to of got hot because their is a hole along the side big enough to fit a dime through just about. what do you suggest? Should I just put the motor in and change that one injector and o2 sensor. then put the code reader on it after I get it started. What else can cause a hole on #2 could it be the fuel regulator or The truck ran perfect idled, ran strong. I have an 88 f150 and a 91 f150 and it ran better than both of them. Something went wrong on the original motor and they must have not fixed it or something. I guess I just going to drop it in with another fuel injector for #2 and 02 sensor cause i got a spare. Please help anybody?
You have a new engine ready to go in? I'd go ahead and get it installed and hooked up, but drive it gently for a bit and then see if any codes come up. Check the fuel pressure and flow to be sure they are up to spec, and make sure the timing is correct. I don't think it will hurt anything to swap out the injector, just to be safe in case the old one was indeed bad.
I have to say that I am having the same type of problem.
91f150 302 and when I bought the truck the drivers side far back piston had a whole along the edge.
I purchased a donor truck and stripped the intake & fuel rails off my motor and placed them on the donor motor.
Motor ran great for about 1 month probably less than 1000 miles and then the same cycl is now dead again.
I haven't yet tore into the motor the second time. Truck runs but compression on that cycl is 0.
What caused it? Fuel injector? (because I did use my original fuel rails and injectors?
Is there a way that a shade tree mechanic like myself can test the injectors?
PCV system is probably to blame for the number 8 cylinder (far back on drivers side). Re-route the PCV to the main vacuum tree and plug the port in the back of the manifold to fix this problem.
I understand if it was the # 8 cylinder about the pcv design but mine is # 2 I'm just going to put it together and hope for the best
also another question what would happen if i couldn't get the converter in the same exact holes on the flywheel?> what do i do? shady tree mechanic also.