Samuel E Altimore IV

I just changed the intake manifold on my 2008 F150 4.6L. I put everything back together fired it up and it is missing and the engine light is on. I drove it down to the Advanced Auto and had them scan it to see what it could be. I was thinking a bad coil but the guy said it was reading #2 Bank is lean #7 injector is not getting proper air to fuel ratio. MAP sensor and O2 sensor codes also came up. My question is would those injectors just go bad like that? I cleaned everything as best I could before I put it back together. Is it the injector or is it the MAP or O2 sensors or is it all three? I'm really trying to avoid putting this thing in the shop. The injectors are easy to change out and I can do it myself. Any thoughts here? Should I change the injector first and see if that fixes the issue?

depami

What was the reason for the manifold change?

Are you certain the original problem has been resolved?

Yes, an injector can just fail. Or, a connection not quite proper.

Check everything involved for proper connection. Often it is simply something overlooked.

What is condition of engine compartment?

I am currently in the middle of an engine harness change in my '86 928. Everything is so brittle that, any time you touch things, you run the risk of something else failing.

Samuel E Altimore IV

The intake failed and was leaking coolant, at first i thought it was just the manifold gasket until I got it off and then i seen that the manifold was cracked underneath the thermostat housing. I hate the fact that these intakes are made out of plastic. Anyway the new manifold is on and that issue with the coolant leak has been resolved now this new problem has popped up. It's definitely missing and idling a little rough. The code that came up was P070 or something like that indicating a misfire on the #7 cylinder and then is said #2 bank lean #7 cylinder improper fuel/air ratio which makes me think the injector isn't dispensing fuel properly. I don't know all I do know is there was no injector issue before I removed the fuel rails to get the intake manifold out/off.

hetman

swap injector w/ one from the other side

Samuel E Altimore IV

Is that to test to see if it isn't working properly?

Samuel E Altimore IV

I have a noid light test kit and have already tested the injector connectors they're good.

lewissa81

Like hetman said, swap the injector with another cylinder. If the code follows the injector, then you know it's the problem. If you still get a cyl 7 misfire code, then it's not the injector. It's possible that you have an intake leak at that cylinder. That would account for the unmetered air and air/fuel ratio codes.

depami

Did coolant enter combustion chamber?

Maybe a plug is fouled.

Swap injectors first though because a plug removal gone wrong is a nightmare and these things are known for that.

Samuel E Altimore IV

I'll try swapping the injector. And I'll check the plug I seriously doubt any coolant got down in the combustion chamber though. But anything is possible. What would cause the intake to leak? I thoroughly cleaned all the surfaces where the intake and gaskets sit. And I torqued all bolts to the specs listed with the new intake which was 18fp.

lewissa81

Sometimes gaskets get a little marred when installing parts. It's just a possibility. With the engine running, spray some starting fluid directly at that cylinder where the manifold gasket is. Well, as close as you can. Make sure all your electrical connectors are tight first though. If there is a change in how the engine runs, then you'll know the gasket is leaking.
Odds are the gasket is fine, but it is a possibility that should be considered if all else fails.