Weird misfire after washing engine bay

[Kdubs88]

Hey guys I have a FBO 135i, jb4 with mhd bef. I just bought the car about a month ago and have been doing some maintenance on it. I did the valve cover gasket, oil filter housing gasket, and the oil cooler gasket, fresh oil and filter, new coils, and the plugs look pretty new so I left them alone. Under the hood was a complete nightmare from the previous owner not taking care of the car.

I disconnected the battery, then covered everything in some degreaser, and pressure washed everything off. After I pressure washed, I took my leaf blower and blew away all the water until everything appeared to be dry. I then let the car sit for a few more hours to ensure everything was dry.

The next morning I started getting a slight misfire. As the day went on it got worse. Inpa shows that I'm misfiring in cylinders 5 and 6. I swapped coils and plugs with other cylinders and the misfire did not follow, stayed right in 5 and 6. After some messing around with the car, the misfire just stopped on it's own and the car ran great for the rest of the day. This morning I went out at 0500 to go to work, and it's misfiring bad again. It's now 10am and it has been bad all day. (I live in Hawaii, it's not really cold in the morning here).

Anyway I'm suspecting injectors, but it's just weird to me that it went away and then came back. I have index 7 injectors in cylinders 5 and 6, and index 9 in the other 4.

What should I check out before buying some new injectors? Could this be due to carbon build up on the valves? I'm sure the previous owner never cleaned them and I plan to tomorrow when I'm free. Could it be that I got something wet that shouldn't have gotten wet? I washed my e90 328i and my e82 x3 the same way and had zero problems. I'm just kinda stumped.

Thanks for any help you guys might offer up.

[iminhell1]

Something got wet. Plain and simple. It needs to dry. Pull connectors and see what got water pushed into it.

[Kdubs88]

Originally Posted by iminhell1

Something got wet. Plain and simple. It needs to dry. Pull connectors and see what got water pushed into it.

So today is day 3 after washing it and it's been getting to over 80 degrees here during the day and the car sits outside. I've unplugged both injectors to check and they were dry, and from what I can tell everything else is dry as well.

If it helps, I keep having connection issues with inpa and mhd that I didn't have before. If I unplug the cable from the car then plug it right back in it reconnects

[Kdubs88]

Bump

[Gangplank]

First I'd change m the plugs to real BMW plugs. Inexpensive and likely overdue if the maintenance was as bad as suggested.

What year 135i & how many miles?

If it's staying in cyl. 5 & 6 when you swap coils & plugs then it's not the coil. Injectors? You said they were mixed index?

[Kdubs88]

Originally Posted by Gangplank

First I'd change m the plugs to real BMW plugs. Inexpensive and likely overdue if the maintenance was as bad as suggested.

What year 135i & how many miles?

If it's staying in cyl. 5 & 6 when you swap coils & plugs then it's not the coil. Injectors? You said they were mixed index?

It ended up being 2 faulty injectors. A buddy of mine gave me 2 of his old injectors (index 9) that were working when he removed them. I installed and coded with inpa and she's back to normal. Thank god.

[Mr Gasser]

Thanks for sharing the injector story...good to know.

[mackeroni]

Originally Posted by Kdubs88

It ended up being 2 faulty injectors. A buddy of mine gave me 2 of his old injectors (index 9) that were working when he removed them. I installed and coded with inpa and she's back to normal. Thank god.

Would you conclude that the under hood cleaning caused the injectors to fail, or was that just an unhappy coincidence?

Peace... Mack