Chucka'Rod

Cyl #6 misfire code, swapped injectors, coil packs, spark plugs with opposite bank with no change and new fuel filter. The misfire is intermittent and is noticeable at all RPM and loads. Removed ECU and found some white corrosion on a few terminals on a plug on the back side. The result of water leaking from somewhere above it. (Ford TSB 08-26-7) I assume that the ECU is bad. I've read a few other dead end posts on here where the OP never came back and said wtf they found. Any other suggestions before I replace the ECU? Thanks!

Derf00

That's a pretty big assumption without a scope or Ford system to verify that. The TSB you're referencing has nothing to do with the PCM (What you're referring to as an ECU). The TSB is for a water leak in the passenger compartment. It would not affect the PCM but it could affect the SJB (Smart junction box) in the passenger kick panel. That would usually create accessory problems, not misfire problems.

What's the specific OBDII code you are getting? It may help narrow down the issue.

Since you've already gone through and swapped things around it leads me to believe it could be a cylinder or head problem. Perform a compression test and if that finds that the cylinder is low, perform a leak-down test to find the source of the problem.

Also, how's your coolant looking (muddy) and how's your oil looking (milky)? That would be a blown head gasket. Again a compression and leak-down test would help find the problem.

bl817

this could also be an injector or coil pack wiring problem. and as Derf stated, a compression check will rule out cylinder or head/valve problem. good luck

Chucka'Rod

Coolant and oil look fine. I have to buy the Ford adapter for my compression gauge. I don't remember the exact code # just that it said cyl #6 misfire. I assume the PCM judges a misfire by calculating the difference in RPM between cylinders using the crankshaft and camshaft position sensors? At first I was thinking it was something electrical, not mechanical. I don't have time to fix this **** box if it's a head gasket. It'll get sold as is.

Derf00

For a generic misfire code i would think so but, newer fords and probably most other mfgs can also sense a bad coil circuit and call it out with a different misfire code. For that they use a feedback loop system through the PCM driver and a ground point. That's why the specific code is important. If it's a general misfire, old school troubleshooting works fine. If it's a coil specific misfire that gets into the electronics/electrical system. Easiest method being a Scope.

millhouse961

I had the same issue in my #3 cylinder and finally fixed it yesterday by re-flashing the computer. Guy at my local shop told me this morning they see that (need for reflash) all the time in foreign cars they work on. I would try that next

Chucka'Rod

Is the problem still fixed or did it reoccur again?

millhouse961

Problem seems to be solved; was able to get the car smogged too. If you have a tuner, the reflash is simple; you can even load a tune and then take it back to stock and it should be fresh

Chucka'Rod

I'll have to find someone with a tuner. Mine is bone stock with no mods. I've been wanting to get an SCT tuner, but for a different car.

millhouse961

The tuners are programmed to the vin of the car they are for so that's not gonna work. If you go to your local ford dealer they should be able to reflash the ecru for you