91 F150 XLT Lariat, 4x4, MAF and 351w swap, running an A9L ECM
Truck Performer 5.8 Intake manifold, GT40 heads, long tubes

So awhile back I sank my pickup pretty good in a puddle, nosed in. Water got into the intake but none got in the cylinders as far as I could tell. Farthest it got was the throttle body, maybe a bit into the intake manifold.

After that I replaced the Cap, rotor, wires, MAF, plugs looked good when I pulled them to check for water. Just cleaned out the PCV when I pulled the codes.

It has been coughing and sputtering under load, I dont think it changes with either tank. I think it started shortly after the swim and getting more noticeable since then.

Codes:
67 o
79 o
82 o
85 o
10
33 c

 

Possibly clogged up your catalytic converter?

 

No cat, 2.5" true duals

 

It you went nose deep into water to the point the throttle body was in the water its a safe bet the computer took a bath too.

First thing I'd do is pull the computer and see what it looks like.

If it sat stuck in that water long enough it could have filled the computer housing with water, it is not sealed it is not water tight.

That small list of code have nothing to do with issues you describe.

Couple of them simply user error and some of them possibly due to the fact those sensors are no longer present or no vac supplied to them/unplugged.

Is TAB/TAD there? if so are the electrically active?
Canister Purge Solenoid electrically active and with vac line connected to it?
How about the EGR valve same for it? reporting it is not opening so not a problem per say as long as it is fully closed.
A/C was On during the test?
Manual transmission? didn't hold the clutch pedal to floor during test?

Appears to be a mix of KOEO CM and KOER, point is you can disregard those at least for now nothing there "mission critical" so to speak. You can correct some or all of that if you wish but again nothing affecting it to point causing it to run poorly underload.

Over and above all that sounds like you need to let it idle with the hood closed let the engine heat dry everything out under the hood real good, if in water that deep you got stuff wet that shouldn't be wet and it is still wet.
If the computer was filled with water and is still wet, you stand a chance of frying it by simply turning the key to "run".

 

Completely agree with danr1.

I would have pulled the PCM ASAP, right after the truck was out of the water/mud, whatever.

Next would have been to unplug all sensors and use CRC Electronic cleaner on all sensor connectors.

Guess being paranoid and over cautious has to do with not being to afford new stuff so I have think about what happens next instead of making mistakes and then fixing the damage...keeps my wallet from becoming lighter!!!

 

Ill check that out tonight

Well it was a month or 2 ago and Ive been using it ever since, but figured it might be what started the issues.

Would an O2 sensor cause anything like this? Im running 1 jumped to give the signal for both banks.

Test the fuel pressure? I saw someone else had a similar problem but it was his in tank pump, mine does it on both tanks about the same

Picture of the sinking, only a bit of water came into the cab, and the PCM wasnt under water I dont think. Almost caught a fish on my hood when I splashed in but it went back in the water

 

Id say TPS

 

That has been on my mind

 

You made it sound like it went in quite a bit deeper than what that picture shows (unless it had been partially retrieved at the time of that picture) it didn't get submerged which is a good thing.

It did however get a bath from the cooling fan, beyond that you pretty much did what you should have. Cap, rotor, wires plugs making sure the distributor was good and dry. I'd have to say the angle of the water line nothing of grave importance got wet beyond fan spray. You should be able to tell a water line should show lightly on the firewall etc.

MAF sensor get wet? it would have been above the water line if installed in the stock location? You state you changed it, a new replacement or a known good used one? Did you clean its sensor rod with MAF cleaner?

It be worth testing its fuel pressure along with looking more into that MAF sensor as possible cause of your symptoms. Take a minute to first eliminate fuel starvation due to failing pump though.

 

It splashed well over my hood and onto the windshield, I think I was able to back up a bit before the engine died trying to suck water through the air filter, water made it up to the TB at least.
MAF was pretty soaked, I tried spraying it out several times, I replaced it with a new one off Amazon, Pro-Spec, probably cheap crap. Should I have sprayed it out before installing?

 

You need to make sure you use the proper maf with the maf curve you have in your tune. If you changed this to MASS Air, can you do any data logging?

 

Yea it sucked a little in due to the wave when you hit the water and again when the wave returned.

Had it directly sucked in water with the air intake submerged it would have instantly hydro locked the motor, it runs now so we know it didn't submarine that deep!

+1 with RIKIL comment, dry out the original MAF sensor clean it then put it back on and see what if any difference that makes.

The fact the problem surfaces "under load" suggest it's the problem and or a fuel delivery type problem. You state either tank so lean toward the MAF and even more now reading you put some universal type sensor on in place of the original.

It might have got wet yea probably took a real good bath but the important parts of those are sealed pretty good, only part exposed is the sensor rod (same time that might have been all it took...).

Make sure its completely clean and dry then give it a shot see what how it runs.

 

No, I'm running just stock A9L mustang computer, with a stock 96 5.0L pickup MAF.

Could that be some of the issue, maybe find a MAF for a Mustang, I think the ECM is from an 89.

 

In the ECU is a table called the MAF curve. When the MAF reads the air passing by, it reports a certain voltage to the ECU. That voltage translates to a volume of air. The fuel given to the motor is based on this volume of air.

If you have a MAF that is calibrated differently, that will tell the ECU a different volume of air and result in a different amount of fuel. The MAF sensors are calibrated for a certain air housing they are mounted in. If you have the wrong calibration you can see the behavior you are experiencing.

Don't forget to replace the TPS. That is an easy fix.

 

So besides data logging software, is there a way to make sure I have a correctly calibrated MAF?