Hi FRF,

I've read the forum in the past but I'm new to join so I apologize in advance if this is miscategorized.

I was driving to a trailhead last weekend and hit a creek crossing too hard. Maybe a foot and a half deep, but water splashed pretty high. Immediately after leaving the water I heard like a gear stripping sound, I knew the danger so I shut it off right away. A guy who claimed to have been a mechanic was driving by and I explained my situation; he said he was more worried about my electricals (distributor) than my intake. Either way, I checked and dried that, the battery, and the intake and filter and drove it with almost no problems (but the occasional cough) for another 5 miles or so out of the hills, but it started coughing real bad when climbing the hills out to the main road. It got so bad I called a tow back to town before I could get to it. By this point, the check engine, check oil, and battery lights were all on. Probably didn't help that I was pretty low on gas but I know I had about 40-50 miles range left and I did check oil and coolant. The truck wasn't leaking noticeably, or more than usual.

I was able to start it in my driveway and pull engine codes. Still ran rough, bogging every now and then, but I got the following:
114: Air charge temp sensor voltage high or low (by the way, where is this located?)
10: Cylinder #1 has a problem
157: MAF fault, low voltage
543: fuel pump secondary circuit fault.

Battery voltage was steady above 12V when off and 15V or so when running.

A few days later (it's been raining a lot and I don't have a garage) I was able to go out and check again, and ran more tests after adding a gallon of 91 and some HEET (methanol additive?), my latest theory being that maybe water got in the fuel tank or lines. I pulled the plugs, which looked black but normal-ish.
I messed it up worse by dropping the MAF while cleaning it, so I have a new one shipping in any day now. Anyhow, ran some tests and got the following:

Key-on Engine-Off Test:
10 ,157, 543
Key-on Engine Running Test:
998 (failure mode), 157 (MAF is the sensor that failed)

The engine ran but would bog down every now and then or run off-balance and just wouldn't run well. Smelled like it was rich.

This being said, what steps should I take to get this thing back to normal? I plan to replace the MAF, the Intake Air Temp Sensor, fill the tank if I can get it to run all the way to the station, dump the rest of the bottle of HEET in to clear out any water... Maybe replace fuel pump?

TL,DR: I drove my '94 through a creek too fast, it got wet. Now it runs real rough and gives me error codes for the MAF, ACT, cylinder 1, and Fuel pump 2ndary circuit.

Thanks for any help you can offer.

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'94 XLT 2WD 4.0L (OHV?) Super Cab
Pretty much stock. Have a camper shell and some LEDs. Still kickin' at 240k miles.

Mechanical engineering student with some wrenching experience.

My other truck is a '91 CBR600F2.

First thing you might want to try if you haven't is disconnecting the battery completely for about five minutes both hot and negative. Then reconnect and let it run this should clear any old codes that might be stuck in there. Next is post some more info what year what engine and drive train.


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Just take the cables off hold them together for a minute and put back on that will crush the ECUs memory
Change your oil and let the truck get a nice sunny day for the electronics to dry

Never heard that one before how does that work by holding them together is there some type of memory that it clears?


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Just dealt with a 91 Yota 4X4 4runner buddy that didnt make this crossing, let alone having to come back for him a 2nd time.. [NOTE - No snorkel and on the return trip you can see water clearly over the emblem in the grill with 33" Dynapro MT's, 2" lift, 2" Body lift on it.. and 2WD



His issue, 1.5 yr old battery dead, Starter and coil survived. R&R spark plugs and cranked over to eject water from cylinders, took entire intake hose assembly out to drain each of the 3 air reservoirs (which made me want to drive my truck straight through the Toyota engineering dept on the foresight of repairing a vehicle they engineered to be just utter shit to work on btw), changed oil which was full of water too. Since the oil floats on top of water, the water rushed out first upon draining it; we replaced the oil filter.

You may have water in the oil pan, I did not see where if you changed that or not. but that could be your "water on the lungs" cough...

Hard to say without seeing it in the condition it is.

What part of Cali are you in?

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If you sucked up water and took out the MAF sensor, more water may be prevalent deeper.. just my $ .02 here..

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+ 93' Ranger Overlanding Build
+ 94' Ranger Bed Overlanding Trailer Build
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DISCLAIMER: I'm not an expert with the electrical stuff, but I've learned quite a lot about it.

That being said, here's what I'm pretty sure is happening. If something I say is incorrect, please jump in and correct me anybody.

The on-board computer is saving long term fuel trims and such when you only disconnect the battery. Holding the two cables together discharges the entire system and when you reconnect them and start the truck back up, the engine starts completely over with factory defaults and will learn the fuel trims as you drive. Check out YouTube for some videos on this. But before you get to that step, it sounds like you need to figure out what's going on with your other codes first.

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2003 XLT 2WD 4.0L V6 SOHC
K&N Intake

The thought behind touching the cables is to give the current a place to travel. Most mechanics who want to discharge a system like this connect a test light to one terminal and clip it to the disconnected terminal. That makes the test light use the remaining voltage in less than 60 seconds.

OP the rough running is likely either crud on the MAF or water in a cylinder. Water does not combust and no additives will remove it. Pull the plugs and inspect the cylinder. A borescope will make it a lot easier

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White 1998 Ranger XLT SuperCab 4.0 4x4 StepSide

Yes it drains the ecu. So it doesn't have a memory of everything.

Alright, thank you all, I apologize for the delayed response.

It's been raining here a lot and in waiting for the new MAF and IAT sensors to ship in I haven't been able to do much to it in the driveway. Luckily we had some sun the past few days and I after things shipped in I did install those sensors but didn't have time today to give it a good running test. I think I did reset the computer by unplugging the negative terminal, and after I installed the sensors I only had time to do a quick KOEO test. This one was interesting:

It initially flashed me the 111 all clear code, which I thought was strange, but after a while it gave me the same 010 error from before about Cylinder #1 but the MAF and IAT faults were gone. The fault about the fuel pump was also gone. It did, however, toss me a new fault code, something like 512 "Keep Alive Memory (KAM) fault". .. I've never heard of KAM, anyone have insight?

Will post an update tomorrow when I try to run it. Cheers and thanks for the help!!

P.S Undrst8ed I'm on the central coast, you? and that's a hell of a water crossing, a bit deeper than what we were in!

EDIT: Upon quick Internet research, it appears that the KAM is kind of what a_hynes mentioned, the computer's learned parameters from running. Looks like the next step is just to run the darn thing. Might change the oil first just to be safe, per 63merc's recommendation.

__________________
'94 XLT 2WD 4.0L (OHV?) Super Cab
Pretty much stock. Have a camper shell and some LEDs. Still kickin' at 240k miles.

Mechanical engineering student with some wrenching experience.

My other truck is a '91 CBR600F2.

That was our planned trail on the "Mojave rd." as I was leaving for Vegas on a permanent aspect. Our portion was suppose to be a 162 mile trek but got cut short due to my trail partners 4Runner going down and a day and a half of repairs and he was headed to Utah. Only got through about just under 70 miles of it I think. I have to check the way points on the topo map

To be honest I had no idea how deep it really was but after making it through once, well you know.. the Kohonas get all big and shit. lol

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_______________________

My Build Pg. Threads
+ 93' Ranger Overlanding Build
+ 94' Ranger Bed Overlanding Trailer Build
+ 12° North Industries ~ I Support

Most rewarding thing about working on the Ranger: Getting less and less codes as you fix problems! Good luck man, let us know what happens!

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2003 XLT 2WD 4.0L V6 SOHC
K&N Intake