Deep water crossing electrical nightmare!

[68rockcrawler]

I hit some pretty deep water last time I was out wheeling and it killed my Bronco. It ran fine for about 20 minutes after the water crossing but after that it started running rough and dying on me. It felt like it had a clogged fuel filter but that would be way too simple! Now it also has no spark and won't run at all, but it turns over good.

Here is what I have found after lots of diagnosing and researching:
1. Very low fuel pressure at the fuel rail. I'm guessing only a couple of psi.
2. 12 volts going in to the MSD offroad ignition box, but no voltage coming out of the ignition box.
3. 0 ohms of primary resistance across the coil and 2.9 ohms secondary resistance which is way lower than it's supposed to be. I have an MSD coil.

So, is it possible this water crossing killed my fuel pump, ignition box and coil all at once?

 

[DirtDonk]

What type of fuel pump? Engine driven standard type? Or low-mounted electrical. (edit: just read your details and see that you're EFI, so electric fuel pump)
If a standard mechanical on the engine, it's pretty rare that a water crossing could hurt it. I suppose if water went into the vent hole with enough time, the diaphragm could have ruptured, but other than that, they're pretty robust.

Electrical-wise, even the MSD 6 boxes are water tight (other than the rev-limiter port perhaps), so it's hard to say what type of shorting might have caused it.
The most likely culprit initially is the distributor. Even a Duraspark can be compromised by water intrusion. Not forever, but at least until it dries fully.
For that, shoot a bunch of compressed air and maybe some WD-40 into it, just to make sure.

For the coil and ICM (MSD box), maybe some others will have some insight.
But at the very least, disconnect all connectors and anything remotely related to the ignition and use compressed air and/or WD-40 on them to get rid of any residual moisture, and go from there.

Good luck. The fuel pressure is a puzzlement for sure.

Paul

 

[DirtDonk]

Now that I see you have EFI, is your pump on the frame or in the tank?
If on the frame, is it mounted low and close to the tank? If not, then it might just have lost it's prime temporarily.

Paul

 

[68rockcrawler]

Fuel pump is a high pressure on the frame rail near the tank.

 

[68rockcrawler]

It's been so long since I installed the pump I don't remember how to prime it.

 

[Viperwolf1]

The coil readings are too low. Did you have all the wires off when you measured it? If so its toast.

 

[68rockcrawler]

Yes, all wires off when I measured it.

 

[707Bronk]

Is it possible that water got into the fuel tank?

Have you checked your oil? Maybe water got into there as well?

This won't affect our ignition issues, but might affect it running rough in general.

 

[68rockcrawler]

I guess it is possible that water got in my gas tank and oil. I could throw some fuel dryer additive in the tank. I sure hope I don't have to pump out 12 gallons of liquid gold and get rid of it!

Oil looks fine on the dipstick but I'm about due for an oil change anyway so I'll do that just to be safe.

 

[DirtDonk]

One good thing (or at least less of a negative thing!) is that you might not even have to resort to "pumping" the tank empty. Most well designed tanks will self-empty once you get the flow going and the end of the hose is lower than the pickup.
Just did it this last week to a NWMP tank and literally had to flip it on it's side to stop the flow!
This was with only ten gallons in it, and that 3/8" hose just sucked that gas right out of there in a few minutes.

Good luck. Can't wait to hear what all you've got going on there.

Paul

 

[Timmy390]

I use a fuel primer bulb from a boat to get the flow started and then let gravity do the rest.

The water (if there is any) will be at the bottom of the oil pan and the fuel tank. No need to toss the gas, just drain the tank and put the gas back in minus the water.

Oh and stay out of the water.....sharks in the water....LOL

Tim

 

[68rockcrawler]

I haven't had a chance to drain the oil or fuel, but spent a few minutes doing another test on the MSD box. I had only checked the main power wire going into the MSD box directly from the battery, which I already knew had 12 volts. Tonight I confirmed there is 12 volts coming into the box from the ignition circuit. So, I am getting power from the correct places, but definately no power out of the box. So, is it fried?

 

[68rockcrawler]

I replaced the coil and still can't get it to start. There is still power coming into the MSD ignition control box but no power coming out of it. I put this box in when I dropped the EFI in. I have done a bunch of research on this but really don't understand what to put in to replace the MSD box and go back to stock. From what I have read this box really isn't doing much for me since my engine is stock.

 

[roan65]

Are there any codes? Any chance the computer got wet? Check for water in your electrical connectors, and use dielectric grease to help keep water out.

 

[68rockcrawler]

There are only a couple of codes, but they are the same ones that I have had since I installed the EFI and supposedly ones that aren't a problem. I have dielectric grease in most of my non watertight connections. I will grease the rest of the connections.

 

[Broncobowsher]

only a few PSI in the fuel rail. Of course you will have trouble starting it. EFI needs puel pressure. Without that the engine is not going to start or run. Have you tried starting it with carb cleaner or brake wash down the throttle body? Just make sure you are using the flamable kind, non-flamable stuff isn't a very good fuel.

 

[68rockcrawler]

I forgot to update that. I actually do have good fuel pressure now. I have tried starting it with starter fluid and it didn't work.

 

[Keek]

Something we did once with an old E-350 Van when the ingition box acted up.

We put it in the oven at the lowest oven setting and left it overnight.

This dried it out and it worked fine for another 100,000 miles or so before we sold the van for scrap.

 

[68rockcrawler]

Something we did once with an old E-350 Van when the ingition box acted up.

We put it in the oven at the lowest oven setting and left it overnight.

This dried it out and it worked fine for another 100,000 miles or so before we sold the van for scrap.

Wow, I'm a little nervous to try that. Plus it's an MSD offroad box which I have heard is all sealed inside.

 

[patterdale]

You didn't mention how deep. Anything over the rockers and all bets are off. The fan will spray all over anything electrical under the hood. I can't even begin to imagine what happens to an EFI/computer system when stuff gets wet.