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got wet. need help

bullfrogp

NAXJA Forum User
Location
florida
After sinking yes complete submerging. I can't get any spark?
I drained and refilled all fluids. Blew all connections out with air.
1989,4.0, automatic.
 
Gotta tell you. This can be very challenging as water and electronics don't mix well. And even when you get it running, you are likely to have electrical "gremlins" down the line.

Electrical contact cleaner in EVERY electrical connector for every engine management sensor, and all electrical connection is a good start. This stuff is available anywhere, even Wally World.

New distributor cap and TPS.
 
Gotta tell you. This can be very challenging as water and electronics don't mix well. And even when you get it running, you are likely to have electrical "gremlins" down the line.

Electrical contact cleaner in EVERY electrical connector for every engine management sensor, and all electrical connection is a good start. This stuff is available anywhere, even Wally World.

New distributor cap and TPS.

Good advice here. If you don't refresh every connection as recommended, the gremlins will hound you forever.
 
make sure you dont feed them after midnight =]
 
I thought WD-40 was a bad idea for electrical connections?

IIRC, it does displace water, but leaves a film over the metal contacts (to keep displacing the water). On electrical contacts this creates more resistance in the circuit.

You will more than likely run into MORE electrical gremlins down the road if you use WD-40. Electrical contact cleaner is all you should be using.
 
The 90 and earlier ECUs are not waterproof... they are under the dash, it's the big aluminum box over the gas pedal. Remove it, carefully disassemble, only handle the circuit board by the edges. You'll want to clean it somehow if there is a significant amount of residue on it, if it has corroded you get to replace the ECU entirely. I suggest rinsing it off with isopropyl alcohol (rubbing alcohol is a good substitute) then allowing it to dry thoroughly.
 
The 90 and earlier ECUs are not waterproof... they are under the dash, it's the big aluminum box over the gas pedal. Remove it, carefully disassemble, only handle the circuit board by the edges. You'll want to clean it somehow if there is a significant amount of residue on it, if it has corroded you get to replace the ECU entirely. I suggest rinsing it off with isopropyl alcohol (rubbing alcohol is a good substitute) then allowing it to dry thoroughly.

this

and after that you're probably looking at replacing the TPS if it got wet, and possible the MAP sensor if it ingested some water too.

If the ignition module had a crack in it and got water in it you'll be replacing that as well. Get out your multimeter and start testing sensors/ignition module.

and have fun removing the Renix ECU, you have to stand on your head for a bit, and the mount was slightly over-engineered by AMC.
 
I thought WD-40 was a bad idea for electrical connections?

IIRC, it does displace water, but leaves a film over the metal contacts (to keep displacing the water). On electrical contacts this creates more resistance in the circuit.

You will more than likely run into MORE electrical gremlins down the road if you use WD-40. Electrical contact cleaner is all you should be using.

This is true. WD-40 is for displacing moisture like in a distributor cap. Electronics cleaner is for electrical connections.
 
The 90 and earlier ECUs are not waterproof... they are under the dash, it's the big aluminum box over the gas pedal. Remove it, carefully disassemble, only handle the circuit board by the edges. You'll want to clean it somehow if there is a significant amount of residue on it, if it has corroded you get to replace the ECU entirely. I suggest rinsing it off with isopropyl alcohol (rubbing alcohol is a good substitute) then allowing it to dry thoroughly.
Thats exactly what I have done but I think it is fried. do you know anyway to test it. i don't realy have the money to start throwing parts at it.
 
Thats exactly what I have done but I think it is fried. do you know anyway to test it. i don't realy have the money to start throwing parts at it.

OK!!

First, clean EVERYTHING, use electrical contact cleaner and dielectric grease.

Second, test EVERYTHING: http://www.lunghd.com/Tech_Articles/Engine/Basic_Sensors_Diagnostics.htm

Things that will kill spark: POOR GROUNDS; crank sensor; B Latch relay; ICM/coil; harness.

As already mentioned, clean all of the contacts, and don't forget inside the distributor.
 
WOOHOOO! GOT IT. It was the computer. I did everything you guys said and it worked .cleaned everything with conection cleaner,air. Irealized that the day after I sunk it the fuel pump worked to get the fuel/water out of the tank but by time I got it back in the garage it didn't. When I took the computer out from under the dash it still had water in it (Becouse it's mounted with the plug opening on the top bad idea)any way I got a computer from a freind put it in and magic. THANK YOU ALL.

I wish I could show you guys the pics.
 
Yeah, those stupid Jeep engineers and their bad ideas. They should have anticipated that these things were gonna be used for submarines someday. They sure had their priorities all messed up mounting the ECU the way they did.
 
Yeah, those stupid Jeep engineers and their bad ideas. They should have anticipated that these things were gonna be used for submarines someday. They sure had their priorities all messed up mounting the ECU the way they did.

places for water to pool are generally a bad idea, things like condensation can wreak havoc on electronics if there is nowhere for water to go when it collects. look at the later model ECUs in the engine bay, they are not sealed but have drain holes in the bottom and vent holes on the side ;)
 
yeah... apparently chrysler actually did something right, hell in '96 they made the ECU 100% waterproof and also waterproofed its connectors. The TCU and all the other electronics are still vulnerable to overly enthusiastic mudding though.
 
places for water to pool are generally a bad idea, things like condensation can wreak havoc on electronics if there is nowhere for water to go when it collects. look at the later model ECUs in the engine bay, they are not sealed but have drain holes in the bottom and vent holes on the side ;)

I agree. But, his ECU is up under the dash at knee level in the passenger cabin on an 89. I doubt the engineers anticipated having to deal with flooded ECUs at that location............
 
Yeah, I'm with cruiser54 on this.

An M151 with a fording kit--no problema, make a submarine out of it. The XJ and non-military versions of the CJ were never intended to be put through what some of our rigs see.
 
If you want to talk about dumb locations for PCMs, happends to be a Chrysler product, older Dodge Neons have the PCM right under where the fill hole is for the washer fluid. lol Glad your junk works again!
 
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