Another Water Related Elrctrical Issue

[Not_An_Abba_Fan]

Have been racking my brain and doing a lot of searching and haven't really found anything similar to my problem.

I have an '89 RRC with 3.5L fitted with 3.9L manifold and EFI system. A couple of weeks ago we went out on a run and it was good all day. On the way back to the highway, gave it some stick along a track running through a few puddles. Within a minute it dies. I thought it must have splashed up on the ignition somewhere. I stopped, popped the bonnet and had a look around but couldn't really see anywhere that was wet enough to cause a problem. Started it up and wouldn't idle or rev. Gave all the electrics a good spray and no real change. Then it started and idled fine but wouldn't rev, like it was out of fuel. The first thing I thought was the fuel pump had died. But the funny thing is, it got progressively better each time I started it.

When starting, it then would rev OK for about 3 or for seconds, then splutter and not go over 2000rpm. The idle would hunt like a big arse cam was in there. It stalls, then immediately start it up again and it revs fine for a few seconds, then starts spluttering and hunting on idle.

A few more attempts and it then it would hold revs fine and idle fine. Drive off and only got about 100m and it dies again. Started straight back up and revved fine. Idled OK for a few seconds then the hunting would start again and it stalls. This time it held revs fine, just wouldn't idle. We only had about 500m to go to the air up point, so I keep it in second with the revs around 3K and it was good all the way. Stop and it hunts and stalls. Start straight back up again and it idles fine. I have on board air, I flick the switch and the clutch doesn't engage. Separate issue. When sorting that out, I must have bumped the fuel pump fuse as it dies and doesn't restart.

Getting a bit ****ed by this point. Fix that and the car starts, idles and revs fine. Reinflate the tyres and drive the 40 odd kms home and it didn't miss a beat.

Any thoughts on where to start? I know it would be electrical, and I know it won't be the ignition system as it ran, just not well. It sounds like a fuel issue but it only happened after driving through puddles.

[bee utey]

Water in the connector to the MAF? When the connection fails it instantly goes into limp home mode. Restarting always clears the fault until it reoccurs.

[PhilipA]

Water in the air cleaner element.
If you have the snorkel /inlet still on the barrel aircleaner it is possible for it to ingest water through puddles at speed.

When a mate lost an engine at 80 Kmh on a dirt road with puddles, I fitted a real snorkel.
Regards Philip A

[Not_An_Abba_Fan]

I thought about the MAF, I sprayed the connector with silicone spray, didn't make a difference, but I don't remember actually unplugging it when I did. That makes the most sense to me as the MAF is pretty much directly above the inside of the passenger tyre. I do have a rubber flap to block the gap around the shock turret but it's still possible water got up there.

I have a snorkel directly from the MAF to a pod filter on top of the snorkel, no way water can get in there.

[Meccles]

Silicone spray is not the best at water displacement. There are better options for water displacement sprays. WD40 still works ok at that.

[Not_An_Abba_Fan]

I have heard that a few times now, but that's all I had on the day. I now have WD-40 in the car.

I had this discussion with different people and the general consensus was that spray everything with silicone spray before hitting any water and it waterproofs the electrics. I had been doing that with no issues, I didn't use any spray on anything this particular day though.

*EDIT* Just read that there is an electrical grade silicone spray which is different to the lubricating one. I only have the lubricant.

[Meccles]

Agree that using it to waterproof prior to getting wet is good :)

[FisherX]

I had the same kind of problem with my old 93 RRC. In my circumstance it was my injector wiring. The outer sheave on the injector wiring was cracked and would allow water in and sit on the top of the injector plug and short out the injectors.

[Not_An_Abba_Fan]

I'll find out this weekend if it does it again, have a little trip planned for Sunday and it's going to be very wet over here.

[Not_An_Abba_Fan]

After a pretty wet day yesterday, I'm happy to report the car didn't miss a beat. I even went through a water hole that was almost up to the headlights. Apart from snapping my tie rod on a stump and the circlip coming off the shifter so I couldn't shift into 1st, it was a good day.

Luckily the tie rod broke right where the thread ended on the tie rod end so I could remove the broken bit and screw the tie rod end back into the tie rod. Only went in about 15mm but it was enough to get me home.