loss of power/ bucking in rain
 

I had a strange incident today. I was traveling for work and was driving most of the day. On the way home I was driving in really heavy rain. I stopped for gas and as I was pulling away from the gas station the car lost power around 4000 RPM's. It was like the power was completely cut and the car bucked violently.

This happened twice more before I got back on the freeway. I kept the RPM's down and made it home fine. When I got on the back roads near home I tried to get it to do it again. It did, just not nearly as severe.

My only mods are a Jackson Racing Supercharger with the carb tune.

I called Jackson Racing and their thoughts were maybe a coil pack going bad. I don't see anything amiss under the hood and it did not seem wet under the hood.

I hooked up my scan tool and found no trouble codes.

I would simply replace the coil pack if I knew that was it, but without a code I won't know which one.

Open to any ideas

Thanks!

Pat

Update: answer found!

I believe I figured out what the issue was.I actually have de-modded my car and have sold it since then. I did not realize this until I was boxing up my supercharger when I sold it. I saw water stains inside the pipe going from the intercooler to the engine, like water had gotten that far and was running back down.

The car acted as thought it would if the MAF was wet, and I guess the maf was wet. It seems unlikely that the water would have gone though the air filter, super charger, intercooler and all of the pipe to get to the maf, but that is what I now believe happened.

TC kicking in?

What speeds/gears does this happen in?

How many miles are on your car? What type of fuel are you using?

Feel free to give us a call.

Failing coilpacks definitely throw a code (although I suppose they could cause problems without triggering a code), when mine generated a CEL there were no indicators aside from the light that anything was amiss. Certainly no bucking or power loss (It triggered in turn 5 at Laguna Seca) and it was perfectly fine for 2+ weeks afterwards.

I'm old, I know how to drive in the fucking rain, and I'm way better at it than the goddamn computer.

Rained like cats & dogs all the way home from the Bay Area. 8 hours.

2 hours into it I said "Fuck that noise" and pedal-danced it the rest of the way home. My wife also immediately noticed the improvement.

At no point did the TC light ever blink. That's bullshit, intervening and not telling you. Not OK, Computer. Not fucking OK.

Maybe the gas station sold you some water along with the gas ....... :popcorn:


humfrz

DANG ..... @Ultramaroon, watch your blood pressure now ..... :eyebulge:


humfrz

I'm tellin' ya it's fuckin' BULLSHIT, man!
http://i.imgur.com/5YLDrOG.png

I can't rule that out 100%. I did not see the light on the dash when it happened though. This was strange because it was violent to the point of almost losing control of the car.

That sounds familiar.

I don't think that was it.

I drove the car in the rain again today and no such issues. I talked this over with CSG mike last night and he suggested I may have a spark plug going bad. I do have almost 50,000 on the car with about 10,000 boosted.

If this was a coil pack going bad I would have a trouble code, which I do not.

I think I will throw a set of plugs in to be safe, though I did drive a couple hours in the rain today and I could not duplicate it.

Thanks for the input guys!

Pat

Well now, I think that would be a good idea.

As for "throwing in" a set of plugs ...... :eyebulge:

(back in the day, that was a 5 minute job ..... even if you were slow ....;))


humfrz

It has to be heavy rain so the TC senses some hydroplaning. The trouble for me was that I know how to handle that so the computer kept throwing me off of my game.

Do you have a CAI that doesn't account for wet weather? What flavor of boost?

Hey, I remember 6 Volts & big fat cables.

I understand it will be challenging, but I have a great set of tools, patience and experience.

I have a Jackson Racing Supercharger. The air filter is close to the stock location. It did not appear wet.

When this happened I was pulling out of the gas station on the way to the freeway. It happened under moderately heavy acceleration at about 4,000 rpm's.

It was quite upsetting because it felt like the traction control kicking in, but like a total cut of power. Then the power kicked back in and lurched the car. It was very violent.

Maybe I picked up some oil on my tires as the gas station?

I may as well do the plugs anyways. I think they are only good for 60,000 miles

Pat

You spoke of driving in the rain ..... I recall the vacuum powered windshield wipers that STOPPED when you were passing another vehicle on a two lane road (for the younger ones ..... since the wipers were vacuum powered, they would stop under heave acceleration, because the engine was using all of the vacuum).

Yep, that’s when we had to “drive the car” …… single piston master brake cylinder; bias ply tires; 6-volt headlights; lousy shocks; 85 HP (on a cool night) and no power steering or brakes.

NO NANNIES …… just driving skill ……:burnrubber:

humfrz needs a nap because he is ....... :offtopic:

My GF has a 66 bronco (Inline 6).. I know exactly what you mean.

Wait, you had a windshield? So spoiled. :cheers:

Hey, I wrote almost that exact rant in another thread! Plagiarist. Oh wait we drove the same sort of cars that is all. Nevermind.


The vacuum wipers did make up for stopping by going like hell as soon as you took you foot off the gas. That is until they flung off into the netherworld. Looked funny lurching down the road to keep the wipers going.

Gonna throw in my 2 cents in support of Hums water in the gas theory. What you described nails my past experiences with that situation. Also explains why the problem lessoned and then disappeared even in the rain. A bad plug will not give total power drop and then just get better again.

Same thing on my recent road trip. I hit a heavy batch of rain close to an hour of straight down pour! I had to slow down to 60 MPH and afterwards I had the same problem you have described. It had me worried, because it felt like a boost/fuel cut, or a really bad hick-up on heavy acceleration. I took it easy and finished my trip. Let the car dry out for a day and the problem never came back. Vortech Supercharged with around 35,000 miles on the clock.

Hmmmmm. Belt gets wet and slips maybe?

That is exactly what happened to me!

I thought about that too. I asked Jackson Racing and they said that was not possible, there was way too much tension on the belt for it to slip even if it was wet. The engine did not look wet to me.

Pat

Ya, it seemed too easy but needed to remove it as a variable.

Check your MAF, when this happened to me it was the MAF, it was drenched.. Water caused a short and car went full limp mode, once it was dry, car was fine

Sent from my A0001 using Tapatalk

This does seem possible, although that is a long way for the water/moisture to go. It would have to make it through the supercharger and inter-cooler piping to get to the maf.

No way to know after it dries out.

Pat

what? no. your MAF is directly after your airbox. you're thinking MAP which is on top of your intake manifold

No. He's boosted. Still, it was my thinking when I asked about the CAI. There's no place for the water to pool so it would get sucked through.

Jesus. Everyone boosted should be tuned on speed density. It works fantastic on these cars.

Update: answer found!

I believe I figured out what the issue was.I actually have de-modded my car and have sold it since then. I did not realize this until I was boxing up my supercharger when I sold it. I saw water stains inside the pipe going from the intercooler to the engine, like water had gotten that far and was running back down.

The car acted as thought it would if the MAF was wet, and I guess the maf was wet. It seems unlikely that the water would have gone though the air filter, super charger, intercooler and all of the pipe to get to the maf, but that is what I now believe happened.

When you sold it was it still having that issue? Did it go away after you removed the supercharger?

It only did it that one time, never before or after in the rain. I think it was because I drove in the rain for an extended period of time.

Pat

I'm with you dude, I was hooning my car in a parking lot with a friend and had TC off fully using the simple Hold for 30 seconds and it was so much more difficult keeping a stable drift in a circle in the dry and I kept feeling pulling on one side with no lights or anything warning that the TC is kicking. Do the pedal dance and my friend who knows nothing about cars immediately says that felt way better and I could hold the slide in a circle for much much longer. Also driving home afterward felt less of a nuisance with things kicking in on certain streets