loss of power/ bucking in rain

[fasteddy]

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.

[JS + BRZ]

TC kicking in?

[CSG Mike]

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.

[strat61caster]

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.

[Ultramaroon]

Originally Posted by JS + BRZ

TC kicking in?

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.

[humfrz]

Originally Posted by fasteddy

I had a strange incident today. .................... 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.

Open to any ideas

Thanks!

Pat

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


humfrz

[humfrz]

Originally Posted by Ultramaroon

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.

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


humfrz

[Ultramaroon]

Originally Posted by humfrz

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


humfrz

I'm tellin' ya it's fuckin' BULLSHIT, man!

[fasteddy]

Originally Posted by JS + BRZ

TC kicking in?

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.

Originally Posted by Ultramaroon

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.

That sounds familiar.

Originally Posted by humfrz

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


humfrz

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

[humfrz]

Originally Posted by fasteddy

............. 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.


I think I will throw a set of plugs in to be safe, ...........

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

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

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


humfrz

[Ultramaroon]

Originally Posted by fasteddy

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.

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?

[Ultramaroon]

Originally Posted by humfrz

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

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

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


humfrz

Hey, I remember 6 Volts & big fat cables.

[fasteddy]

Originally Posted by humfrz

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

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

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


humfrz

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

Originally Posted by Ultramaroon

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?

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

[humfrz]

Originally Posted by Ultramaroon

Hey, I remember 6 Volts & big fat cables.

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 ……

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