GXP bogging down/idling rough

[PaulyGXP]

This is the 2nd time this has happened. I think it is occurring after I wash the car, as that is when it has happened both times. The car will start and run normal, but under acceleration it is bogging down and at WOT it feels like the car is running at half power. The SES light began blinking under WOT and now the SES light is on to stay. Any ideas before I have the codes pulled tomorrow?

[00Beast]

Wiring and/or coil. I know the coils have been problematic for some members.

[PaulyGXP]

No SES light today. It seems to be running just fine so I don't know. It has to be something electrical I would think. I somewhat agree that it may be a COP. It's just weird that it has done this twice now in the past few times I've washed the car, but never before in the previous 2 years. I didn't do the engine bay, and I washed it in the driveway with a sponge and the hose. It's not like I was blasting water into the engine bay but who knows. I think I can still get a code pulled if the SES isn't on by checking the history.

[CMNTMXR57]

Typically, a coil or plug causing an issue will do/have the tendencies of TWO things;

1) Consistent, readily noticable, timed repetitive missses or misfiring
2) Misses will trigger a P0300 and/or P030x code

If you're saying that you did not get any DTC's, and it was just a matter of driveability more than anything, to me that tells me something is getting wet along a hood line, or even a sensor (MAF?), is getting water somewhere. MAF's don't work well trying to measure water... Your PCM is in that front corner. If it's not sealed properly in the box (or is no longer in the box due to CAI), is water getting into it's connections. Is water getting into the intake plumbing? At the back of the engine, is the main harness that runs just under the cowl, if water is getting down there, perhaps shorting something out temporarily, etc...

But an ignition miss is typically something consistent, and timed repetitiveness.

[PaulyGXP]

I'll have to look into that a bit more next time I wash it to see what gets wet when I wash the exterior. I have washed the engine bay repeatedly and never had trouble. It shouldn't be MAF or air intake, but I'll check that too. When it was having issues it sounded like fuel was just getting dumped, not burned. Today it runs normal, I think.

[CMNTMXR57]

Is the harness that controls the injectors getting wet? I believe it's all in that large master harness on the backside of the engine...

[PaulyGXP]

It could be... Now I have to wash the car again to find out!

[Arrowhead]

I used to have a VW that was "paralyzed" by wetness. This stuff worked every time ! Maybe using it in a process of elimination might work for you ?

http://www.amazon.com/Gunk-M1306-Wire-D ... B00200CBD2

[PaulyGXP]

While I was at work the other day it rained really hard for a few hours. When I went to leave the car ran fine, then when I began to accelerate it started coughing. It's definitely not firing on one or more cylinders as it sounds horrible and bogs way down. The SES light flashed at me until I quite accelerating and set the cruise. The SES light was just on then. It ran like crap for the rest of the day. Next day, ran fine. WTF!!!!!!!!

[PaulyGXP]

I don't understand how all of a sudden this thing hates water. I have been washing the engine bay for almost 2 years with soap and water, and now even if it rains the darn thing is throwing fits. Drives me nuts.

[CMNTMXR57]

If everything is ok (meaning all weather connectors check out, and all things are properly sealed), it isn't the first time I've seen stuff like this. My aunt had a 70's Monza that if the humidity was higher than 50%, much less actual rain, just cancel all plans to go anywhere because it wasn't running. :shrug:

Heck, I posted up once, my GXP, in one particular grocery store parking lot, would just shut off. No rhyme, no reason, whether it was today, 6 months ago, or 6 months in the future, if I went into that parking lot, it would shut off. Every *dang* time too...