2003 V6 bogs when it rains

[bartmann7167]

Whenever it rains or drivining in heavy fog/wet air my engine is sluggish on occation when I accelerate. When I start it it takes 3-5 seconds to start on these type of mornings. Usually it fires right up. Any ideas where to start?

[johnaauld]

Originally Posted by bartmann7167

Whenever it rains or drivining in heavy fog/wet air my engine is sluggish on occation when I accelerate. When I start it it takes 3-5 seconds to start on these type of mornings. Usually it fires right up. Any ideas where to start?

Do you have the 2.7? The CPS(crankshaft position sensor) is a known problem with this engine. The wiring insulation falls off in time and the wires can short out causing all kinds of symptoms. When it rains, it seems to make it worse in shorting out. If you have the 2.7, you should change out the CPS in any case as a preventative measure even if it is not causing your current problem. If it goes bad enough it can cause the engine to not work at all and you will be stranded.

[bartmann7167]

yes its a 2.7. Is this difficult to replace?

[sbr711]

Crank position sensor can be faulty, easy part to replace, typical on shelf stocking item at any Hyundai or Kia dealer (whoever closer).

Last tune, how old is the plug wires and plugs, typical replacement is 60,000 mile

Fuel pressure regulator random leak too

[bartmann7167]

I changed the plugs and wires not too long ago but it might need to be completed again. Id like to try the CPS. Where is this located?

[johnaauld]

Originally Posted by bartmann7167

I changed the plugs and wires not too long ago but it might need to be completed again. Id like to try the CPS. Where is this located?

It's around $75 at the dealer, cheaper online. I'd go OEM but that's me. It's located right above the starter. I did mine on my santa fe(same engine) without ramps, but I'm sure you would need ramps. There is a shield on the starter that needs to come off first. Two bolts and a nut(if memory serves), rotate the shield 90 degrees and pull it off toward the driver side. Here, a lot of people pull out the starter to get easier access. I didn't, but it is hard to see what you are doing if you don't. The single 10MM bolt holding the CPS on is very tight to get a socket on- so use a 1/4 inch ratchet set so that the walls are very narrow on the socket. This is a worthwhile preventative measure no matter what else.

[MyKids04Sonata]

The MAF sensor and the coil packs are also affected by damp weather..
The coils can leak high voltage through their sides (can be seen at night in a dimly lit area)...
Have you checked for OBDII codes? Advance and AutoZone will pull them for free.. Even "if" the check engine light is not on code can/will be stored. This can help with diagnosis..
And I agree the CPS (crank sensor) is a real DOG and should at least be checked for bare wires.
Dave

[11SonataScott]

A spray bottle of water can help diagnose this problem. Pop the hood in a very dark area and with the engine idling, spray a fine mist on the spark plug wires, and other componets mentioned above.
Sometimes you get a lightning show to go along with your stumbling engine. It can be very revealing.