Engine Trouble 2006 W-22 8.1

[Painter3066]

Left for Florida last night and about a hour into the trip engine started to backfire and hesitated while going up hills. Ran fine on flat road going back home but engine missed a lot. Coach is 10 years old and I never have changed spark plugs or wires. I have 43000 miles on it any thoughts?

[Painter3066]

Thanks for the replies will take it in next week for plugs and wires. The fuel filter was recently changed.

[rgatijnet1]

Spark plug wires and it could also be water that was ingested in to the air intake and has soaked the air cleaner paper element. Did you drive in the rain?
The spark plug wires are a fairly common problem and a good set of silicone wires, WITH the heat shields, is a good solution.
The fuel filter can be accessed from underneath and it is within a foot of the fuel tank along the frame rail. Yours uses a special filter that is hard to find and expensive. The do make an adapter that will replace the special filter and allow you to use one that is readily available at most auto part stores.

[donfrump]

enblethen wrote:
Engine may have coil packs and not wires. Some of them fail and should set code if on input side.
I would first replace the fuel filter.

yes but they still have a spark wire from coil to sparkplug and fuel filter wont cause engine misfire but a bad fuel injector will;
usually if a injector misfires it will make the check engine lite flash continually

[enblethen]

Engine may have coil packs and not wires. Some of them fail and should set code if on input side.
I would first replace the fuel filter.

[Trackrig]

My brother has to change his plug wires every 3 - 4 years due to the heat generated in that front engine compartment. If that's not your problem, it will be shortly. You should get them changed.

Bill

[donfrump]

Dick A wrote:
This could also be a sign of the fuel pump failing. However, check the fuel filter first.

anythings possible but 99% of the time a plugged filter or weak/failing pump wont cause the engine to miss and backfire under load lack of fuel usually causes engine die outs and major hesitation
based on my experiences

[Dick_A]

This could also be a sign of the fuel pump failing. However, check the fuel filter first.

[donfrump]

Painter3066 wrote:
Left for Florida last night and about a hour into the trip engine started to backfire and hesitated while going up hills. Ran fine on flat road going back home but engine missed a lot. Coach is 10 years old and I never have changed spark plugs or wires. I have 43000 miles on it any thoughts?

backfiring while underload(going up hill etc) sounds exactly like bad plug wires and or plugs for sure