Loss of power when driving

[init6]

I have a 2005 pace arrow with a workhorse chassis that seems to have lost a lot of power. The the point that it can barely make it up a hill or get up to 65 mph on the interstate. This comes after pulling it out of long term storage. I haven’t driven it in a while but have had someone starting it for me once a month and adding new fuel and stabil when needed while I was serving overseas.

Any thoughts on what to look for? It sounds like it is running fine for the most part aside for a sputter every now and then when I put the gas pedal down all the way. At some point today while going up a hill, the check engine light came on.

Thanks in advance

[Grit_dog]

Fuel pressure is easy to check and good to eliminate as the problem, but electric fuel pumps usually are good or don't work. Not ususally an in between.

[init6]

Just an update…. Have tried a new tank of gas. Ran all the old out first. Replaced the air filter and vacuumed out some deteriorated foam in there with a shop van. Replaced the mass airflow sensor with a new one and still the same issue.

I’m wondering if it isn’t fuel pump or fuel filter related.

[wnjj]

Our 2005 8.1L lost a mass airflow sensor a couple of years ago. It set the check engine light when pulling hills. The ECU tests the MAF when under heavy throttle so that’s when it sets the code. Never really seemed to be down on power but I replaced it and the MAP sensor at the same time since both are involved in the test and need to agree. Easy to replace either of them, DIY.

[frankwp]

Just this weekend, while towing up to our camping vacation, the truck would drop down to what felt like about half power. Kinda butt clenching when your going up a steep pass. I took it in yesterday & is was the mass airflow sensor.

[wa8yxm]

Corkey05 wrote:
Make sure some critter hasn't stuffed the intake hose with nesting material. check it all the way back to, and including the intake filter. It's a quick easy way to check one off the list, and possibly find the problem.

An excellent suggestion Corkey.

Also I once left one of my favorite MI places to head south for the winter and noticed a "Strange Sound" (Ok not strange I knew exactly what it was... Misfire) My Wife could not hear a thing.

Rodents lunched on the ignition primary (low voltage) wires. Some solder, Tape and 2 new plugs and full power once again.

There are many sensors. Hoses and wires.. Some of them you won't hear anything wrong.... Just no power.

A OBD-II adapter and phone application like TORQUE will read or even reset in some cases the error codes.. >This can be helpful. .. Or Cryptic.. Depending

I once had my car start, suddenly act up.. This was OBD-1 I read the code and called the mechanic who told me the code class. (not the specific) I thanked him, Popped the hood. Hooked the sensor back up (Yup I when he said "emissions" I knew what it was) and on the road again in about the time it takes to type this last paragraph. And I type fast.

[wolfe10]

Signature says W-24, so GM 8.1 liter gasoline engine.

[naturist]

OP didn’t specify diesel or gas, but either is also susceptible to marginally clogging fuel filter.

[init6]

Good tips, I’ll start looking into those. Thanks again

[eHoefler]

I would look at getting a full tank of fresh gas first. Sounds like you may have a tank of flat gas that has degraded over time.

[DrewE]

Since the check engine light came on, I'd think the first order of business would be to see what code was set. That may help with diagnosing the problem.

One thing to check is the mass airflow sensor, if your engine has one. They sometimes get dirty and cause stumbling upon application of the throttle (among other symptoms). A general lack of power can be caused by a dirty engine air filter or some other obstruction in the air inlet; with modern computerized engines, those things don't tend to cause other obvious effects--they just have the same net effect as limiting the throttle to not open fully.

[Corkey05]

Make sure some critter hasn't stuffed the intake hose with nesting material. check it all the way back to, and including the intake filter. It's a quick easy way to check one off the list, and possibly find the problem.