Horsepower Problems

[ColumbiaH20]

Ok, so I have a 35' Southwind with a workhorse chassis. Up until now, I have had stellar performance from my engine..

Now it's lacking horsepower. The engine runs and idles fine, doesn't get hot, and all the gauges are reading at their correct levels. However, when I take off from a dead stop, the engine acts as if it's in 3rd gear (and it isn't) and seems like the engine is "sputtering". Climbing a grade is a joke. 25 mph at best.

I have checked the fuel filter and replaced it, and am using a fuel additive. The air filter is new, and I only have 17,000 miles - so I'm ruling out plugs.

Any thoughts - suggestions?

-Carl

[bdpreece]

Burnt or shorted plug wires.

[Clifftall]

Could be a bad tank of gas. Possible water or sometimes a high amount of ethanol.

[Gary RVRoamer]

No "check engine' light, indicating a stored code from the ECM? Usually the ECM sees the problem, or at least the results of it.

[DAN L]

Quote:

Originally Posted by ColumbiaH20 Ok, so I have a 35' Southwind with a workhorse chassis. Up until now, I have had stellar performance from my engine.. Now it's lacking horsepower. The engine runs and idles fine, doesn't get hot, and all the gauges are reading at their correct levels. However, when I take off from a dead stop, the engine acts as if it's in 3rd gear (and it isn't) and seems like the engine is "sputtering". Climbing a grade is a joke. 25 mph at best. I have checked the fuel filter and replaced it, and am using a fuel additive. The air filter is new, and I only have 17,000 miles - so I'm ruling out plugs. Any thoughts - suggestions? -Carl

i don't know what kind of fuel additive you are using.
try some seafoam fuel additive. i just had this problem in my car soon after i filled the gas tank and seafoam cured it in about 35 miles. i surmise that there was water in the tank that was intermittently blocking the in tank fuel filter, the only fuel filter my car has.
the problem got progressively worse shortly after i filled the tank and it wouldn't run over 2500 rpm (and that was rough) before using a can of seafoam.
if that had not fixed my problem, next i was going to disconnect a gas line under the hood and blow low pressure air into it with the gas cap removed.

[millsrv]

There are three very important things to do next. 1. Check the fuel pressure at the injector manifold. 2. Check for stored codes & misfire data (even if there is no check engine light). 3. Connect a vacuum gauge to manifold vacuum and check for a exhaust restriction. All of these things should be done by a qualified technician.
Based on your description I would look long and hard for a misfire under load. I do speak from experience having been in the auto repair business for the last 36 years.
Best of luck to you.

[ebkstk]

I just went thru what sounds like the same problem. idles fine,no power on hills,doesn't want to down shift at lower speeds. i have 5000 miles on 2005 coachmen with workhorse w22 8.1 motor.i replace the wires they were burnt and had a cracked plug runs great again.check the workhorse forum lots of threads about bad wires.

[bldrbob]

Look at the engine running at nite. If the wires are shorting out you should be able to see sparks.
BOB

[tpmcn]

Just a thought, When my 36' Georgie Boy did this it turned out to be the rear brakes hanging up. If you have not checked you might want to sit the coach on a level surface and take your foot off the brake in 1st gear, if it doesn't pull foreward at idle then I would suspect a hang up.

[Batman_777]

There are a least 2 dozen things this could be. Fuel supply, timing, injectors, firing, exhaust, valves, fuel quality (water in fuel), turbo (if any), emissions, torque converter (while in motion shudder), etc etc

Sputtering sounds like the motor basics, but you said it sounds fine until you start moving.

You'll need to start at the most basics and do a problem elimination to narrow things down.

[ColumbiaH20]

Thanks for all of the input.

I took a long hard look over the intake system. (I agree with the ignition symptomes ie, wires. I'll check those too.)

I found that the air cleaner attachment to the mass airflow sensor was slightly loose. I reconnected it and it drove better.

I'll road test it and see if the prob's solved and repost.

Thanks!

-Carl

[txdutt]

just changed out the plugs & wires on my Sunrise, none of the old plug wires were burnt like I've read about on some of the WH forums but man those plugs were nasty with deposits...coach has 35k miles--put 2 bottles of the concentrated Gumout fuel system cleaner and took it on it's first roadtrip over Labor day weekend--surprised on how much smoother it ran

[max49]

I'd start with # 5 or #7 SP wires. Driver side, 2 rear plugs.