95 Coachmen -Miss in 460 FI Eng

[Tony Cureton]

My Engine has an constant miss at Times - other times it runs great- I have also noticed a different sound at the Air breather intake - When it runs good the the air intake is a smooth Purr - when it misses the air intake is a roar--any advice would be appreciated. TONY

[Wanabee FTer]

Hi Tony and
Your F53 MH should have OBDI emissions system. Certain types of engine miss-fires can be detected by the pcm and will set a check engine light on your dash. If the light is on, either find a tech to diagnose or you can buy a cheap code tester to retrieve fault codes. A fault code will help you diagnose the concern by telling you what system is malfunctioning.
If no codes are present and concern is intermittent, I would first check for any vacuum leaks. Look at the engine vacuum hoses, but also check the connections on the other end of the vacuum lines. Sometimes they crack or fall off.
If no leaks are found I would pull the plugs out to inspect the electrode color.
Check against a spark plug chart to help diagnose.

[justimagination]

Tony...........Wecome to a great forum. I would lean toward a FUEL problem. Gas Engines regardless what make or model must have IGNITION/FUEL/AIR to run properly." Erratic " problems such as yours (IMHO) are caused from lack of fuel, either from clogged fuel filter or faulty fuel pump. First, I would replace the fuel filter, which is on the left inside of the frame rail close to the transmission area. NAPA carries them and it does require a special tool to remove the old one. Ignition or vaccum problems do not fix themselves part of the time, and then are OK. Good luck, Happy trails & travel safe.
David G.

[Wanabee FTer]

Another thing that may be causing an intermittent miss-fire is water or fuel contamination. This is fairly common after a rain storm. During a rain storm some gas stations do not drain properly and allow rain water to collect in their tanks. To check this, remove the fuel filter and drain the fuel into a clear cup or bottle, a soda bottle works fine. Then look at the fuel. If it has contamination it will separate from the fuel just like oil and vinegar does with salad dressing.

[SteveLevin]

I tend to agree you look at air/fuel/spark as the likely culprits. So be sure to look at your plug wires as well in case one has been damaged.

Steve

[Tony Cureton]

Thanks for the advice --Tony Cureton

[Wanabee FTer]

Thanks for posting back Tony,
Please get back with us when you figure out what's wrong.

[leadman]

Not unusual to have an injector coil to work intermittently. This should set a code though so that is the place to start. Also if this has the individual ignition coils for each cylinder they are prone to having "carbon tracking" down the side of the coil tower. This is usually a visible dark trail from where the spark plug wire plugs in the coil down the side. Sometimes if dark enough the spark can be seen on the side.

[bunique]

Hi tony have same problem with 95 pace arrow w/460 motor. they say fuel pump problem. having pump changed in a few weeks, will let you know.

[Wanabee FTer]

Yes, I forgot to mention possible fuel pump problem and that makes sense with the OP's original concern. Since a fuel pump replacement is somewhat difficult to do on this model, I would suggest a fuel pressure test first. You can even drive the HM around with the doghouse removed to monitor the fuel pump pressure while driving. When the problem occurs the FP pressure should not get much lower then 30 psi.
Harbor freight sells a nice fuel pump tester very cheap.

[WejaZ28]

Just a thought........ These engines a notorious for running extremely hot around number 4 cylinder(passenger side rear). I had similar problem with plug wire boots melting/cracking and causing a miss. This happened most often with hot engine and after stopping at a light and getting back up to speed.

Weja

[Tony Cureton]

Quote:

Originally Posted by justimagination Tony...........Wecome to a great forum. I would lean toward a FUEL problem. Gas Engines regardless what make or model must have IGNITION/FUEL/AIR to run properly." Erratic " problems such as yours (IMHO) are caused from lack of fuel, either from clogged fuel filter or faulty fuel pump. First, I would replace the fuel filter, which is on the left inside of the frame rail close to the transmission area. NAPA carries them and it does require a special tool to remove the old one. Ignition or vaccum problems do not fix themselves part of the time, and then are OK. Good luck, Happy trails & travel safe. David G.

Thanks for your time and advice- Will let you know how it comes out --Tony

[Tony Cureton]

Quote:

Originally Posted by bunique Hi tony have same problem with 95 pace arrow w/460 motor. they say fuel pump problem. having pump changed in a few weeks, will let you know.

Thanks -- I have the same feeling that its my fuel pump -- Will let you know how I make out---Tony

[Tony Cureton]

Quote:

Originally Posted by justimagination Tony...........Wecome to a great forum. I would lean toward a FUEL problem. Gas Engines regardless what make or model must have IGNITION/FUEL/AIR to run properly." Erratic " problems such as yours (IMHO) are caused from lack of fuel, either from clogged fuel filter or faulty fuel pump. First, I would replace the fuel filter, which is on the left inside of the frame rail close to the transmission area. NAPA carries them and it does require a special tool to remove the old one. Ignition or vaccum problems do not fix themselves part of the time, and then are OK. Good luck, Happy trails & travel safe. David G.

David Thanks for the Advice - I have already changed the filter-which was extremely plugged - have not checked the pump-will let you know what I find Thanks Tony Cureton