Community Forums

JRJ · 03-13-2016, 02:29 PM

After the unit is driven about an hour the engine light comes on and the unit loses power in the gas pedal. You can feel the unit starting to jerk and it won't go over 25-30 mph. It surges finally and starts to go again. They say it is not the transmission. It's been in the shop a couple of times on a machine to find something. Nothing!
It does it after you drive it a while. Have check everything.
The gauges are always normal but the rpms at that time are higher than they should be prior to the surge and then they go down after it seems to go back to normal.
Anyone have anything happening or has happened to them? I own a 2005 Tiffin Phaeton 40ft.
It is maintenanced year round as needed. Any help would be appreciated.
Other than this my coach is perfect.

Skip426 · 03-13-2016, 03:50 PM

Welcome to iRV2.

You've given info on your coach , but not on the engine . Cummins I presume , but the engine type ISC , ISL , HP rating, and info on if equipped with an, engine brake or exhaust brake; will help other members give you ideas.
Mileage ? and was the checking done at a Cummins shop ?

skypilot_1 · 03-15-2016, 08:33 PM

First things first. have the fuel filters been changed, recently, like now. With engine temp in normal operating range. With trans in neutral, parking brake on, press accelerator pedal to floor slowly. If you can't get steady smooth max RPM and engine making huge amount of white smoke, almost like stream, you are fuel restricted. Check lines, left pump and filters. We had algae in fuel and would clog filters in 500 miles. Maybe something else, but you need to eliminate the easy stuff first. good luck.

JohnBoyToo · 03-15-2016, 10:53 PM

Ditto - fuel filters !!!

JRJ · 03-16-2016, 07:38 AM

Quote:

Originally Posted by Skip426

Welcome to iRV2.

You've given info on your coach , but not on the engine . Cummins I presume , but the engine type ISC , ISL , HP rating, and info on if equipped with an, engine brake or exhaust brake; will help other members give you ideas.
Mileage ? and was the checking done at a Cummins shop ?

Engine is a Cat 350 and exhaust brake.

JRJ · 03-16-2016, 07:50 AM

Quote:

Originally Posted by skypilot_1

First things first. have the fuel filters been changed, recently, like now. With engine temp in normal operating range. With trans in neutral, parking brake on, press accelerator pedal to floor slowly. If you can't get steady smooth max RPM and engine making huge amount of white smoke, almost like stream, you are fuel restricted. Check lines, left pump and filters. We had algae in fuel and would clog filters in 500 miles. Maybe something else, but you need to eliminate the easy stuff first. good luck.

Trying all I did do that and we made it to our destination with no further problems so we will hope for the best on our way home. Thank you for your help. If it happens again I will make sure I follow these steps. This has been a huge problem and I keep the coach maintained year round on all. Has been in the shop for this as well but no codes show at the time of being in shop. Fuel filters and maintenance recently done as well.
Thanks again

JRJ · 03-16-2016, 07:53 AM

Quote:

Originally Posted by Skip426

Welcome to iRV2.

You've given info on your coach , but not on the engine . Cummins I presume , but the engine type ISC , ISL , HP rating, and info on if equipped with an, engine brake or exhaust brake; will help other members give you ideas.
Mileage ? and was the checking done at a Cummins shop ?

Mileage just turn 50,000
2005 Tiffin Phaeton
350 Cat
Allison Trans

skypilot_1 · 03-16-2016, 10:30 PM

If you have experienced lack of engine power, fluctuating rpm and check engine light, you need to have your fuel system check for fugas/algae. The problem with canister fuel filters is you can't see how clogged they are without cutting them open. Our Cummins had the above faults for 100 miles, down to 45 mph at full throttle. Then magically run fine for 1000 miles. Till it won't run higher then 5 mpg.
Found the filters clogged with black squally algae.
Fix was changing filters often and treatment with Biobor JF, which is a poison to kill the algea and add Star Tron to clear the filters when running. And never storage coach with less then FULL fuel tank.
Spent hundreds of dollars at Cummins and FL shops trying to find the cause of problem. Best way to check this is to run engine at max rpm to see what you get, as outlined in previous post here. You may have a totally different fault for these symptoms, Bad fuel is the last thing most diesel shops investigate, and I think thats an economic thing with some shops...cha ching !