Engine Running Rough

[traveler999]

I have a 1999 Windsor, ISC330. I working on the air systems, so I would start the engine to build up pressure then repair some leaks and then restart the engine to build up pressure again and the engine ran smoothly. After many times I cranked it up it sounded like a thrashing machine. This was overnight. If you give it fuel it does rev up and still runs rough, but after awhile it goes into the limp home mode and ignores the accelerator pedal. When it does this it stays at idle but it levels out and runs smooth. Because it runs smooth there I don't believe it's a fuel problem or injector problem or Caps. Could it be the ECM?

[Skip426]

Are you able to retrieve codes from the ECM ?

Were you working near the engine on the air leak ?
Any chance you could have disturbed a fuel line or the primer pump , and let air into the fuel system ?

EDIT: Any chance that with the repeated start ups , you ran the chassis battery voltage low?

First thing would be to disconnect the chassis batteries and fully charge them , restart and see if the condition still exists.

[RustyTools]

When I was chasing down a bunch of air-leaks and a defective air-valve recently, I didn't feel comfortable doing the same start-stop/over-and-over routine with the engine to keep the coach aired-up, so I bought an inexpensive 'pancake-style' air compressor and plumbed it into the air lines.

Worked great, and it saved wear and tear on $$$$ engine components. It wasn't powerful enough to reach full pressure, but was plenty to find my leaks, etc.

[jacwjames]

Originally Posted by Skip426

Are you able to retrieve codes from the ECM ?

Were you working near the engine on the air leak ?
Any chance you could have disturbed a fuel line or the primer pump , and let air into the fuel system ?

EDIT: Any chance that with the repeated start ups , you ran the chassis battery voltage low?

First thing would be to disconnect the chassis batteries and fully charge them , restart and see if the condition still exists.

All good advise.


How full was the fuel tank, when was the last time the fuel filters were changed. Do you treat your fuel for algae, how long has the rig been sitting.



But to really know what is going on is to get fault codes. I get codes off my Silverleaf VMSpc display. Without the codes you are just guessing what might be going on and just through parts at it might do more harm then good.



Last time I had a code I had stopped to fill up with diesel, it was a cold rainy day so left the engine running. While filling up the rig started to run really rough, never had done that before. I didn't have a CEL but when I check the diagnostics on the Silverleaf it showed I had a fault code, something to do with fuel pressure. But it cleared up and never happened again.

[RobRoy]

As stated earlier you should have a scanner most anything less would most likely be a guess.


If it were a LD truck or a car I would scan for codes then see if I could isolate it to a specific cylinder and proceed from there and read the scanner data related to the fault code and proceed from there.

Im not a HD truck guy, that I had a friend that had a HD Freightliner Moho conversion I cant remember the diesel engine size but when he pulled in and pitted next to me he was in limp mode / Low power and that thing was banging and shaking and I though the engine was coming unglued.


He dumped his trailer and the rig was then towed to the local Freight liner dealer and they diagnosed and fix was a failed fuel injector.

To this day I cant believe how poorly it ran and the noise's it made.


I know I'm of no help but just throwing it out there because it may not and probably is not as big of a disaster as you might think.

Now IIRC the cost of the diagnosis and fuel injector repair was pretty dern pricey.

Good Luck &
Happy Hunting