Engine mising at full throttle aand going up hill

[Steve Albert]

I have a 2006 Beaver Monterey with  a 400 cat  when I give it full throttle or go up hill it sounds like it is missing or cutting out not running smooth

[Bill Lampkin]

Change both fuel filters, then see what happens. Others here are the engine experts, but I think they would start by suggesting the same.

[David T. Richelderfer]

1) Change the filters and 2) look for air leaks into the fuel supply.

[Eric Maclean Co-Admin]

Steve
As the others have said replace your filters a miss fire up load at speed is usually a fuel starvation problem is the fuel system can't keep up with the fuel demand.
1) check and or replace fuel filters
2) look for water in your fuel separator
3) check fuel rail pressure possible low pressure at the rail ( defective fuel pressure regulator) rear of cylinder head

Beyond that you will require cat software ( scan tool) to diagnose injector operation. For defective injector or low HEUI pressure
Both of which may set a code ( check engine lamp)

Odds are your problem is either bad fuel filters or an air leak on the suction side of the fuel system.

Go luck and let us know what you find
Eric

[Steve Albert]

I had the fuel filters replaced. I will take it some were and have it checked out

[Steve Huber]

Steve,
Could be low boost pressure caused by a sticking waste gate. Check out the C9 article in Ask Dave.
Steve

[Joel Ashley]

Fuel starvation (wrong or dirty filters usually) is the likely cause, as others diagnose, but as I recall there is a fuel delivery modification recommended (see Ask Dave) for our era C9’s.  I’ve never had an issue, so haven’t explored the modification myself, but you may need to do so.

[Dave Atherton]

Gentleman, the problem missing or jerking under load we have had very good response in troubleshooting the problem. If we. Could
get the blink codes or engine codes with Cat ET we should have what called active event code of 102-2 boost pressure signal erratic or
102-7 boost pressure not responding  part number cat 161-1704 ( part number may be updated possible ). Next sensor that would be
108-4 atmosphere pressure sensor part number cat 161-1703, both these sensor would allow the missing or jerking under load. Yes we
have good answers along with fuel system and lack of fuel but before going deep into the problem money wise I would suggest go with
Boost pressure sensor first. Dave Atherton Retired Cat  mechanic

[Stan Simpson]

Steve,
We've had our coach for 8 years. In that time we have experienced your symptoms three times. Each time we got a 'check engine' light. We were traveling every time, so we took the coach to the nearest CAT dealer who could check the codes. Each time it was the boost sensor. Dave Atherton is correct. The part number each time was 161-1704. The last time was in Idaho Falls, ID, July 2, 2019, work done by Western States CAT. $503.94, part and labor.