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RVcollector · 09-12-2014, 04:23 PM

After owning way to many RVs of every kind, my last one was an 84 southwind 26' class A with only 26,000 miles on it. Obviously sat too long, took it on long trip in august, limped it home on 6 cylinders. Just bought a 2000 Damon 28' class A with 7.4 chevy on workhorse chassis. Driving it home after purchase, very hot day, 70 mph, about 65 miles, 3 miles from home it lost power, would go 5mph floored, popping and backfiring. I was able to get home at 5mph, hoping I wasnt damaging it more. Previous owner claims it never happened (yeah right), doesnt show it in any work receipts anywhere. Today it fires up, sounds good, but Im afraid to pull out of driveway. read some threads on here about hot fuel pump, vapor lock, hot fuel lines, adding seafoam, keeping more than half tank(just put in enough for a little over half before driving home)..

Is it possible its the fuel filter, or vacuum lines? Any ideas where to start. Definitely doesnt sound like the 84 with 2 cylinders gone, but feels same when driving. Very depressing.

**JohnRR** · 09-12-2014, 04:28 PM

You'll get more answers in this forum than in Introductions.

M&EM · 09-12-2014, 04:50 PM

Sounds like mine did this summer after a long haul in very hot weather(>100). Came off free way. Popped and stuttered 2 miles to a camp ground. Fuel filter and pump relay checked OK. No fuel pressure-- bad fuel pump was cause --- at 90000 miles.

If yours sat around, could be filter or pump or both. Easy test to

get fuel pressure tested.

RVcollector · 09-12-2014, 07:54 PM

What is the optimum fuel pressure on this engine?
2000 7.4 chevy workhorse chassis

M&EM · 09-12-2014, 08:25 PM

probably 55 -60 psi if its MPI

RVcollector · 09-13-2014, 06:44 PM

the fuel tests out at 50 psi, but thats after its been sitting for a couple days. if it was vaporlock or hot pump, that wont tell me anything. I havent driven it yet, am afraid to.and I need to fix whatever it is before it happens again. lost on next move

M&EM · 09-13-2014, 11:19 PM

I assume your fuel pressure test was with engine running??
Replace fuel filter AND check old filter for blockage or resistance to flow... Check fuel tank cap for proper action( @auto zone --etc)..

terry735001 · 09-14-2014, 11:59 AM

i am sure this is really right ....Previous owner claims it never happened (yeah right)

it could have set for some time as well or he did not drive it the same or as hard and never showed up

its some thing getting hot or fuel system ?

M&EM · 09-14-2014, 01:29 PM

Might also check/clean MAF sensor in the air intake using appropriate cleaner. Although this malfunction would probably set off an engine code.

Also look for loose or partially attached air inlet plumbing to the throttle body assembly especially where it is supported on the upper radiator shroud.

RVcollector · 09-15-2014, 08:18 AM

Im pretty sure the motorhome has been sitting for a while, other than changing locations of where she put it up for sale. She is 81 years old and probably never drove it fast and hard. I put in $100 gas and drove 75 mph for an hour on hot day and after cresting a very steep hill is when the trouble started. We put the fuel pressure gauge on and drove it around for a half hour up hills yesterday, 55 # and drops to 35# on hills briefly, but keeps power, did not duplicate problem. Where is fuel filter located on the workhorse? Nothing seems to overheat, and the engine is running very cool according to gauges. Ill look for loose plumbing at throttle. Thank you all for input, I really appreciate it and accept any ideas you may have. Thanks,

RVcollector · 09-15-2014, 09:05 AM

The mechanic now tells me it did have an 02 sensor code, I would think that is pretty important?? Im assuming replacing the intake sensor would be a step in the right direction?

Full.Monte · 09-18-2014, 09:59 PM

If there's one thing i've learned, it's "Never assume you have only one problem". On my p32, the fuel filter is on the inside of the frame rail, passenger side forward of the rear wheels.

tomwalt · 09-24-2014, 06:49 PM

I'd drive it on short trips - might have been some bad gas or varnish in the fuel line that got loose and caused your 3 miles of scare.
Reset the error code and watch for a re-occurring code. If the O2 sensor has really failed, your power will be decreased and fuel economy will be real bad.
Won't hurt to replace the fuel filter, but you are throwing parts at it without knowing what the problem really. Bottom line is you won't know if you have a real problem until you drive it some more.

George Schweikle · 09-25-2014, 06:32 AM

Yep. Some call this the secret fuel filter. It can be tucked inside a frame rail bend so you can't really see it until you look carefully. On our '99 7.4, a partially clogged fuel filter caused the "Check engine" light to intermittently come on. On our old carburated '82 427, a clogged fuel filter would cause the engine to stutter when climbing a grade.

Quote:

Originally Posted by Full.Monte

If there's one thing i've learned, it's "Never assume you have only one problem". On my p32, the fuel filter is on the inside of the frame rail, passenger side forward of the rear wheels.