1997 Winnabego Brave with chevy 454

[tom_mary731]

I am having a problem and have spent several $1000`s of dollars and no one can figure it out I even had to tow it 200 miles home I have a 31 foot brave with a chevy 454 in it problem is I was on a trip 680 miles into it with no problems stopped in Indiana got gas and then it started it ran fine then lost all power slowing me down to 10-15 mph changed the fuel filter and mass air flow sensor it idles great starts right up you don`t even have to step on the gas pedal rev it up does great put it in gear and your done it spits and spudders and chokes you out with the rich smelling fumes you can not go over 10-15 mph anyone else ever had this problem or no what can be the problem I only have 34,000 miles on the rv thanks for any help I am ready to get back to rv`ing

[tom_mary731]

well update it is fixed after all that it was both catalytic converters were clogged up thanks everyone

[tom_mary731]

we had the fuel pressure checked it is fine goes up with increase Throttle have only found one fuel filter took it off changed it to being with has me stumped cause it starts with just turning the key and idles smooth even with increase in throttle but put it in gear and done the mechanic now thinks it`s a vacuum leak he is checking that also says maybe a lobe on the cam is bad I have a hard time believing that with the way it idles wanting him to check the throttle body sensor the bill keeps going up hoping he finds it soon or I will have a nice RV for sale lol I will keep you posted what we find out thanks for the feedback

[MEXICOWANDERER]

Test fuel pressure yourself using a good gauge and stout fuel line connector hose. I've caught too many garage mechanics using dartboards and guessing and this makes what little hair I have left stand up on end.

Stage one. Check fuel pressure. If it drops, check voltage at pump. If it drops as well, check amperage. If amperage raises while delivery falls, it's the pump. If voltage drops along with amperage, trace it backwards to the relay. Check incoming and outgoing voltages at the relay. Then check, if necessary, the relay -coil- control voltage. Don't forget to check the relay grounding circuit for the relay coil operation.

This will tell you without a doubt yes/no that a problem does, or does not exist in the fuel pump electrical power and control circuits.

[Happy_Prospecto]

An old boss had an El Camino once with the same symptoms as yours and we found a bad catalytic converter.

[SkiingSixPack]

I had pretty much the same problem on an older 454, carbureted. I had the fuel pump replaced and ran new wiring.... Problem was solved... I actually had the wiring changed first and it got better but then came back. Best as my mechanic could tell it was a bad fuel pump, temporarily helped by new wiring....

[D_E_Bishop]

I had similar problems with the Bounder and it turned out it was a relay. The carbureted models have a relay that controls the in-tank pump, mine was bad intermittently. I would as suggested either have the pump output pressure tested or check it yourself.

I went to a chain type auto parts store and bought enough fuel hose to reach to the tank from the dash. I bought a low pressure fuel pressure gauge (you will need a high pressure gauge) and hooked it up through an unused connection of the pressure/flow regulator. Started up great, idled for about 25-30 minutes while I adjusted pressure regulator and cleaned up tools. Started for the gate of the storage yard and suddenly, poof no pressure. Finally found the relay causing the problem, In my case the relay is multifunctional and no longer made. Followed suggestion found on this forum and spliced in a substitute relay, no more problem.

I ran the pressure test several times to see if there was any other problem. A mechanic who decided from what he knew, that the pump was good, but he checked the pressure, once, and had pressure so shut the engine off, I kept it on to see if any specific driving pattern caused the drop. Long story short, if the problem is present upon start up, a short test is probably good. If the problem occurs after warmup and is random you need to keep the gauge hooked up and drive until the problem resurfaces.

[RJsfishin]

Thousands of $s and no fuel pressure check.
Starts good, idles good, but no power, perfect example of low fuel pressure.

A fuel filter will first give trouble at high speed WOT on a mountain grade.

[John_Burke]

Check your catalytic convertor.

[tatest]

My first choice for "starts, idles, runs, won't take a load" is a clogged fuel filter. You took care of that, so failing fuel pump would be my next choice, but rich fumes throws me off. A fuel leak anywhere between pump at the tank and injectors could cause a problem and produce fumes.

Do you know whether you have the 454 with throttle body injection, or the Vortec 7400 with multiport injection? A 1997 motorhome straddles the transition year, and each of the two engine series has its own problems. The big change was intake manifolds and fuel injection technology.

[jplante4]

Recent thread on this issue. Bad ignition module in distributor disables the fuel pump. Happened on my gasser.

[Nick-B]

Have the fuel system pressure checked. At idle and under load. My bet would be on a failing fuel pump as well.

[wildtoad]

I had a similar problem in a 1988 Winnie I had for a short time. Running fine, filled with gas then ran like crud. Thought I got a bad tank of gas. Wasn't. I too had replaced the fuel filters (there were two) , plugs, wires, etc. What the guy at the shop finally determined was a bad fuel pump. Replaced it an ran fine.