'85 454 in a ForeTravel

[edifanob]

My brother has a ForeTravel that he's been having some trouble with.

He's recently had the motor replaced (1 yr ago) with an 1985, 454 Chevy engine and it has a Holly Double-Pumper. He'll be driving along just fine and the motor loses power and will hardly run. It appears he can let it set for a bit then start it again and that cycle starts over, but maybe it won’t go as far the second time.

He's replaced the fuel filters (the inline and carb filters) and has converted to an electric fuel pump. The problem persists.

Any help would be appreciated.

THANKS!

 

[RRitenour]

'85 454 in a ForeTravel

It's the fuel pump relay failing under heated conditions. the relay was strategically placed by GM engineering on the top the engine so it will break down under heat. Thanks GM!
RR

 

[Poppa]

'85 454 in a ForeTravel

Looking at the problem from the fuel side, with all things considered, it may be vapor lock if when they replaced they relocated a fuel line next to a heat source.

You said it looses power, does it back fire or just acts like someone cut of the ignition :question:


Makes a difference on where you want to look for the problem.

Poppa

 

[Ed H.]

'85 454 in a ForeTravel

I would echo Poppa's post...I've heard of ignition coils getting "weak" and not producing spark when they're warm, but let them cool off, and they work like new(er). I don't know, but electronic ignition modules may do the same when getting ready to go too.

 

[can-do]

'85 454 in a ForeTravel

I have a '85 454 Chevy in my Fleetwood and the fuel pump arrangement was an electric fuel pump located back by the fuel tank and a mechanical one located on the engine. Are you sure there isn't one located by the fuel tanks because if it goes bad it acts as a restriction to fuel flow in a very short period of time of driving but if you check fuel pressure at an idle everything seems fine. It's a volume flow problem verses delivery pressure. Take a look especially if your fuel tank is located in the rear of your rig, I'd bet this to be your problem. Have been there before and it wasn't a fun experience to troubleshoot on the shoulder of a major hwy during rush hour.


Charles

 

[Kirk]

'85 454 in a ForeTravel

My 87, 454 had the exact same problem as is mentioned by cando and it gave the very symptom listed here. The electric fuel pump was mounted just outside of the tank, and on the frame rail next to it. The pump was pressure sensitive and it would maintain a positive pressure at the inlet to the engine mounted mechanical fuel pump. It was there to prevent vapor lock and was quite common in those days on chassis with the 454. When it began to fail it was intermittant and seemed to fail to restart as fuel pressure would drop when under load. Once there was a new pump in it's place, the old 454 went back to it's good running self!