Pace Arrow Backfires!

As you all know, occasionally I turn to one of my FOG's (Friends of Gary) for input to a reader's question. This month, I invited Jim Brightly, former Technical Editor of FMC Magazine and motorhome chassis expert, to chip in with a response to Art who has an engine question. Here's Ed's question and Jim's response:

I have a 1997 Ford Pace Arrow with a 450 V-8 engine. The question I have is, why is it backfiring? It does this when I start going up the hill plus it seems to slow down. I put it down to low and it gradually picks up speed. But then on level ground, it seems okay, but on upgrades, it is a harder go. While sitting still, the engine and the RPMs are great and it does not backfire. Only when I rev up the engine or take off or when hitting the passing gear does it backfire. Can you help? Art E., (Oceanside, CA)

Jim's Response: 

Art, I'm of the opinion your motorhome needs a complete tune-up and all new filters (air, fuel) installed. Additionally, it may need a fuel tank cleaning. The reason it’s backfiring is because it’s running too lean. That is usually caused by fuel starvation and/or a timing issue. Contaminated fuel or a dirty fuel container can also cause starvation issues with symptoms similar to what you are experiencing. So I'd replace all the filters, have the engine tuned and perhaps the fuel inspected for tank contamination. Once the engine is tuned and the timing set and you're feeding it with clean fuel through new filters, you should definitely see an improvement. Hope this helps! Jim

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