Fuel cap replacement. I was reading my 50,000 mile service book and in says replace fuel cap city dusty driving conditions. Does anyone think that may be the cause of so many injector problems? Cause and effect bad cap dirt enters tank filters clogged injectors spent? I believe that during develoment of this engine the fuel was very clean but in real world applications it is not? Could it :smashfrea :smashfrea be that simple?

My guess is the filter(s) stop/prevent debris getting to the injectors ~ its a truck and shouldn't require a laboratory environment ~

I think the cap is a vacuum-breaking function only. It doesn't have any internal filtration capability that I'm aware of. The recommendation is based upon loss of the ability to effectively break vacuum, or suck unfiltered air. Good news is that a replacement costs about $6.

i think the injector failures were cracks on the injectors

I think the cap is a vacuum-breaking function only. It doesn't have any internal filtration capability that I'm aware of. The recommendation is based upon loss of the ability to effectively break vacuum, or suck unfiltered air. Good news is that a replacement costs about $6.
:exactly: :exactly: :exactly:

Idahofox

Ok so why does the good book say to replace it only in dust/city driving? There is more to this. I have read that the main cause for injector failure is dirty tips. Not poor manufacting of the injectors. Also if dirt was not an issue why do people spend so much on additional filtration devices ie Nictane ect. ?

Dusty/city conditions would lead to more likely contamination and failure of the cap internal venting system. Injectors fail on design issues in the early models and erosion of internals caused by contaminates in the fuel on all models. People spend so much on additional filtration devices to avoid fuel contamination and erosion of injector internals. You seem to be asking a lot of rhetorical questions. I have a Kennedy Diesel Mega Fuel Filter mounted post-oem. I cannot, however, install a "clean room" and a glove bag over my filler neck while fueling at he truck stop in Texas in a dust storm. The amount of dirt intrusion into a closed fuel cap has got to be mininscule in comparison to the amount of crap introduced by the fuel supply system at the tanks and pumps. The cap only acts to prevent a vacuum developing that might collapse the polyethylene tank. There's little danger of it, because even though the fuel is being drawn and comsumed by the engine there is also a good bit if recirculation. Do you have a point here, or just want to continue to restate the obvious?

I may have wandered down a conspericy theory road. Thanks for the clarfication.:)

It is more important to change your fuel filter at regular service intervals I would think!

It is a mere cautionary maintenance item. Since the fuel cap is essential in the pressurization of the fuel system and if left open will cause the SES light to trip and could cause the vehicle to not run or run very rough. The idea to change it is simply to keep you from having your SES light come on and taking to the dealer and then them chasing down a gremlin since it couldn't be the fuel cap...... it's tight......my wife had to replace the one on her Venture at 35K sucks to tow the rig to the dealer cause it won't run to later figure out it was a faulty gas cap $10.43.....my .02

my injectors were plugged with carbon, not dirty fuel.