Fuel injector cleaners?

[1schoir]

Brian:

As I said before, very level-headed analysis.

Jake Raby has also confirmed the increased presence of gasoline and other contaminants as the engine gets more and more miles put on it, based on his own test mules. This is one of the reasons why he believes that oil change intervals of 15K are simply too high.

IMHO the 15K mile oil change intervals are a marketing ploy by Porsche to tout their "low maintenance requirements". YMMV. ;)

Regards, Maurice.

[ssp996]

On the issue of gunk getting into the system because of low fuel, I would challenge that if gunk was there it would be sucked up anyways no matter how full or empty the tank is. My reasoning being that gunk particles are heavier than fuel and would precipitate to the bottom anyways. The fuel is picked-up from the bottom ( I assume) unless it is skimmed from the surface, (which I doubt). So, empty or not, any gunk or whatever would exist on the bottom. I tend to agree with Loren, that the initial poster's issue is more of re-trainning of the computer than anything else, maybe air in the lines, or a blown pump due to overheating. Not an engineer, just an opinionated sob!

[C4C_Leon]

On the issue of gunk getting into the system because of low fuel, I would challenge that if gunk was there it would be sucked up anyways no matter how full or empty the tank is. My reasoning being that gunk particles are heavier than fuel and would precipitate to the bottom anyways. The fuel is picked-up from the bottom ( I assume) unless it is skimmed from the surface, (which I doubt). So, empty or not, any gunk or whatever would exist on the bottom. I tend to agree with Loren, that the initial poster's issue is more of re-trainning of the computer than anything else, maybe air in the lines, or a blown pump due to overheating. Not an engineer, just an opinionated sob!

Normally I would also agree with Loren, but in this case, after I disconnected the battery (for about 8 hours) it was still very rough and sounded like it was choking. It died about 6 or 7 times on me while going to the mechanic.

The Indie I took the car to said I had "very dirty" fuel lines and injectors.

He cleaned the system with injection cleaner, and I also had him clean my K&N air filter and do an oil change since he had the car.

He says it's running perfectly now, and I'll pick it up tomorrow.

[rrspikemarty]

...

The Indie I took the car to said I had "very dirty" fuel lines and injectors.

He cleaned the system with injection cleaner....

Is that an easy/inexpensive DIY ? Any special tools required? Sounds like a fairly innocuous remedy that could be followed by anyone that suffers similar symptoms as yours, before taking car to repair shop ... just musing.

[1999Porsche911]

It's all about tank design. In most cases, the fuel pickup in new cars is NOT at the the lowest point in the tank. This portion of the tank is reserved for sediment (which is minimal due to better filtering of today's fuel delivery systems). More and more tank designs are also engineered to reduce or eliminate disturbance of sediment at the lowest part of the tank when filling it with fuel. All pumps also have a screen to eliminate intoduction of large debris into the system and most, if not all, smaller particles will be stopped by the fuel filter. The cleaning of your injectors is not to remove debris that is stuck in them but to reduce any varnish that has accumulated in them. This problem has all been elminated for people who use an ethenol based fuel. In most cases, using a fuel additive to clean injectors is nothing more than a "feel good" approach only and serves no real purpose.

It is still a good idea not to let your tank get too empty because of floating debris as well as your electric fuel pump is cooled by it's submersion in the gas.