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  #1  
Old 03-29-2005, 05:31 PM
LarrySpankowitz LarrySpankowitz is offline
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Do I really need to clean out my "fuel injectors"?

The lube place that changes my oil always tells me I need this, but I'm not so convinced about it.

1. Is this really necessary, and what would it accomplish?
2. Can this be done without professional equipment / knowledge -- perhaps with a storebought product?
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  #2  
Old 03-29-2005, 05:45 PM
don't ask don't ask is offline
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My mechanic who I trust completely (sometimes he will do a small job for nothing or talk me out of expensive work in favour of a cheaper substitute) has recommended it twice. Both times the cars in question ran better after. He doesn't like storebought products. As he explains, "If it loosens the deposits on your injectors first of all it loosens all the crap in the fuel tank."
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  #3  
Old 03-29-2005, 05:51 PM
LarrySpankowitz LarrySpankowitz is offline
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I should also mention that

1) the last time I cleaned the injectors was in 2002, and
2) since then, the car has gone less than 5000 miles.

do I still need it?
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  #4  
Old 03-29-2005, 07:29 PM
kanicbird kanicbird is offline
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Quote:
I should also mention that

1) the last time I cleaned the injectors was in 2002, and
2) since then, the car has gone less than 5000 miles.

do I still need it?
Since you posted this in 2005, I can assume that 1+2=you drive that car about 1600 miles per year. If this is true, this is car abuse and expect the car to develope problems all around from underuse. Gas will breakdown if not use up and it seems more likely that you will have resins all over your fuel system, so adding a FI cleaner to the tank is likely to cause more harm then good. I would say that while it might not be absolutly needed, it could prevent future problems.

Now if you ment 50,000 miles then I would go for the stuff you add to the tank.
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  #5  
Old 03-29-2005, 09:12 PM
LarrySpankowitz LarrySpankowitz is offline
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is it really "car abuse"? I use it at least once a week, but I don't really drive long distance.
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  #6  
Old 03-30-2005, 01:22 AM
DarrenS DarrenS is offline
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I asked almost exactly the same question:

http://boards.straightdope.com/sdmb/...d.php?t=293791
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  #7  
Old 03-30-2005, 03:56 AM
engineer_comp_geek engineer_comp_geek is online now
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Quote:
Originally Posted by LarrySpankowitz
is it really "car abuse"? I use it at least once a week, but I don't really drive long distance.
Once a week is probably ok, but you need to make sure that the car is driven long enough that it fully heats up. Water vapor can condense into water and build up inside of the engine and exhaust. Under normal conditions it just gets heated back up into water vapor and expelled, but if you don't run the car long enough it won't be, and you'll end up with rust problems as a result. I've heard it is fairly common for exhaust systems to completely rust out on underused cars like yours.
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  #8  
Old 03-30-2005, 04:15 AM
don't ask don't ask is offline
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So say I lost my licence for 3 months. What would I have to do to keep the car in good nick? Would just running it for 10 minutes once a week be enough?
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  #9  
Old 03-30-2005, 07:47 AM
Balthisar Balthisar is offline
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Quote:
Originally Posted by don't ask
So say I lost my licence for 3 months. What would I have to do to keep the car in good nick? Would just running it for 10 minutes once a week be enough?
When I was stationed in Germany I left my cars (on supports) for two years. Did a couple of common-sense things, but nothing out of the ordinary, and didn't have any problems that I didn't cause in starting her up two years later (hint: don't leave the parking brake activated for two years on a rear-drum system).

Now, I routinely leave my car untouched for two months at a time. It's just sitting in the garage. There's a slight vibration on the steering wheel at low speed now, though, so I don't know if it's because of the tires sitting for a long time (out of balance?), or if something's about to fall apart. I'll have it looked at on the next trip home.
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  #10  
Old 03-30-2005, 08:45 AM
Gary T Gary T is offline
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See my post in the thread linked by DarrenS.

I can't see where 5,000 miles of use could even come close to building up significant deposits that would be addressed by a fuel injection cleaning. 30,000 miles is a more typical interval.

You can't duplicate a properly done flush without dedicated equipment. It runs special solvents through the system for a period of time. Nevertheless, it is often worthwhile to add a bottle of a good fuel system cleaner into the tank occasionally. For normal usage (10K-15K miles/year), every 3 or 4 months is adequate. The brand I recommend is Techron. I have seen it clear up some minor problems, and have no doubt it is helpful for preventative maintenance. I don't understand the concerns expressed about putting cleaner in the tank. I've never heard of that causing a problem.
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  #11  
Old 03-30-2005, 10:37 AM
Rick Rick is online now
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To echo Gary T's comments in the linked thread, if you have a mechanic that you can trust this is a non issue.
Injectors can and do get plugged, but nearly as often as iffy lube would have you believe.
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  #12  
Old 03-30-2005, 02:24 PM
Jake4 Jake4 is offline
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When did fuel injectors become common? Do all cars have them?
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  #13  
Old 03-30-2005, 03:08 PM
Gary T Gary T is offline
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Quote:
Originally Posted by Jake4
When did fuel injectors become common? Do all cars have them?
This isn't exact, but it should be pretty close:

We started seeing modern fuel injection in the '70s, it became more common in the '80s, and all* cars had it by the '90s.
____
*The one exception being one model of 1990 Subaru which still had a carburetor.
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  #14  
Old 03-30-2005, 03:17 PM
Rick Rick is online now
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In reverse order, yes all cars being built now have fuel injectors, and have for many years now. Not sure when the last carb was installed on a new car, probably in the early 90's.
Fuel injection was rare before 1969 (before then it was only done for performance, think Porsche 911, 300SL Gullwing Mercedes) Starting in 1969 FI was used for emission control. My own company stopped bringing cars with carbs into California in 1970-71, and was fully FI in all 50 states by 1973. As emission controls got tighter, better controls were needed for metering fuel. A carb is just not up to the precision needed to meet modern emission requirements. Basically a carb is just a toilet bowl that flushes a very imprecise amount of fuel down the drain into the engine.
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