Question about fuel injectors

[printman]

I have a 2000 1200LT with 12,000 miles my last check my dealer did he told me that the rough idle in my engine was cause by a bad fuel injector. so he said if you replace one might as well replace all. can the fuel injector be replacement by me. i'm handy with tools or does it take special tools and equipment to do this work. if the 12,000 miles check cost me $800.00 this other job might be higher. thanks for any imput...... printman

[c00k1e]

I take it you have tried injector cleaner?

[Dean_BMW]

My experiences are based on my '03 model. Yes, the fuel injectors are pretty easy to replace.... just remove the plastic and remove the left side fan and remove the bolts from the fuel rail and pop them all up and out.

If you have not tried fuel injector cleaner, I would do so. I like BG's 44K... costs about 30 bucks per can... but it works. I would put it in, run it down the road for about 30 minutes and then let it set over night and then go a trip the next day. Make sure you adjust how much you put in for the volume of the tank. It's pretty powerful stuff. You will have to buy it from a repair shop. It's not sold retail. Here in OK, repair shops everywhere use it. Not sure about other areas.

[Dean_BMW]

Actually... just looked online.. you can buy BG's stuff on Ebay and everywhere else... much cheaper than the last time I bought any.

[munson]

I have a 2000 1200LT with 12,000 miles my last check my dealer did he told me that the rough idle in my engine was cause by a bad fuel injector. so he said if you replace one might as well replace all. can the fuel injector be replacement by me. i'm handy with tools or does it take special tools and equipment to do this work. if the 12,000 miles check cost me $800.00 this other job might be higher. thanks for any imput...... printman
How does run at speed? What kind of mileage do you get? Mine idles roughly, too, but once the rpm is up it runs great.

[info]

Speaking of FI cleaners, doesn't BMW recommend Techron??
I wouldn't use much BTW.

[bwingate]

I have a 2000 1200LT with 12,000 miles my last check my dealer did he told me that the rough idle in my engine was cause by a bad fuel injector. so he said if you replace one might as well replace all. can the fuel injector be replacement by me. i'm handy with tools or does it take special tools and equipment to do this work. if the 12,000 miles check cost me $800.00 this other job might be higher. thanks for any imput...... printman

I've got to call shenanigans on this one. He's telling you to fix all of them because he's hoping that's what the problem is. Its not like its a $5 spark plug that's a consumable - fuel injectors aren't cheap, $75-100 I'm guessing, and they aren't exactly wear items either.

Bruce.

[Sunshine]

I'd take them out and get them flowed before I'd do anything if you think the injectors are bad. You can also ohm check the windings to see if they are still good. I'd be suprised if they went bad already. If you have a local garage that can flow them, they can also sonic clean if they are clogged, install new screens, and also put new O-rings on them. After working on automotive and M/C stuff for quite a while, I haven't seen any cleaners that really work other than taking them off completely.

[was]

I have a 2000 1200LT with 12,000 miles my last check my dealer did he told me that the rough idle in my engine was cause by a bad fuel injector. so he said if you replace one might as well replace all. can the fuel injector be replacement by me. i'm handy with tools or does it take special tools and equipment to do this work. if the 12,000 miles check cost me $800.00 this other job might be higher. thanks for any imput...... printman

If a service manager or tech suggested this to me he would never see me again. But I would ask some pointed questions before I left: which fuel injector is bad? and how did you determine that that particular injector is bad? exactly what is wrong with the injector? gosh, can't answer any of those questions, huh? so what would be the rationale for replacing the three good injectors on a bike with 12K? if my front tire needed replacement but my back tire was fine, would you recommend replacing the back one as well? oh, I see, it's because once you are in there to replace one you might as well replace them all at the same time? is that what you do with valve buckets? if one is out of spec you replace them all? if the fuel filter needs replacement do you replace the fuel pump just because you are in there? what does your boss think about recommendations like this? and what is your boss's name and telephone number?

[printman]

I know it sounds funny replacing all injectors, right now when I start the bike I have to stand over it cause the engine wants to turn off, my last 12k check was a hole in my pocket, here in miami there is not a lot of BMW dealers, yjis one is next to the palmetto expressway on 36 street so im kind of shell shock with this problem. the dealer said the engine running rough was a bad injector but he wont tell me whick one. so here I stand waiting. ohhh one more thing. 3 weeks after I pick it up the brake sensor are blinking

[Tat_n_Telle]

If the bike seems like it's running on 3 cylinders at idle, it may be a bad injector - BUT - a bad injector does not magically start working correctly off idle. How does the bike perform at higher throttle openings? You may have a throttle body synch issue. At any rate, if one injector is bad, I see no reason to replace all four of them. It sounds more like "I think there may be a bad injector, but I don't want to take the time to figure out which one it is" or, worse yet "I don't know how to properly diagnose which one it is, so I'll just use the 'shotgun' approach and replace all of them".

If they are going to be in there looking for the bad injector, all they have to do is disconnect each one electrically while the bike is running. A good injector will have a dramatic change, while the bad injector won't make anything worse, since it's not working anyway.

[dshealey]

You got several good replies, I agree with all of them. Well, not so much the one that said no injector cleaners are any good.

There is one more thing you can do, and that is use a long thin screwdriver as a "stethescope" (or buy a mechanics stethescope from you local auto supply store). With the engine idling, put the end of the screwdriver on each injector with your ear against the end of the handle. You can hear the injector clicking, and if one sounds different, is missing, or not clicking at all, then that could be the culprit.

But, there are other things that can cause rough idle, such as spark plugs, spark plug wires, vacuum leaks on the throttle bodies, etc. When it is idling, does the idle speed vary up and down a lot? If so, that is almost guaranteed to be a vacuum leak, most likely one of the little lines to the throttle bodies is off.

When you pull the side fairing off, pull the cover over the spark plug wires and check them all for chafing. If they are arranged badly, one can chafe against something and wear partially through the insulation, then it will spark through. You could pull all the plug wires away from anything metallic, and each other as much as possible, then restart the engine to see if it smoothes out any.

Regarding injector cleaners: I agree that the ones you buy over the counter and put in the fuel tank are mostly a waste of money, as the concentration is so light it won't do much. However, there are injector cleaner units on the market ( I made my own) that are used to pressurize the injector rail with highly concentrated cleaner. These will do a pretty good job on injectors that are in good condition, with non clogged screens, but just a little dirty on the pintle/spray cap. These are small tanks that you put the cleaner in with gasoline at about a 15% ratio, then use compressed air to pressurize the tank to the correct injection pressure for the vehicle, disconnect the vehicle's fuel pump, then run the engine on that.

Your engine has such low mileage on it, that I doubt injector issues. That low mileage on a 2000 bike means it sat for long periods. It could be varnish buildup in the fuel system if no fuel additive for long storage was used when it sat. Have the plugs been changed as recommended at 12K? If so, one wire may not have been put back on correctly. If the bike was worked on by the dealer, I would check all the plug wires, and the vacuum connections.

In any event, do not pay any attention to what that "mechanic" says ever again. Replacing 4 injectors when 1 "may" be bad is totally ridiculous.

There are injector shops all around the country that will disassemble, clean, and flow test them. Just Google "fuel injector rebuild" About $25 each.

[Sunshine]

Regarding injector cleaners: I agree that the ones you buy over the counter and put in the fuel tank are mostly a waste of money, as the concentration is so light it won't do much. However, there are injector cleaner units on the market ( I made my own) that are used to pressurize the injector rail with highly concentrated cleaner.

You are correct. The stuff you put into your tank is like buying baking soda and pouring it right down your sink. It's a waste of money. I just did not list the above option because 99% of the people could not go that route to clean their injectors.

[Dean_BMW]

Let me tell you a fuel injector cleaner story.

Had a friend that had a 4 cylinder car that would barely run. She had been told that the problem was fuel injectors (don't know where she went to get that advice).

Anyway, I poured a can of 44K in the gas tank and just let it idle... about 45 minutes later, I noticed that is was running slightly better.... so I let it continue to idle. After about an hour and half of idling, I noticed it was a little better yet. At this point, I took it out on the road and ran it at pretty high RPM and drove it back home. 90% of the roughness was gone, but not all, so I let it idle another hour and then took it out on the road and ran the RPM's up. When I got back to the house... it was idling as smooth as silk. Of course, that was several years ago... before gas was 3 bucks a gallon. At current prices, might be better to just start it, let it run for a few minutes and then wait a few hours and start it again.

I have since used BG's 44K in several different vehicles and in most cases, have had good results. However, none of them started out as bad as the vehicle I described above.

For those that are interested, BG products does make a system that will pressurize the fuel rail. As I remember, you have to pinch off the return line with a pinch off tool, pressurize the fuel rail with their system and then let the engine run off of their solution. I borrowed one one time and used it, but I don't own one because, frankly, it's a bit pricey for a do-it-yourselfer.

[BMB02]

I have almost the same experience some time ago but I did not make the replacement for my BMW fuel injector (http://www.advancebmwparts.com/bmw-fuel-injectors.html)...I'm not that handy with those things, I let a mechanic do the work for me. I believe if I did it myself it will end up with such a mess.. :rolleyes:

[Morley]

If the bike seems like it's running on 3 cylinders at idle, it may be a bad injector - BUT - a bad injector does not magically start working correctly off idle.
Actually the first symptom of an injector that is clogging up is an unstable idle, caused by an improper spray pattern. The improper spray pattern impacts engine performance mostly at idle where the engine is turning slowly, letting in little air and the fuel isn't atomized well to begin with.
At higher RPM's it is much harder to detect a partially plugged injector. However, if left alone, it will get to the point where it will "miss" at the higher RPM's, but by then you would really feel like there is a dead cylinder at idle.

Try sending the injectors to Rich at Cruzinperformance (Google it). He can clean them and flow check/match them for about $80 or less.

[Tat_n_Telle]

Actually the first symptom of an injector that is clogging up is an unstable idle, caused by an improper spray pattern. The improper spray pattern impacts engine performance mostly at idle where the engine is turning slowly, letting in little air and the fuel isn't atomized well to begin with.
At higher RPM's it is much harder to detect a partially plugged injector. However, if left alone, it will get to the point where it will "miss" at the higher RPM's, but by then you would really feel like there is a dead cylinder at idle.

Try sending the injectors to Rich at Cruzinperformance (Google it). He can clean them and flow check/match them for about $80 or less.

Should have clarified my statement. I was referring to an electrically open or shorted injector.