| Author | Message | ||
     Naustin |
I have the fuel injectors out of the bike while replacing intake seals. Is it possible to determine by visual inspection if they are clean or dirty? I read about the leak test in the service manual, but I forgot to perform the test prior to tearing the bike down. They look clean to me. But, i wonder if there is anything specific I can inspect while they are off the bike. Thanks} | ||
| Blake |
Dirt is, well, dirty. I wouldn't know anything else to look for. Do you have a service manual? It probably describes some kind of inspection for the injectors. | ||
| Rocketman |
There should be no signs of carbon deposits along its length and certainly not on the tip. A clean injector will look like aged metal as in perhaps slightly tarnished from heat. Of course, you cannot see inside the injector but a microscopic piece of debris could be lodged in there but it's unlikely given the debris could only really enter the fuel system from 'dirty' petrol, or contaminating the fuel tank at fill up. There are some excellent fuel injector cleaners on the market that you simply add to the fuel. I've never used them personally but Saab's have excellent quality components in their f.i systems so seldom give trouble in that department. That said, I can think of one 2002 9-5 Aero 2.3 HOT that has been plagued by an intermittent running fault. One minute the car goes like a rocket, because they are bloody fast, then the next minute it's like someone shut the boost down halfway. The main dealer has done an awful lot of work on this car under warranty. I'll spare you the details but trust me they've done everything you'd expect and more to solve this problem, including have a tech from HQ in Sweden look over it. Well they've pulled their hair out for nearly a year and still the owner is reporting the car has this intermittent problem (which the tech's involved have experienced too), so the other week a bright spark suggested running fuel injector cleaner through the system, and you know what, I wouldn't believe it myself but the car is flying now as it should with no sign of the intermittent fault at all. Any other time I'd have declared fuel injector cleaner as close to snake oil. Rocket | ||
| Naustin |
Blake Service manual does not specify an inspection procedure. It specifies a test to see if it is stuck open and leaking, and there is a flow chart that suggests replacing them given certain symptoms - but nothing about a visual inspection. Rocket Crazy story on that 9-5! I did run a bottle of Techron through my bike, and while it didn't result in such pronounced improvements, it did seem to make a little bit of a difference. That said, visual inspection shows no carbon deposits, and the metal just looks a little aged as you say. Which is good, because I already reinstalled them.  Nick | ||
| Naustin |
Oh - also (may as well post it in this thread) When I had the intake manifold out, I was looking in the port at the intake valve and man was that carbon'd up. It had piles of carbon on it. This bike sat at a dealer for 2 years. I wonder if it was subjected to the - start - run for 10 minutes, turn off for another week - Procedure... What would cause this? All that oil from the breather system, maybe?? Should I run Techron through it with every tank of gas for a year or what? | ||
| Blake |
Carbon on the intake side of the intake valve indicates the presence of excessive oil, possibly via leaking valve guide seal, possibly via excessive blow-by and the crankcase breather. | ||
| Naustin |
Did you mean: escessive oil...from excessive blow-by, OR from the Breather system OR excessive oil...From the breather system BECAUSE OF excessive blow by? Both intake valves showed carbon build up, so unless both valve guides are shot, I'd say this is due to oil from the breather system. I know the old tubers are known for having issues with the breather system and several aftermarket companies make parts to control the amount of oil entering the intake tract - is it possible that this is just normal and that Crossroads breather bridge dealie will solve the problem? (Message edited by naustin on October 13, 2006) | ||
| Blake |
Blow-by is exhausted via the crankcase breather system, so your second interpretation is the correct one.  Valve guides may be fine. The seals may be leaking. I don't know anything about the Crossroads breather bridge dealio. A catch can might help. Severe carbon deposits on the intake valves is not normal though, so I'd be looking to address the root cause of that. | ||
| Rocketman |
I have no valve guide oil seals and there are no issues. End of the day, an engine that requires valve guide oil seals is usually one that can trap oil in the cavity that houses the valve train, which is why when these types of engines suffer from worn seals they tend to smoke first thing when they've stood for a while. Once warmed up it shouldn't be much of a problem unless a good flow of oil passes over the valve train cavity. I'd suspect in Buells case if there's an issue of carbon build up on the intake it's likely caused by venting the breather in the intake tract. Rocket | ||
| Bluzm2 |
Nick, The solution to the "junk" in the intake is to get rid of the stock breather system and route the breathers to a catch can. The best solution is to install XB rocker covers and block off the stock breather bolts. I'll post a picture tonight for you of the "engine in progress". Brad | ||
| Naustin |
I might have exaggerated the carbon build up. I've only ever seen clean new valves, never really looked down an intake port at an "in service" valve before. It was quite black, but beyond that I'd need to take a better look I guess. The chunks of carbon may have been a figment of my cynical and pessimistic imagination. I read the thread where Blake and Jose go back and forth over the definition of blow-by for about 8 pages... LOL.... I'm not saying Blake was wrong, or Jose was right, but I think Jose was on to something in his argument that when both pistons move down, the crankcase becomes pressurized and that stops the oil from being able to move down the push rod tubes - thus sending more of it out the breather system. But, I don't want to re-kindle any horse beating sessions. I'm planning on a setup like Jackbequick did, except I'll probably buy a jazz catch can or something similar rather than DIY a filter like he did. There's another winter project to go with my front isolator replacement. I'm not going to worry about compression or valve seals or or Blow-by. The bike has 8,000 miles on it. I'm going to assume its fine and forget about it something a little more verifiable goes wrong. Brad, I'm looking forward to those pictures. Are you using the standard fittings and hoses or are you going with the Devenator unit? (EDIT) Oh - you mean you're going to XB rocker covers?! Cool! (Message edited by naustin on October 13, 2006) | ||
| Blake |
The one-way umbrella valves allow the exhausting of positive crankcase pressure and prevent the ingress of any air. So after the initial downstroke of the pistons, the crankcase is essentially evacuated. Without blow-by there is no crankcase pressurization. If you ever get a chance take note of the paltry amount of exhaust, nowhere near 1200cc worth, that typically exits the crankcase breather while the engine is running. That should convince you of the situation. Interestingly you may be surprised to find that blowby is more prevalent for low throttle openings. This is because the rings do not seal as well in the low combustion pressure environment. Crank the throttle open and combustion pressure increases a bunch and ring seal is improved thus reducing blowby. (Message edited by blake on October 13, 2006) |
