Need some FI advice, plz

[Alpha Crow]

I mentioned earlier that I had a problem with my BB (99, 13k miles, PCII, Micron Slips). Wouldn't start sometimes (new batt installed, still nothing), good connections everywhere, ran very poorly at low idle.

Anyway, I finally broke down and took it to the shop. They are unsure thus far of exactly what it is, but are saying that one or two of my cylinders are not running. They say that one or two of the cylinders/injectors are cold on temp testing.

The FI light never came on and never gave me a warning light. That plus when you crank it up, all cylinders are hitting just fine. I can tell that some cylinders are out when it warms up, but why would they work initially and then stop? Timing?

Also, after talking with the mechanic, I'm thinking this may all trace back to a bad tank of gas. My buddy on a Harley had a slight problem after topping off with me, but his carb'd machine had much less problems.

Anyone have a similar problem? I'd like to know what I'm looking at, I already had to deal with the mechanic wanting to do a lot of minor things that I already tested/cleaned/changed out. In my opinion, kind of like a taxi driver taking you home via the scenic route for extra $$$. I just changed the sparks after the problem, have maybe 50 miles on them and he wants to change them again ("just to be sure"... for about $65). Any experience or knowledge would be helpful in dealing with him, he seems fairly honest, but trying to take a costly route to getting to the issue.

Thanks!

[XXTi]

Just a guess, but have you verified that you have spark to all cylinders? A bad coil could kill two cylinders after it warms up.

[JasonW]

Personally I would get my bike back from that shop and try a few things to fix it myself. If he's wanting to change the plugs again "just to be sure", then I'd say he might be milking you.

I'm no FI expert, but you can verify for yourself if 2 of the cylinders are not firing by simply feeling the warmth off of the header (downpipe). Obviously, don't grab a hot pipe, but you'll be able to tell if one or more cylinders is cold. The blackbird coil fires 2 cylinders per coil, so if it's a pair that are cold you may want to compare with what coil fires which pair.

Do you have a service manual? If not, get one.

If you suspect bad gas and possibly two clogged injectors, first try swapping out the gas and running some SeaFoam through it to see if it clears up. If not, you can get the offending injectors cleaned for cheaper than replacement.

I'd try some of these simple things before shelling out the cash for someone to experiment on your bike. If you are not mechanically inclined whatsoever and have the money to pay someone then that's understandable, but no one will take care of your bike the way you will.

You said that you changed the plugs yourself? Did you double check everything before reasembly? That's always a good place to start. Also, you may try disconnecting the PC to rule that out as well, ya never know.

Good luck, and let us know what you find out.

[Alpha Crow]

Well, the problem started apparently after the tank of gas or whatever is causing the issue. It's very hard to tell, since it runs great and suddenly takes a turn for the worse for unknown reasons.

Order of events: Problem began slightly on start up. Did some tests, battery was a BIT low (about 5 years old). Cleaned up connections, replaced the battery. Problem did not go away, but was alleviated somewhat. Ok, starts getting worse, idle is starting to chug and start up is sometimes good sometimes bad. I performed an oil change, cleaned the K&N filter and airbox, changed sparks, examined spark boots and wires. Problem did not show up as fast as usual, but eventually it did.

The old spark plugs were in great condition, but installed new ones, properly gapped and torqued properly with a torque wrench. Seated the boots all the way (much finger pain in the process... can I get an Amen?). Removed the PC and reset the ECU. Fires up, responds instantly to throttle, tach about 1800RPM. All cylinders hitting. Now once the warm up (WAX unit I believe?) is over and it starts dropping the RPM towards 1100 (standard idle), it starts hitting badly and you can smell gas in the exhaust (with or without PCII). It'll then drop below the 1000RPM mark and start chugging worse, which of course makes it drop lower, until it dies.

I checked the sensors as best I could. I have a Hayne's service manual and did all I could. I don't have the ability to do a vacuum hose test.

The shop says a temp test shows two cylinders cold after warm up. I told them not to change the sparks, oil and battery and I would not pay for it since I already did that. Of course, they try to reason you into letting them, but I'm not that foolish

I just want them to take a look at the fuel injection and the fuel pump (suspected my fuel pressure was not on, did not get any pressure coming off when I release the pressure release bolt on the bottom of the tank).

I'm willing to put some dollars into them testing it beyond what I can readily do without buying more tools, but I also don't want to get ripped off or not know my options. If the two cylinders are not hitting, which I agree with them just from listening and feeling, I'm not real sure what is next (not that inclined, eh). Need some advice or knowledge. Coil is located where and is controlled by? If FI are clogged or fouled, can I pull them myself and take them to be cleaned? Dealer cleans them or just a local mechanic? Specialty shop?

Appreciate any knowledge or comments. I'd like to be the one to do all the work on my baby, though it doesn't seem to be working out.

Thanks!

[silvertippr2001]

I had a similar problem some time ago and all started with a full tank of a crap gas on a (I want to blow up) gas station.

I had to take the injectors off, clean them and they were dirty as hell.

I went nuts, just how you mite be now, but don't be, take it easy and trie to clean the injectors first. if you have the hanes manual thats all I had and I did it by my self. you just need some time and lots of "help me god" just kiding realy is not that hard.

P.S

I cleaned the injectors by my self too, I used a can fuel injector or carburator cleaner and a white cloth to shake the cleaner of the injectors.

I used white to see the dirt coming of the injectors, mine had a lot of black stuff on it.

hope that will help, it did for me !

[beondwacko]

From a non professional but experienced ( automotive ) viewpoint,,,,

It sounds more like an ignigtion problem from here. Fuel injectors don't just start dumping at different temps. But , ignigtion coils when faulty will act differently when they are physically warm vers' cold.

If you have a bad winding in one of the coil packs, as it heats up , the material ( windings ) will expand. If a winding has a break in it, it is quite possible that it will only faulter when it gets warm enough and you'll drop 2 cylinders either intermittantly or all together. For sure check the header for which cylinders are dropping. Once you narrow that down, and if it's a common coil to those cylinders , I would ask one of the members here on the forum what the coils should ohm out at. Then check the resistance on both units when the bike is warmed up, or at least do a spark test on the coil you have narrowed down as the culprit. Don't forget , if you do this testing with only doing a spark test ( with a neon inline tester ) you may be generating enough voltage to light the tester , but not enough to create a strong spark at the plug.

[Alpha Crow]

Allright, I'm going to try to clean the injectors and check out the ignition coils. I'll look in the hayne's manual, but if anyone has more advice on the coils, I'd appreciate it. Experienced advice is better than a picture book where everything is peachy-king every step of the way ("No, I don't see the #$@#% bolt in the picture!").

The shop is apparently worthless. They tested, cleaned some sensors off (my foot...) and wanted to change the spark plugs. I told them no... so they call back that after they changed them, nothing was improved and they took the PCII off and it works better, but not fixed... and kinda stopped there like maybe that was good enough.

So after I spoke with the manager and told them to put the plugs back in and I'm not paying for that service and that "take the PCII off..?" is NOT an answer... anyway, I'm going to pull it out of the shop and work on it myself since they don't know what they are doing. I'm amazed and scared by how they know less than I do about a motorcycle or an engine for that matter.

[jrdxx]

The first thing I would try would be to physically swap the ignition coils, and see if the problem is transferred to the other two cylinders. If the problem moves, then you have at least narrowed the source down to that part of the ignition system, and possibly the coil itself.

[XXTi]

I agree. That's why I asked about the coil in my earlier post.

Start with the basics and work from there. I wouldn't just assume it's an FI problem. Do you have 12 volts to the coils? Are any coil wires shorted after you replace the plugs? Etc.

[ironmike]

My '99 exhibited similar symptoms... bottom line - it was the fuel pressure regulator (on the end of the fuel rail). There's a membrane that was compromised, developed a perforation. At first, the bike would fire up fine, then it would start missing, and finally cylinders 2 & 3 would stop firing altogether. Pressurized fuel was leaking past the regulator membrane and entering the the vacuum lines to cylinders 2 & 3, flooding them out... raw gas into the exhaust, white smoke/vapor, heavy gas smell (if you felt like sticking your face in it).

It drove me nuts for a while. I tried everything mentioned above - and then some (even a "borrowed" new ECM form a "new" unsold '03). I found out the coils are damn near bullerproof, and barring a loose connection are hardly ever a problem. The ECM is pretty tough , too... unless you crack the case which will invite moisture in.

As my regulator diaphragm further deteriorated, more fuel flooded 2 & 3 more quickly, so it reached the point that it would only start and run on two cylinders. A very sharp tech at the Shreveport delareship (G&C Honda) - I gave up and sought professional help - figured it all out.

Check your vacuum lines for raw fuel (key on, fuel pump operating).

Lines should be dry; fuel presence indicates an internal system leak - the pressure regulator is the most likely suspect.

The good news - it was all covered under Honda's five-year emissions warranty... look in the owner's manual for a copy.

[beondwacko]

IronMike;

Wow , good find. That must have drove you nuts trying to find a problem that lead to the regulator. That's not an item that usually goes bad.

[Alpha Crow]

Ironmike, you're beautiful. That was it, exactly. I mean, exactly. Part costs $50, which is not bad at all (though not good...).

Thanks a million, I can get my bike running again!

[ironmike]

I'm glad to have been of help. But I can't really take any credit. It took a very sharp tech to finally solve the issue, as there had been no prior record of that particular component failing. In a conversation after the repair he speculated that the current quality of available fuel - and more likely the age of it and its additive packages - may have contributed to the membrane deterioration... he was certainly no fan of ethanol/reformulated fuels, FWIW.

8)

[Alpha Crow]

BTW, did turn out I got a bad tank of gas, that had a high moisture content. Buddy on a Harley topped off at the same time from same pump and had issues from it. His was easier to diagnose as a carb'd bike, but I think that might have had something to do with the membrane failure (probably was on it's way down, but that was the straw that broke it's back, eh)