Tuning problems 1397/pair converted to pump

[cbibb]

Hey guys I will give as much info as possible so hopefully you guys can help me I have a 2000 with a lees performance 1397/full brocks alienhead/complete aftermarket fuel system (pump/reg/injectors). I recently installed a power commander 5 as I had an ancient 2 and my tuner could not tune the bike with the old one. I am having issues with the bike surging/bucking and not very good throttle response. After he tuned it with the power commander 5 the bike ran great for about a month then it all started again and has progressively gotten worse.I called him and asked why the bike would start running like this again? I explained that the bike had the pair valve converted to a pump through the crankcase and that I have read that the bike had to be tuned differently because of that. He said that would make no difference on tuning the bike. Something is definitely going on to not be able to hold a tune for more than a month. Should I do the pair block off and have it tuned again or leave it as is or??? Or does the pair "pump" have anything to do with my problems? Thanks. EDIT I also want to add that the throttle bodies were synced and the tps set when he dyno tuned it. I rechecked the tps after it started running bad again and its still right in the middle.

 

[POWERHOUSE]

Hey guys I will give as much info as possible so hopefully you guys can help me I have a 2000 with a lees performance 1397/full brocks alienhead/complete aftermarket fuel system (pump/reg/injectors). I recently installed a power commander 5 as I had an ancient 2 and my tuner could not tune the bike with the old one. I am having issues with the bike surging/bucking and not very good throttle response. After he tuned it with the power commander 5 the bike ran great for about a month then it all started again and has progressively gotten worse.I called him and asked why the bike would start running like this again? I explained that the bike had the pair valve converted to a pump through the crankcase and that I have read that the bike had to be tuned differently because of that. He said that would make no difference on tuning the bike. Something is definitely going on to not be able to hold a tune for more than a month. Should I do the pair block off and have it tuned again or leave it as is or??? Or does the pair "pump" have anything to do with my problems? Thanks. EDIT I also want to add that the throttle bodies were synced and the tps set when he dyno tuned it. I rechecked the tps after it started running bad again and its still right in the middle.

The PAIR hose you have going to the crankcase breather should have been removed from the breather and blocked. The PAIR system connected normally pumps air into the exhaust making the readings look leaner than they are. Your tuner should have known this. The fact that it is no longer pulling air from the airbox, but from the crankcase instead, does not change the fact that it is still pulling air, pumping it into the exhaust, and diluting the readings. Sounds like you need a new tuner . . .

 

[cbibb]

Thank you very much for the reply. Thats what I was afraid of. Im thinking of just blocking it off and retuning it. Its a street bike now so it wont kill me if I lose a couple horsepower.

 

[POWERHOUSE]

Thank you very much for the reply. Thats what I was afraid of. Im thinking of just blocking it off and retuning it. Its a street bike now so it wont kill me if I lose a couple horsepower.

Whatever you do, DO NOT block that hose while it is still connected to the breather! Get it off of there. If you want to block the hose after you disconnect it, that would be okay. Kawasakis, Hondas, Yamahas and a lot of other bikes have "clean air systems" that need to be disabled while tuning. Any tuner that does not know this would be better off selling slurpees at 7-11 . . .

 

[cbibb]

Ok got some new news today. I called my tuner and he said he DID block the pair system when tuning. He said to him it sounds like the tps may be going bad. He said "think about it, how would it run great for a month then start running bad again?" Does that sound feesable? I think Im going to go ahead and block off and remove the pair stuff (already ordered the plates). Is there anything that I need to do in order to do this correctly since my bike is using the pair valve as a pump? I want to make sure I dont block off anything that shouldnt be. I am assuming the crankcase hose foes somewhere (airbox maybe)?? Thanks for any advice/help

 

[POWERHOUSE]

Ok got some new news today. I called my tuner and he said he DID block the pair system when tuning. He said to him it sounds like the tps may be going bad. He said "think about it, how would it run great for a month then start running bad again?" Does that sound feesable? I think Im going to go ahead and block off and remove the pair stuff (already ordered the plates). Is there anything that I need to do in order to do this correctly since my bike is using the pair valve as a pump? I want to make sure I dont block off anything that shouldnt be. I am assuming the crankcase hose foes somewhere (airbox maybe)?? Thanks for any advice/help

IMO, you should do one simple thing before you start going crazy: take a spark plug out and see if it is black. FYI, that is how a bike can run good for a while and then start running badly - it fouls the plugs. Just take a look for sh**ts and giggles, let us know if the plugs are nice and tan like they should be . . .

 

[cbibb]

I will definitely do that tomorrow after work and report my findings.

 

[cbibb]

Pulled all 4 plugs today and they all looked perfect. Nice light brown on all four. Put the bike in dealer mode and the tps was right in the middle. I started the bike in dealer mode and slowly gave it gas and the tps rose to the top as long as I was on the gas. Not sure how "quickly" the line is supposed to move but it seemed a little slow to react to me (maybe thats normal though). The line for the tps did not move at all from the middle when the gas was blipped. Again not sure if thats normal or not.

 

[POWERHOUSE]

Pulled all 4 plugs today and they all looked perfect. Nice light brown on all four. Put the bike in dealer mode and the tps was right in the middle. I started the bike in dealer mode and slowly gave it gas and the tps rose to the top as long as I was on the gas. Not sure how "quickly" the line is supposed to move but it seemed a little slow to react to me (maybe thats normal though). The line for the tps did not move at all from the middle when the gas was blipped. Again not sure if thats normal or not.

Okay, that is good. It is not a TPS issue and if you are not triggering an FI light I seriously doubt there is a component issue. Next thing to try is to TEMPORARILY disconnect the powercommander at the throttle body harness and plug the harness back in normally. Take it for a ride - don't beat on it - just check how it runs in the area that was bucking. See if there is ANY change . . .

 

[cbibb]

Again, MANY thanks for all your help!! Will have to wait till tomorrow to take it for a spin. The sky just opened up here and its pouring! Not sure if any of this has anything to do with my issues but wanted to give as much info as possible. When I had the airbox off there is a bundle of 4 wires (one going to each of the spark plug leads) they did not go to anything and were taped off so they wouldnt short out. Every "port" on the airbox was blocked off except the one in the middle towards the back of the bike (I am assuming thats where the crankcase hose goes normally). I have no idea what they would have gone to?? The bike also has a pingle air shifter (and anytime its used the FI light starts flashing until I turn the bike off and restart it). Also has a shift light, nitrous, 2nd fan installed (run through a toggle switch). Again dont know if any of this matters, just wanted to give as much info as possible.

 

[cbibb]

Okay I bypassed the power commander and took it for a ride. Idle seemed a little rougher, the surging/bucking issues may have been a little worse, but not much worse at all. I thought the bike would be running like crap with it bypassed. So i hooked up the power commander again and took it for another ride. It did idle a little better like this and overall maybe a little smoother but not much. Then my tuner suggest I put the bike in dealer mode and watch the TPS on the dash It seemed to be working perfectly. When I was riding and gave it gas it went to the top and stayed there everytime, when I let off it went in the middle and stayed there. I am assuming thats what its supposed to be doing. I also did forget to mention the bike has a 24 volt starting system, not sure if that matters at all.

 

[POWERHOUSE]

Okay I bypassed the power commander and took it for a ride. Idle seemed a little rougher, the surging/bucking issues may have been a little worse, but not much worse at all. I thought the bike would be running like crap with it bypassed. So i hooked up the power commander again and took it for another ride. It did idle a little better like this and overall maybe a little smoother but not much. Then my tuner suggest I put the bike in dealer mode and watch the TPS on the dash It seemed to be working perfectly. When I was riding and gave it gas it went to the top and stayed there everytime, when I let off it went in the middle and stayed there. I am assuming thats what its supposed to be doing. I also did forget to mention the bike has a 24 volt starting system, not sure if that matters at all.

The next thing I would suggest is that you carefully check how your fuel lines are routed. Because you are running a custom setup, I would assume you have an external pump and regulator - similar to what is run on many turbos. It is common for a customer to prop the tank up to do whatever, put it back down and all of a sudden the bike is not running right. What typically happens is that the RETURN line back to the tank becomes kinked somehow - caught on something, bent over, whatever. Check your fuel lines, make sure when the tank goes down (and you may need a little flashlight to confirm this) that the lines - especially the return line - is free and clear. If a return line gets kinked, it will kick the fuel pressure up and cause bucking, surging and other issues. Check this next. . .

 

[cbibb]

Will do, but dont think thats my problem. I have a fuel press gauge mounted to the left of the handle bars and I am always keeping an eye on it. I definitely would notice the fuel pressure rising. Think it has any thing at all to do with the k/n air filter? Through my research it seems like those things have caused more problems than not. Still wouldnt explain why it would run so good for about a month then start running bad again. If the pair hose to the crankcase came off somehow could that cause any issues? Last time I changed the oil I thought it seemed a little loose. I am still going to go ahead and do the blockoffs just to clean up that are if nothing more. Mind if I email you a pic of the bike to see if you possibly know it? I know it was on psychobike when the previous owner had it for sale. He was originally from Virginia.

 

[POWERHOUSE]

Will do, but dont think thats my problem. I have a fuel press gauge mounted to the left of the handle bars and I am always keeping an eye on it. I definitely would notice the fuel pressure rising. Think it has any thing at all to do with the k/n air filter? Through my research it seems like those things have caused more problems than not. Still wouldnt explain why it would run so good for about a month then start running bad again. If the pair hose to the crankcase came off somehow could that cause any issues? Last time I changed the oil I thought it seemed a little loose. I am still going to go ahead and do the blockoffs just to clean up that are if nothing more. Mind if I email you a pic of the bike to see if you possibly know it? I know it was on psychobike when the previous owner had it for sale. He was originally from Virginia.

With that pressure gauge on board, you know that's not the issue, and a K&N would have to get pretty dirty to suddenly cause an issue. The PAIR hose coming off your crankcase evac setup would not have caused the problem you described, IMHO. Do the blockoffs, put fresh plugs in and give it another go. . .