2007 Big Dog Bulldog EFI Spitting and Sputtering

[FlyboyRuss]

Need Some help. 2007 Bulldog EFI with new RIP Install runs perfect until you ride it for about 45 minutes then it starts to spit and sputter and progressively gets worse. After the mechanic hooked it up to the computer using the S&S Pro Tuner program it shows a code that as soon as you reset it she runs great but will still do the same thing after another 45-minute ride. S&S said it sounds like it might be sucking air but they checked that and its not that, and again she runs perfect for that 45 minutes to an hour each time. Already, replaced the two exhaust sensors, and throttle position sensor which the computer showed were bad when I initially dropped it off. No other errors showing up on the computer.
Russ

 

[mittens]

Fuel pressure? Heat as the bike warms up the fuel pump is not liking life? I would watch that and see if it starts to take a dip

 

[FlyboyRuss]

Fuel pressure? Heat as the bike warms up the fuel pump is not liking life? I would watch that and see if it starts to take a dip

Even when spitting and sputtering if I get on it she takes off without a problem. So I don’t think fuel pressure is it if she runs great when I demand the fuel even after she is heated up.

 

[mittens]

When bike is revved voltage is spiking and the fuel pump could be seeing that spike to help it keep up....
Motor needs 3 things. Fuel, Spark, and Air. I dont think your air supply is changing randomly, (Filter flopping around or thorttle blade stuck/loose.)

That leaves fuel supply, IE Pump or injector (in your case if EFI) or Spark.

Coil could be getting hot and failing, or wire could be getting hot and not liking it as well. But they tend to not work under loads as well once this happens and fair better under light loads which sounds opposite of what you describe.


Fuel pressure is an easy check, just my suggestion. Forums great to get ideas and bounce them around. Only giving my thoughts.

 

[Jersey Big Mike]

I know I'm going to get flak for this but try this -- change your spark plugs to E3 Brand, You can get them at most auto stores usually where the small engine (lawn mower) plugs are.
I had some weird EFI stuff years ago and switched and never looked back.

What code is it showing?

 

[mittens]

I second Jersey Mike!

I will say my NUMBER ONE thing I tell people when something has a miss or hiccup is change plugs? hahaha

Thats a left over from 2 stroke days but I will be damned how many times it works. and its cheap

 

[FlyboyRuss]

Will have him check fuel pressure. We put new plugs and wires in as the first step to fix it a few days ago. Thanks for the feedback. I need all the brain power and I can get to compensate for my lack of. Lol

 

[Jwooky]

Too much guessing going on here.

You need to connect with protune and see what the faults are, always first step.

Clearing a fault will not make an issue go away.

That said, as the bikes age they collect debris, so if you haven’t for EFI bikes I highly recommend going through the fuel system and replacing the filter on the pump and injectors, and even consider replacing pump and regulator while you have apart as they are only ~$100 as preventive maintenance.

I have personally experienced bikes that will run decent, then as you ride the suction will slowly pack and clog the filters. You stop and it can loosen up and run better for a while.

 

[FlyboyRuss]

Does anyone know of the guy the guru in the southeastern US that can work on a BigDog. I have now been to my third mechanic one in Daytona and two in GA and no one can figure out what’s wrong with the bike. And S&S tech line has told them they don’t know what’s wrong with it?

 

[FlyboyRuss]

Too much guessing going on here.

You need to connect with protune and see what the faults are, always first step.

Clearing a fault will not make an issue go away.

That said, as the bikes age they collect debris, so if you haven’t for EFI bikes I highly recommend going through the fuel system and replacing the filter on the pump and injectors, and even consider replacing pump and regulator while you have apart as they are only ~$100 as preventive maintenance.

I have personally experienced bikes that will run decent, then as you ride the suction will slowly pack and clog the filters. You stop and it can loosen up and run better for a while.

yeah I’m thinking of bringing it back home and stripping down and replacing just about everything.

 

[HMAN]

Just my thoughts n Im an idiot so take it for what its worth. Ima KISS kinda thinker.... have you tried loosening the gas cap when she starts to falter? Im thinking that because you say when you roll the throttle when she falters it takes off. These caps have been known to cause some issues. If you havent, try removing the white 'vent plug' on the inside of the cap.

 

[Jersey Big Mike]

yeah I’m thinking of bringing it back home and stripping down and replacing just about everything.

Before you do that, run protune and see what code you are getting -- that may give us more info so we can better target our answers.
As to the E3's -- I had a EFI system screwing up -- plugs fouling in 300 miles -- changed to E3's and problem went away and I was able to track down the culprit (02 sensor) and get it back to normal but as a result, I only run E3' now in that bike and prefer them in my carb'ed bike as well.