2007 Big Dog Bulldog EFI Spitting and Sputtering

FlyboyRuss

New Member
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

Active Member
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

New Member
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

Active Member
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.
 
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mittens

Active Member
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

New Member
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

Well-Known Member
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

New Member
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

New Member
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

I just like my Freedom
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

100K mile club
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.
 

gate's bulldog

New Member
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
would you happen to have an exhaust leak at the head exit if so
this would suck up air and give false reading to the o2 sensor
it did happen on my 2010 bulldog
 

airborne2201

Learning every day!
I know I'm going to get flak for this but try this -- change your spark plugs to E3 Brand,
I'm having an issue with sputtering and only one piston firing after a cold ride. I just had the shop replace my spark plugs this year with some strange German ones, so good advice, I'll try changing to the old ones and see if both will fire at low idle. I have to get the bike going into 2nd gear and above 2k RPMs to get the front piston to fire. Checked the connections, so it was not those components. Thanks as always for the sound knowledge!
 

Snuffy

Active Member
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?
Knothead is one of the best IMO. It’s worth the trip to Tennessee I can assure you. If he can’t fix it then you can set it on fire. Most honest and reasonably priced mechanic ever. So just take it to Knot and be done with it. Btw he will tell you he don’t know shit about EFI but he made mine like new.
 

Jwooky

Well-Known Member
I'm having an issue with sputtering and only one piston firing after a cold ride. I just had the shop replace my spark plugs this year with some strange German ones, so good advice, I'll try changing to the old ones and see if both will fire at low idle. I have to get the bike going into 2nd gear and above 2k RPMs to get the front piston to fire. Checked the connections, so it was not those components. Thanks as always for the sound knowledge!
With an EFI bike , the first step should always be to connect to protune and check for faults.
 

airborne2201

Learning every day!
With an EFI bike , the first step should always be to connect to protune and check for faults.
It was the spark plug, took it out and switched them, the other cylinder fired right up. Only have about 1,400 miles on these Screaming Eagle plugs. The only ones I could order for this weekend as a quick fix were the NGK 3932 from my local shop. I'll have to see if I can get some nice E3 ones passed through customs, they are always a pain in my side when it comes to getting US parts.
 

Jersey Big Mike

100K mile club
It was the spark plug, took it out and switched them, the other cylinder fired right up. Only have about 1,400 miles on these Screaming Eagle plugs. The only ones I could order for this weekend as a quick fix were the NGK 3932 from my local shop. I'll have to see if I can get some nice E3 ones passed through customs, they are always a pain in my side when it comes to getting US parts.
Try using the E3 site direct -- looks like they will ship to Germany.
Or find a car pro shop and see if they carry E3 and get them to order a set for you.
 

Sven

Well-Known Member
Russ says:
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.
The 45 minute's widow is peak thermodynamics and signs off. More sounds like heat related.

...Pro Tuner program it shows a code that as soon as you reset it she runs great
Name the specific code and who/watt is the sensor?

... will still do the same thing after another 45-minute ride.
So is goes something like this:
1. connector not connected.
2. wire out of connector,
3. short.
4. open.
5. sensor.

So (1 is so obvious it's not it. (2 could be ever so connected so as to chemically grow this white power between connectors. (3 would blow fuses. (4 would be something like vibrating a single wire to stress crack and show an open at the wire strands and not necessarily crack open the plastic sheath around it. (5 would be a sensor out of signal range, an ohm reading breaking out of said spec.

S&S said it sounds like it might be sucking air but they checked that and its not that
Did you mention after the cleaning of said code, the bike runs tits? An air leak does not seal up clearing a code.

... she runs perfect for that 45 minutes to an hour each time.
Say we could pull each sensor off for new and it wont pinpoint who in the loop is it? You'd have to commit number 1 for it to set a code. Make sense?

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.
Kind of see it's not plugs, their wires, gas caps, fuel pumps, or sensors that do not return to itself but said wires into and out of said codes? Kind of seeing it's now making sense is a code clears from the major players, like 02's and TPS telemetry?

My take on it is age and it's chemical reaction to the big E or magnetism: where you cannot separate heat from its chemical reaction. All works well for 45 to an hour's ride? Then this chemical reaction between wires seems like the cause. More like a dunk of wires into a solution of vinegar and hydrogen peroxide, rinse and reconnect. That or spray WD40 at it, shake the wires while spraying.

But to narrow it down, I'd run the connects from the TPS and look at those. With the 02 it runs closed loop. With a disconnect, it runs open loop, ignores any kind of fueling problem, but runs a lookup map as a 'backup' a 'fail-safe.'

The TPS is to run it with a disconnect and see if this sets the shitty running. Reconnect and see it cleared up on the reconnect. This might narrow it down to wire integrity from sensor all the way back to the RIP.

This wire run shows good, I'd question the new unit you installed.
 

Snuffy

Active Member
Thanks Sven for taking the time for this. It is quite informative. There’s a few of us new to the EFI game and this helps. I too feel that if it was ok before the RIP then that’s what I would suspect. I have heard good and bad things about the RIP. Best of luck and hope you’re riding soon Russ.
 
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