Looking for some advice on what all to check on my 2008 Mastiff EFI, to correct whatever is causing this pesky "check engine light" that I've had since I bought it a couple of years ago. I don't have any diagnostic equipment, so I'm unable to do that type of trouble shooting. I'm not opposed to replacing parts / sensors, as long as I can narrow it down a bit. I just got the bike back from Strokers, after they completed the accident repairs from last year's unfortunate incident. While the bike was there, I asked them to diagnose the issue. Rodney told me that they could not find any issues & that the light never came on for them. They only noted the faint "glow" that's always there, which I've seen in some other threads. We both assumed that perhaps it might have been a bad 02 sensor, since they replaced those when they put the new exhaust on. Sure enough, on the ride home, the light comes on again. I can perform a reset & make the light go off, but just about every time I go for a ride for more than 10 - 20 miles, the light comes back on. Oil level is fine & fresh. I put new plugs & wires on last year just before the accident, and had recently replaced the crank position sensor. Any advice & guidance is greatly appreciated!
That pesky "check engine light"
- Thread starter TexasMike
- Start date
Check your intake gaskets, injector "O" ring and throttle body gaskets. I have never worked on a EFI Bike, but my neighbor has a small shop and he told me that area would be the first thing he would check. Good Luck
Carlos
Carlos
Mastiff Rider64
Well-Known Member
you'll have to read the codes in the VFI. That's the only way to narrow down your search. Know that the VFI and check engine light has nothing to do with the functions of the EHC. The Engine light from my understanding from S&S only has to do with fuel side of things. Like o2 sensors, engine temp, mass air flow sensor, throttle position sensor, now the question that I wonder is your VFI locked or unlocked. Meaning can it be tuned or does it have a tune limit. When I first got my bagger the engine light never came on. Until I changed pipes, air breather and cam. Then the engine light started coming on and staying on. I'd read the codes and I'd have one tell me the rear cylinder was out of limit or something like that. What it was meaning was that I had surpassed the 20 percent range that the locked VFI would adjust fuel for. So the only way to adjust the MAP was to get an unlocked VFI, which I luckily did from S&S for about $1,000 bucks. Now the only problem is finding a mechanic that can use the software and know enough about S&S vfi system. Because let me tell you, I've been looking. My local shop mechanic is S&S pro tune certified and a certified S&S mechanic, but he has yet to keep my check engine light from coming on. I have contacted S&S and they wont even mess with this system. They will make me a MAP if I send them my engine number and tell them what all I have done to the bike, but wont guarantee that the light wont come on.
I did recently talk to a guy that runs a shop in Columbia SC that said he could switch it over to Carb for around $1,000 bucks plus parts. And I had actually been thinking about doing that a while back. But I keep trying to let my local mechanic figure this system out.
I did recently talk to a guy that runs a shop in Columbia SC that said he could switch it over to Carb for around $1,000 bucks plus parts. And I had actually been thinking about doing that a while back. But I keep trying to let my local mechanic figure this system out.
Jwooky
Well-Known Member
This is all perfectly correct, but don’t revert back 50 years to a carb, that’s a huge downgrade.
My advise is as follows. Start with a map that is as close as possible to your configuration cam etc.
Ride the bike, at varying speeds and loads, rolling in and out of the throttle for 5miles or so.
Assuming it’s running well, and no other issues it will self tune via the wide band O2’s.
When you get home, merge the newly tuned adaptive maps to the main table to make them permanent. This will reset your 20% base line (Sites).
Do this a couple times and your tune should be very close to optimal and won’t set the Bad sites fault any longer.
WATT does the bike feel like? Starts all the time? Plug colors are? WOT is the driveability like, meaning, no flat spots, does not lag, has excessive popping out the exhaust, and/or air cleaner housing?
WATT is going on is an 02 sensor removed from that year? Say no 02 for that year. Then, the CEL is maybe a poor fuel pump? But, has to start fast, WOT is no problem at its highest rpm limit, then not the pump.
Say it clears, but comes back. An 02 would trigger that [if eliminated]. Bottom line, you'd have to download the code(s) to pinpoint who is out of spec, open, shorted, connector not connected, wire out of connector.
Analog means many inputs. That simply means not out of spec, short, open, wire dangle, connector disconnected.
Digital sets the code as input. That simply means in processor speak, it sends a single digit of 0000000. That means sensor is out of spec, wire open, a short, wire out of connector, not connected.
So processor wise, it is slow to set the CEL back on, but shows it's sending in a single digit over and over, not many numbers like vac movement just bumping the throttle you can't feel is 1010111010010101 or analog input. Get it? This is FI in the basics.
Say it did have an 02 for that year bike. You went from closed loop to open loop. The processor has this backup/fail-safe/limp mode in FI. It's a method that reverts back to 14.7 psi as the alpha number to calc off of. Uses the TPS for low throttle input, and calcs off the TPS for heavy throttle load. This covers your ass is the Huston, we have a problem is brought you full circle.
Right back to my first question is how does it run? Then ignore the light fandango. You would have already burned a hole in the piston, overheated it with any mode you did. This would limp the bike with a fuel and ignition change. That's the limp. Do you feel it? No? Fuck it. Put black tape over it if you can't stop thinking about it.
Signed,
Limp City Downloaders Delete Club
WATT is going on is an 02 sensor removed from that year? Say no 02 for that year. Then, the CEL is maybe a poor fuel pump? But, has to start fast, WOT is no problem at its highest rpm limit, then not the pump.
Say it clears, but comes back. An 02 would trigger that [if eliminated]. Bottom line, you'd have to download the code(s) to pinpoint who is out of spec, open, shorted, connector not connected, wire out of connector.
Analog means many inputs. That simply means not out of spec, short, open, wire dangle, connector disconnected.
Digital sets the code as input. That simply means in processor speak, it sends a single digit of 0000000. That means sensor is out of spec, wire open, a short, wire out of connector, not connected.
So processor wise, it is slow to set the CEL back on, but shows it's sending in a single digit over and over, not many numbers like vac movement just bumping the throttle you can't feel is 1010111010010101 or analog input. Get it? This is FI in the basics.
Say it did have an 02 for that year bike. You went from closed loop to open loop. The processor has this backup/fail-safe/limp mode in FI. It's a method that reverts back to 14.7 psi as the alpha number to calc off of. Uses the TPS for low throttle input, and calcs off the TPS for heavy throttle load. This covers your ass is the Huston, we have a problem is brought you full circle.
Right back to my first question is how does it run? Then ignore the light fandango. You would have already burned a hole in the piston, overheated it with any mode you did. This would limp the bike with a fuel and ignition change. That's the limp. Do you feel it? No? Fuck it. Put black tape over it if you can't stop thinking about it.
Signed,
Limp City Downloaders Delete Club