Spluttering Rocket

Hi,

Been searching for an answer as to why my bike keeps developing bigger splutters under load. In fact its running rich.

Background: 06 bike with garrett turbo fitted. (15 months ago) Recently it decided to start running rich which results in big splutters/misses etc....

Bike has specific tuneboy tune plus runs a modified PC3. Basically the tuneboy enabled the timing change and has a base fuel map. The PC3 has a maps sensor built into it so as its sees boost it adds the additional fuel required. This set up has been in place since the build without issue.

Thus far: Have taken PC3 out of the loop, still misses. Reflashed Tuneboy tune, run adaptions. Replaced plugs and leads, replaced factory MAP sensor. No fault codes in Tuneboy.vHave unplugged O2 sensor, plugged in PC3 O2 eliminator. Pulled injecotrs and had them tested. Still rich and missing when coming onto boost. In the top end of the rev range it clears but this is probably because it has the airflow to support the amount of fuel.

Anybody else with forced induction set up (or not) encountered this kind of fault ?

Cheers

Mike

This probably sounds silly, but have the plugs and wires been checked? Higher compressions wreak havoc on conductivity.

Have you checked the primary TPS with tune boy. it makes a big differance if its out or has failed.

+1 on wht pedro state check your primary TPS voltage with tuneboy should be like .6 volts I believe. Manual has the correct numbers.

Thaks for your comments,

Yep, have replaced plugs and leads, pretty sure its not coil related.
TPS is correct at .6. Prior to this issue bike was perfect and no settings have changed.

I keep coming back to MAP sensor but the voltage output seems to be correct. This doesnt mean its not faulty. I just replaced it and bike ran fine for the first blast and since has deteriorated once again. Coincidence or did the new MAP fail ? Reading other threads indicates the factory MAP can handle up to 1bar (14.7psi) and I'm running 8lbs.

Baffled and still searching.

Mike

Have you checked to insure that the grounding points and ignition coils are not fouled or the leads to the battery are loose? Sometimes it can be the simplest things. Good luck with finding the source and getting back to some good riding soon!

You need a 2bar MAP READ Hombre Posts on this subject

Madal said:

Thaks for your comments,

Yep, have replaced plugs and leads, pretty sure its not coil related.
TPS is correct at .6. Prior to this issue bike was perfect and no settings have changed.

I keep coming back to MAP sensor but the voltage output seems to be correct. This doesnt mean its not faulty. I just replaced it and bike ran fine for the first blast and since has deteriorated once again. Coincidence or did the new MAP fail ? Reading other threads indicates the factory MAP can handle up to 1bar (14.7psi) and I'm running 8lbs.

Baffled and still searching.

Mike

Click to expand...

1 bar runs from -7 lbs vaccuum to +7 lbs 2 bar is -15 to +15 it does sound like a mao sensor problem is your boost adjustable? Are you still using idles stepper motor? is the sputtering like a cough? with the boost runnig your map sensor is sending the wrong signal to the ECU and it in turn could be sending wrong voltages to the injectors. Pedro is good at this as he helped me to understand. does this happen when your running her up in say the 5 to 7 lb boost range?

Thank you for your wise input.

Yep would agree with comments on the MAP sensor. Previously the bike was running man 7.5lbs boost. At last service we noted the waste gate flap was slightly open so adjusted it a tad. Result is 8 - 8.5lbs boost. Issue only happened after having a big go on the bike, thus exceeding the limit you refer to. I just replaced the sensor with genuine one and went for a blast. All good then the spluttering started again and slowly gets worse. Upon reflection for the past year the bike has never made over 7 -7.5lbs thus no issue has appeared.

Off to source bigger map sensor...

I shall advise of sucess....

Mike

Good luck as the ECU can only read 1 bar map signals and the PCV is not out yet thus leaving two choices the best being a MOTEC ECU about 3500.00 USD ouch I have been wating for it to come down. The other way was recommended ealier in this post which was done by Hombre and thats using a digital fuel adjuster which is basically a frequency interceptor the takes the signal coming from the 1 bar map and send a preprogramed signal to the ECU basically lieing to it. The only place I know of where you can get it is in Austrailia and it comes as a Kit and you have to solder all the little diodes, resitors, and a hole lot of computer geek **** together. Looks like this



I ferked the first one up and had Pedro bailed me out in the end I went back to no map sensor and no idle stepper motor. I often wonder if you turbo dudes can do the same thing and use the TTS tune. Of course I do not know if you changed your injectors or not as with the blower kit you get 668 cc ones and now if you want you can find 1000 cc ones Hombre said. My first question is what type of boost gauge are you useing a vaccuum one or a electrical one? I suspect vaccuum are not accurate when your shoving air (or basically force feeding) down the engines throat. I think a engines sucks in this is the vac created to draw air and fuel in thus NA your basically jamming the **** in, and turbos have so much snoot out the gate they are prone to breaking pistons and rings do to detonation. maybe the installer let some boost blow off so you did not excede the the 1 bar map sensor. after all a NA engine never achieves 5 to 7 lbs of boost maybe you should turn her down a bit and see if it works. Are you using tuneboy? Both my fiends that have turbos have detonated their clutch baskets and let me tell you it was not pretty. Nusseman is on this site he has the mitubishi turbo and when he had it turned up above 550 nm meters it suffered from catasrtophic failure as Brembo's did. and he has secondary injectors with a seperate ECU and water injection and intercooled its holding together with it turned down to 270 HP One bads ass if you ask me and I mean rider and bike he land speed races on ice. Hell IMO that take balls the size of three and a yard and a half of foreskin hanging below your knees