08 starting troubles

hey all!

I have been battling a doesn’t want to start problem for a few days now.

Currently, it will crank and cough once or twice as though it tries to start, or maybe run on the starter, or start just enough for the starter to kick out and then die.

I have replaced the gear position sensor with the current kit, all spark plugs, recrimped coil low side wires, cleaned the crank position sensor, reset ISCV several times, and exercised just about every connector I could find.

After I did all that tonight it started and ran long enough to complete the 12 minute tune and for me to get some data for the pcv-at pressure setup. At about 20 minutes of idling beautifully it shut itself down and will not start again.

Is this the TPS?? Tomorrow morning I will remove it and check the color of the insides and then reset it all and see if it will run again.

I’m at a total loss as to where to go next.

Other symptoms are my pc-v quite regularly loses sink with the crank position sensor through the injector harness. Throttle body balance when warm they are all within 20 of each other - I know it could be better but that is awful close - it will be addressed when it will stay running. Stepper motor does move - I saw it extend quite some distance out at a reset or start test, I don’t recall anymore. MAP values seem to be the same wether it is running or not. I do not know if that means anything or not. Based off the throttle body sync in the manual it should run without the MAP connected so I’m not sure if it being faulty would be trouble. I haven’t seen any error codes either.

If anyone has any ideas I would be forever grateful!

One of the harness connections is poor? Maybe check in case one of the wires is not clipped into its holder firmly. Mind you this is a grabbing at straws guess.

If TPS is bad you will have a HIGH IDLE and erratic idle no matter the inside colour.
double check the earth wire to the PC5 and also all connections to it,
A member on facebook had a similar issue and he says he fixed it by topping up the radiator coolant - don't know why but he says it worked for him.

rash_powder said:

hIf anyone has any ideas I would be forever grateful!

Click to expand...

This is going to sound odd I know.

CHECK EVERY RUDDY EARTH WIRE YOU CAN FIND. The first rule of vehicle electrics is - UNTIL OTHERWISE PROVEN - ALL ELECTRICAL FAULTS ARE EARTH FAULTS. You may also need to trace wire continuity. Could be a dry joint or broken conductor.

That MAP thing :
Mine certainly are NOT the same OFF vs ON (in the PCV) - let alone running.
In TuneECU there is no OFF. Not running and running is different.

If you suspect the PCV - remove it from the equation. I would.

How would one test the crank position sensor?

This morning it started and ran well enough to test ride. If I get more than, I would guess 2% throttle it starts to miss and cough. This causes the bike to feel like a trip or something.

Came home and cleaned up the side stand switch best I could as it is potted and disconnected the pcv. Currently on the battery tender to refresh the battery and give the bike time to relax. Then test again.

Also I poured sea foam into the fuel tank.

It is looking as though a fuel filter service may be in order.

But still, I’m not sure. Just going at things.

I have not yet checked all the grounds. Will need to find a print and then get to it.

How old is your battery?? Load test your battery so you can rule that out!!
Bad battery or almost a bad batter can cause all kinds of weird symptoms!!

My 05 had similar problem. Sat for a time with bad gas. Pick up lines in tank were disintegrating so not enough pressure in fuel rail. good luck

@Jag, I forgot to put in that battery is brand new, changed that as the old one would bleed down to 7 volts in a few days on its own.

So I have been thinking about this prob some more.

It WILL NOT start with the tune that @Claviger posted from two wheel dynoworks. This tune uses the MAP sensor everywhere. It will start and run at idle, and poorly everywhere else, on a stock TORS tune from Triumph. Low speed throttle is horrible chuffs and missing and exhaust pops and Throttle body backfires. Commonality is MAP sensor. I haven’t checked in a few days, but when I did last the MAP volts and pressure were the same engine off as engine running. Vacuum lines are all serviceable and connected. I get no CEL or codes, but could this be a failed/failing MAP sensor? I have to check if the air box MAP sensor is the same as the throttle body MAP, and if it is swap them to see what the values are. Will be a bit for that though as the tank is apart for fuel filter change.

Just out loud thinking here. Someone tell me I’m being dumb if this doesn’t add up.

The two map sensors are not interchangeable. In TuneECU there are two voltages under the MAP sensor area.

1 should stay the same with the bike on or off. The other should most definitely be at a lower voltage with the engine running than with it off.

If both voltages are staying the same with the engine on or off, you’ve found the source of the issue. The MAP sensor or vacuum connections to it are bad.