Help please, 08 R3T not starting

[DEcosse]

I can tell you that at the instant the starter kicks on, the voltage actually drops below 8V! I know this because when I was developing my key-less system I had some issues with the very first R3 ones and discovered that the switches I was using shut off below 8.5V (this was subsequently rectified with a device that operated down to 6V) - you can't see this with your DC volt-meter because it's quite a short duration
But sustained voltage (after that initial hit) I would have to say is actually very good at 11.7V

On the other point, Roadster key-switches do not fail - no headlight current at all through the key-switch
there have been a couple of Touring ones with reported fails I've come across on the forum, but much less prevalent than the Classics as although they do route headlight current through the switch, it is half of that of Classics as only one headlight.
Regardless, if you're cranking strongly, it really does not sound like electrical, at least not in the ignition/starting circuit.

Do you have good Fuel Pressure?
Are plugs getting wet? Tried starting with Ether?

 

[R3R Peter]

Seems to me that the timing is off.
See Service_Manual_R3S_C_T 2007 page 3.8 first Picture

Peter form Cologne

Will introduce later.

 

[Claviger]

Yup, crank is 180 out of phase with the cams.

Will never start like that It will also give good compression and sound appear right, nothing will collide it just wont run.

 

[Jester 76]

The two dots are on the same side of the crank, you just can't see it in the photo. It's really hard to see without pulling the clutch cover but trust me both dots are lined up. There is no distributor or cam position sensor so I don't believe it's possible to be 180 out. I'm assuming that the ecm fires at the top of every stroke.

 

[Claviger]

It doesn't, the ECU knows which cylinder is at TDC and when it's on it's power stroke by a combination of MAP signal and Crank Position sensor. This is why, given all things properly configured and working, it will always crank, crank, fire when starting, the ECU is working out which cylinder to fire during the crank, crank portion.

I see what you mean about the dot.

So back to my earlier post:

Confirm you have fuel, air, spark, compression.

If you've those and it's not firing its a loose wire, Crank Sensor, Map Sensor, kick stand switch, tip over switch, missing alarm jumper, or ECU that can be at fault, I can't think of anything else that will prevent starting if those are all in order.

 

[cootertwo]

Some confusing stuff here. This is post #11
Battery voltage drops to 11.7v when turning over with spark plugs out. With charger hooked up and feeding 80A to AGM battery it starts at 13.8v and when starter is cranked it drops off to 11.7v. Still looking for ideas.
So ?? did it ever start, what were you talking about ?? Beginning to almost sound as if it's nothing but a bum battery

 

[Bob R]

The battery has been checked, it is good. Decosse mentioned that it is common for the battery to drop to 8v or so momentarily during start. He says the 11.7v is more than adequate during cranking so that is off the table. The spark seems very weak to me but I have never seen what kind of spark the R3 makes normally. The cam timing is as perfect as it can be, so something had to happen during the time everything was removed for pulling the valve cover or swapping out to the RamAir.
bob

 

[1K9]

Some confusing stuff here. This is post #11
Battery voltage drops to 11.7v when turning over with spark plugs out. With charger hooked up and feeding 80A to AGM battery it starts at 13.8v and when starter is cranked it drops off to 11.7v. Still looking for ideas.
So ?? did it ever start, what were you talking about ?? Beginning to almost sound as if it's nothing but a bum battery

Or just a bad connection at the battery.

 

[Claviger]

All this battery talk... a huge sag is normal the moment it starts moving, nothing new.

 

[Jester 76]

Just checked compression and only have 15 psi on all cylinders, zero with the throttle open (secondaries at 95%). I left all the other plugs in and disconnected the coil primaries per direction on other threads. What did I screw up?