Help required. Bike stranded, secondary air valve fusing ingition

[abarber]

Just had what appears to be another secondary air valve failure that instantly blows the ignition fuse, rendering the bike immobile.

The first time it happened was in the middle of a touring holiday, rendering the bike useless for most of the trip. Symptoms are the ignition cuts out, all instruments / fuel pump down. Going through the fuses, the ignition fuse is blown. Putting another in there and it blows instantly again.

Anyway, this was fixed under warranty by a helpful Italian triumph garage back on September, apparently the air valve solenoid failed in such a way as to short the circuit.

Now, about 2k miles later I have this again. I'll need to get the bike recovered back to my Triumph dealer, but clearly want this fixed for good.

It's a UK 2008 ST 1050, 4k miles.

Anyone that can shed any light on this? Would be much appreciated.

[CLB]

Fixed in September and already exhibiting the same symptoms? I would be suspect of the diagnosis.

The high side of the SAI solenoid is common with the high side (12V) of the injectors. The solenoid coil would have to short to pop the ECU fuse. I haven't heard of any shorted SAI solenoids, it's hard to believe you had two in a row.

If it were my bike I would:
Stock up on fuses.
Disconnect the SAI solenoid.
Pull the hose between the airbox and SAI valve.
Install vacuum caps on the airbox and SAI valve.
load tune 20254 if S/N<317408, 20171 for S/N>317409.

The caps are required because the normal position of the SAI valve is open.
The tune is required to run correctly without SAI.

If it still pops fuses, it's a harness short (most likely), injector, coil etc, not the SAI.
Inspect the bike for pinched harness or harness stretched over sharp metal.

Originally Posted by abarber

Just had what appears to be another secondary air valve failure that instantly blows the ignition fuse, rendering the bike immobile.

The first time it happened was in the middle of a touring holiday, rendering the bike useless for most of the trip. Symptoms are the ignition cuts out, all instruments / fuel pump down. Going through the fuses, the ignition fuse is blown. Putting another in there and it blows instantly again.

Anyway, this was fixed under warranty by a helpful Italian triumph garage back on September, apparently the air valve solenoid failed in such a way as to short the circuit.

Now, about 2k miles later I have this again. I'll need to get the bike recovered back to my Triumph dealer, but clearly want this fixed for good.

It's a UK 2008 ST 1050, 4k miles.

Anyone that can shed any light on this? Would be much appreciated.

[oldndumb]

Brit sprints got SAI? I was under the impression they were configured same as Aus and NZ?

[Pickle Jim]

Yeah we got SAI

UK bikes are to Euro Spec

[abarber]

Thanks for the help, especially CLB.

All I can go on in terms of the first occurance is feedback from the Triumph dealer. They stripped a lot of the bike and tested parts of the loom. It was traced to this solenoid and when replaced, the fuse stopped blowing.

Obviously unless I'm berluddy unlucky (won't be the first time), there is some other underlying wiring related issue. Quite what it is I do not know. Thanks for the tips, appreciated.

As I was able to push the bike home (failed 1/4 mile away), I would rather not have to get it recovered on a flat bed. Can I just disconnect the SAI solenoid and ride it 5 miles or so? Not worried if it throws any codes, as they can reset it.

If so, I assume I will need to remove the tank / airbox to get in there??

Regarding junking the SAI itself, I assume I'll need some sort of software / lead to upload a new map, as my Triumph dealer won't upload a non-standard map?

[Lazarus Long]

Confused again. Anyone that can explain what a SAI is and what it do?
Thanks Laz.

[DaveM]

Originally Posted by Lazarus Long

Confused again. Anyone that can explain what a SAI is and what it do?
Thanks Laz.

Hey Laz,

It is "Secondary Air Injection" and I have absolutely no idea what it does or how it works!

DaveM

[abarber]

Well, I'm currently waiting for the bike to be recovered to my local dealer. I called Triumph UK and they were helpful, already contacted the dealer to suggest possible causes. They will also follow up apparently.

At least this time it hasn't left me stranded at the top of Stelvio Pass, Italy! Still got some recovery truck sun tan from that one!

[Pcdabbler]

Have it recovered. Unless you cap off the SAI Pipes as recommended your bike will run very rich and wash out the oil on the bores. SAI valve failure (fails open) has caused at least two engine rebuilds that I know of from the forums due to excessive rich running. It's an emmissions reducer, lets Air into the exhaust line, also helps to heat the Cat up quickly.

From Wiki :
As emission control strategies grew more sophisticated and effective, the amount of unburned and partially-burned fuel in the exhaust stream shrank, and particularly when the catalytic converter was introduced, the function of secondary air injection shifted. Rather than being a primary emission control device, the secondary air injection system was adapted to support the efficient function of the catalytic converter. The original air injection point became known as the upstream injection point. When the engine is cold, air injected at this point cleans up the extra-rich exhaust and raises the temperature of the exhaust so as to bring the catalytic converter to operating temperature quickly. Once the engine is warm, air is injected to the downstream location — the catalytic converter itself — to assist with catalysis of unburned hydrocarbons and carbon monoxide.

[abarber]

Thanks.

Truck on it's way.