ST1300 Brains required for non starter

Scotty

Scotty

Joined
Jun 9, 2008
Messages
37
Location
Dundee, Scotland
Bike
2004 1300
The curse of the new season is upon me!!!!
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MOT test was booked for Monday so thought I would fire up the beast, which has been sitting since December, and check it over.

It wont start!! Turns over no probs and got a spark. Dont have 12v to the fuel pump though. All fuses and relays ok, kill switch ok as its turning over. No FI light when the ignition comes on and no flashes when its turning over.

Any ideas? Only the ECU, bank angle sensor and wiring to go. No signs of mice damage or corrosion as its in my garage where it normally gets TLC. Its not the fuel pump as it runs if I fire 12v direct to it. The battery is on a tender and turned it over for ages before slowing. A fresh battery gave the same symptoms. Can't be the Kill switch or sidestand as its turning over. Activate the kill switch and it doesnt turn over. There is no alarm on it or any other additions.

Any suggestions would be appreciated for resuming the chore tomorrow.

It was last run in early jan, no probs, and has had a fuel stabaliser in it as well. Hope its not the ECU!!

Its a standard UK spec 2004. Ive searched other posts but dont see all of the symptoms above.

Many Thanks in anticipation.:confused:
 
I sure hope a mouse did not build a nest under the throttle bodies as several have had that problem where they chew the wires in that area. I am sure others will pop in soon. It could be bad fuel. Good luck!!

Mike
 
Since us yanks don't have them on our bikes, how would the bike behave when immobiliser hasn't decided that the key in the ignition is authorised?

There are a handful of conditions where the ECM won't allow the engine to start, the aforementioned meezus infestation being one of them. Does the trouble code check procedure work? If not, it may be that your ECM isn't getting power or it's toast. (If I had to bet, it would be on the former.)

--Mark
 
Do you hear the relay click but no fuel pump whine when you turned the key to on?
Could be the relay isn't fully seated in it's connector, the rubber boot can make it look like its seated when it isn't..
 
Scotty said:
The curse of the new season is upon me!!!!
--------------------------------------------------------------------------------

MOT test was booked for Monday so thought I would fire up the beast, which has been sitting since December, and check it over.

It wont start!! Turns over no probs and got a spark. Dont have 12v to the fuel pump though. All fuses and relays ok, kill switch ok as its turning over. No FI light when the ignition comes on and no flashes when its turning over.

Any ideas? Only the ECU, bank angle sensor and wiring to go. No signs of mice damage or corrosion as its in my garage where it normally gets TLC. Its not the fuel pump as it runs if I fire 12v direct to it. The battery is on a tender and turned it over for ages before slowing. A fresh battery gave the same symptoms. Can't be the Kill switch or sidestand as its turning over. Activate the kill switch and it doesnt turn over. There is no alarm on it or any other additions.

Any suggestions would be appreciated for resuming the chore tomorrow.

It was last run in early jan, no probs, and has had a fuel stabaliser in it as well. Hope its not the ECU!!

Its a standard UK spec 2004. Ive searched other posts but dont see all of the symptoms above.

Many Thanks in anticipation.:confused:
Click to expand...

Does your oil pressure light go off when you crank it ? .. If you have a manual look at the schematic ( I currently don't have one available but maybe some here can check) and see if the oil pressure switch is feeding the fuel pump relay. I've seen in several applications (gas & Diesel) that use electric fuel pumps, the oil pressure switch is a safety to kill the fuel pump if PSI is below a set pressure, it's also what triggers your oil pressure light. NO pressure circuit closed light on , pressure => switch setting, circuit open light off , 12v to fuel pump relay.

And since this came up on another thread, are you using a OEM key ? .. Just asking ..
 
Well, given it has been very cold, very damp and a long time standing.... this may be a number of things..... but start with fuelling, or lack thereof, then look for spark at a plug.... if you have both of these (fuel and spark), especially if there are sparks at ALL the plugs, then it has to be a voltage issue when cranking, although you say it seems to crank well enough.....

Hmmm.... a good warm up in the garage, if you have one, with a fan heater or hair dryer around the coils and plug leads.

Perhaps a fuel drain and refill with some fresh good stuff too..... wouldn't hurt to try a fresh set of plugs at the same time.
 
Disconnected the battery over night to reset things, no change. I did check the plugs etc again, now I have no fuel or spark. I've stripped the kill switch and con checked it all, its fine and the relays associated to it are operating. Still no FI light at all. HISS light (imobiliser) goes out when the ignition is on so its ok. The oil light goes out when cranked leaving only the neutral light on.

The side stand switch and cables check out ok, as does the bank sensor. Con checks to the coils are good to both the ecu and kill switch. There are no obvious loom breaks from front to rear and all the ecu plugs are good. No breaks or issues with the throttle body harness.

Only one thing isnt quite right though. Only 1.5 volts at the coil when the ignition is on, according to the manual it should be 12v. Any ideas where it comes from as my wiring diagram is poor quality. Seems to be the issue somewhere along this line or the ECU. The bike still turns over no problems at all, the fuel pump still doesn't prime on switch on as there is still no 12v to it. Will tackle it again tomorrow. Any other ideas most welcome as I'm getting to the end of mine. This certainly is the most unreliable bike I've had yet!
 
Scotty said:
The bike still turns over no problems at all, the fuel pump still doesn't prime on switch on as there is still no 12v to it.
Click to expand...

Again, check the ECM for trouble codes. If you haven't done that yet and there's a condition causing it to not run the fuel pump, you're only going to be chasing your tail doing anything else.

--Mark
 
Thanks for the replies so far. Mark, the FI light doesn't come on at all. I've followed the procedure as per STwiki and still nothing on the FI light. Checked the earth point that was subject of the recall and its a good 1.8 ohms. The pink connector seems ok as well. Carl thanks for the link i'll chase through it tomorrow. All of the rest of the electrics and the panel are working fine.
 
I usually troubleshoot using simple stupid first. I read that you tendered the battery and even tried a fresh battery. Have you performed a battery load test on either of those batteries?

Reason I say this is that you mentioned that it ran fine in January and only after storage did you have this problem. So, I'm thinking either your batteries are bad OR something attacked your electrical system like a mouse (usually under the airbox - so you'll have to pull the airbox to see).

Simple load test:

https://www.st-owners.com/forums/showthread.php?52097-Quick-test-of-Motorcycle-Battery...
 
Bike is stripped to bare bones, no infestations or nibbling apparent. Totally confused!! But still not at the give up and send it to the robbing Honda shop!! Battery load tested and is spot on. It must be something simple as the bike wasnt disturbed at all since it was run about 5 weeks ago. The garage has been a bit damp with all the snow so that may have upset something. Thanks for all the replies so far.
 
Scotty said:
Only 1.5 volts at the coil when the ignition is on, according to the manual it should be 12v.
Click to expand...

This looks like a good place to start checking the schematic. Keep in mind this schematic is for a '06 ST1300/A, I don't know if/how it differs from the UK version.

It appears that both coils share a +12vdc source protected by Fuse L (Fuse J non-ABS). The full electric circuit is:
  1. Fuse L (or Fuse J for non-ABS) supplies +12vdc (Black/Red wire) to the Bank Angle Sensor Relay (terminal 30).
  2. The output of Bank Angle Sensor Relay (terminal 87) supplies +12vdc (Black/White wire) to:
    • The Fuel Cut-off Relay (terminals 30, & 85).
    • Ignition Coil for cylinders 1&3.
    • Ignition Coil for cylinders 2&4.
    • Purge Control Solenoid Valve.
    • Fuel Injectors for cylinders 1,2,3,&4.
    • Exhaust Air Injection Solenoid Valve.
    • O2 Sensor for cylinders 1&3.
    • O2 Sensor for cylinders 2&4.
    • ECM (2 conductors in the 26-Pole Gray Connector).
    • Service Connector (1 conductor in the 4-Pole Red Connector).
I think the logical methodology would be to check for +12vdc at each of these locations in an effort to determine at what point the voltage drops. Then follow that specific circuit checking for loose, corroded, or damaged components.

On the other hand, since you already know the voltage is low at the ignition coil(s), starting at the coil(s) and working back to the Bank Angle Sensor Relay seems like a reasonable short-cut to the methodical approach.

Good luck.
 
Anna'sDad said:
This looks like a good place to start checking the schematic. Keep in mind this schematic is for a '06 ST1300/A, I don't know if/how it differs from the UK version.

It appears that both coils share a +12vdc source protected by Fuse L (Fuse J non-ABS). The full electric circuit is:
  1. Fuse L (or Fuse J for non-ABS) supplies +12vdc (Black/Red wire) to the Bank Angle Sensor Relay (terminal 30).
  2. The output of Bank Angle Sensor Relay (terminal 87) supplies +12vdc (Black/White wire) to:
    • The Fuel Cut-off Relay (terminals 30, & 85).
    • Ignition Coil for cylinders 1&3.
    • Ignition Coil for cylinders 2&4.
    • Purge Control Solenoid Valve.
    • Fuel Injectors for cylinders 1,2,3,&4.
    • Exhaust Air Injection Solenoid Valve.
    • O2 Sensor for cylinders 1&3.
    • O2 Sensor for cylinders 2&4.
    • ECM (2 conductors in the 26-Pole Gray Connector).
    • Service Connector (1 conductor in the 4-Pole Red Connector).
I think the logical methodology would be to check for +12vdc at each of these locations in an effort to determine at what point the voltage drops. Then follow that specific circuit checking for loose, corroded, or damaged components.

On the other hand, since you already know the voltage is low at the ignition coil(s), starting at the coil(s) and working back to the Bank Angle Sensor Relay seems like a reasonable short-cut to the methodical approach.

Good luck.
Click to expand...

+1 on the short cut.

Since your FI light never comes on it's likely that power is not reaching the FI, as this gets power from the same source as the coils. These are fed from the bank angle sensor relay, so pull that relay and check it's terminals. You should have battery power on one terminal (black-pink), ignition on one other (Black), a near perfect connection to the coils (*) (Black-white) and one to ground (via the bank angle sensor, red orange).

All the wire colours are according to the 04 service manual I got, so I hope they are correct.

HTH,

Dani?l

*: and the FI module, and the fuel cutoff relay etc. etc. etc.
 
Many Thanks guys, just the detailed pointer I was needing to boost my flagging enthuisiasm. Ill get stuck in again tomorrow. My bike has had the ground cap recall and that side looks ok. 1.8 ohms to the battery which is good.
 
Scotty said:
Checked the earth point that was subject of the recall and its a good 1.8 ohms. The pink connector seems ok as well. Carl thanks for the link i'll chase through it tomorrow. All of the rest of the electrics and the panel are working fine.
Click to expand...

A good ground would be .001 You have almost 2 ohms resistance to ground, and there are a few ECM grounds that pass through this connector. I would clean that connection and get the resistance value as low as possible to eliminate that as a problem.
 
I was thinking about suggesting removal of the ECM connectors and doing some testing, but I have an even better idea. The diagnostic connector under the seat has 12V on one of its lines that's sourced from inside the ECM, but I forget which it is. The Green/Orange wire is ground, so it's one of the other three. I'd turn the ignition on and check for 12V on the other three pins.

If you don't see it, the ECM might not be getting power, and you should track down the corresponding line on the ECU's main connectors and make sure that's getting fed properly.

If you do see it, that might spell bad news for the ECM, and it's time to start doing the service manual's diagnostics for zero blinks.

--Mark
 
Seems like all the angles are being covered my friend so all I can offer is best of luck to you...I'll be following the thread to a hopefully good conclusion.
 
Scotty I am wondering about the ground also. You cannot measure the ground resistance with the battery hooked up, there is voltage on the circuit because of things like clock memory etc. Without the battery hooked up you should measure less than 1 ohm resistance. A voltage drop test on the ground circuit while it is under load is a far better test to run. With the ignition on place one end of the voltmeter at the fuel pump ground connector for instance. Place the other voltmeter lead at the negative battery post, not the cable but the post, and read the voltage. The voltage must not read above .5 volts. If it does you have a high resistance between the two points in the circuit that the voltmeter is connected to. I hope this helps. A circuit can check good with an ohm meter, which puts very little load on the circuit, but when you put higher current to the circuit it may fail due to a poor connection, missing strands of wire etc.
 
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