Hi This was some replies from
http://www.bmbikes.org.uk/ forum.
I thought it might be of some interest. I feel like I might be gettting a bit closer.
Cheers Duncan - see below
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hi, welcome, where in scotland are you based?
i can not help, I think i would be ok with the coil resistances.
if you have sparks and fuel at the right time i would expect it to start, since you have both I wonder about the time, could you have mixed up the lead order between the 5 minute stabilisation and the Not Running chang?
which manual do you have? IIRC the factory manual has been made available on the web which may have more help
george
Member 21, R100R, K75 and a Hyosung 250 FOR SALE
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User avatarGalactic Greyhound
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Fuel Pressure Test procedure, Coil Resistance and general troubleshooting?
Postby Galactic Greyhound » Wed Aug 24, 2016 9:15 am
Hi Duncan,
Welcome to the forum!
The Fuel Pressure should be maintained while the engine is rotating and will fall to zero within 2 seconds of when the engine stops.
The Fuel Pump does not run until the engine is turning over as the Electronic Ignition Module needs the HES signal from the Ignition Trigger Unit that the engine is rotating before it will operate the Fuel Pump relay which switches on the Fuel Pump.
This why the Fuel Pump stops delivering pressure when you stop cranking over the engine.
Can you measure the Fuel Flow rate on the Regulator Return Hose - it should be 2 litres/minute.
Do this on a pro-rata basis of cranking for 15 seconds and expect to see 500cc of fuel delivered from the return hose.
Use a clean, clear 2 litre plastic bottle (coke bottle) to measure the return flow.
Check for the presence of water in the fuel returned.
Keep your Battery well charged as the cranking will flatten it.
The Fuel Regulator controls the Fuel Pump pressure which should be around 40 psi on the Injector Fuel Rail.
I would not be concerned about the 100psi Fuel Pump pressure at the moment but there is a risk in leaving it as it is.
There is a pressure limiter in the Fuel Pump which opens at 65psi as per Bert Vogel's Troubleshooting Procedure as per your link.
The Fuel Regulator drops the pressure to that required by the Injectors of around 40psi.
The Fuel Pump pressure limiter valve may be stuck closed and worth a look next time you take the Fuel Pump out.
I don't think that this is the cause of the non-starting but there is a risk that the higher Fuel Pump pressure will rupture the Fuel Hoses, Fuel Filter or Fuel Regulator.
Any rupture should show up when doing the Fuel Return Flow test described above.
When testing the bike, leave the Fuel Filler Cap cracked open in case there is a failure of the Fuel Tank venting causing a fuelling problem.
Check that you have not knocked a lead off one of the sensors when working on the bike. A disconnected sensor can prevent the bike from starting.
The EFI needs to know the ambient temperature and the water coolant temperature in order to set the correct (rich) air/fuel ratio when starting from cold in order that the bike will start.
The ambient temperature is determined by the Air Temp Sensor (ATS) in the Air Flow Meter.
The water temperature is determined by the Water Temperature Sensor in the cylinder water jacket - note that this sensor has TWO negative resistance elements and therefore TWO leads are connected to it.
Have you tried dis-connecting the Idle Switch? (see Troubleshooting Page 8/30 - Idle Switch).
Is the Vane in the Air Flow Meter free to move or is it stuck in one position? (see Troubleshooting Page 10/30 - Air Flow Meter).
Is the Air Temp Sensor (ATS) in the Air Flow Meter actually working? (See Troubleshooting Page 26/30 - Test of the Air Temp Sensor in the Flow Meter).
The bike may not be firing because of an incorrect fuel/air ratio being supplied. Measure the resistance of the ATS at ambient temp and then see if it changes using an ice pack/hairdryer.
At cranking speeds, the ATS provides the data for starting fuel/air ratio.
Can you measure the change in resistance when the Air Flow Meter vane is moved? (See Troubleshooting Page 25/30 - Testing the Air Flow meter).
Note that the Air Flow Meter potentiometer data is only sent to the EFI Controller above 900 rpm but if there is a break in the potentiometer circuit or the Vane is stuck it may be affecting the Start Up fuelling.
Have you checked the resistance/temp of the Water Temperature Sensors (WTS)? (see Troubleshooting Page 18/30 - Water Temperature Sensor).
The Water Temperature data is used by the EFI along with the Air Temp data to set a rich Air/Fuel ratio that the bike will start easily.
Your initial post indicated that the bike was NOT previously starting very well so these sensors (ATS and WTS) need to be checked out.
From your initial post it would appear that the Air/Fuel Ration was too lean on starting from cold in that the engine was having difficulty starting until it got warm and the supplied (lean) Air/Fuel Ratio then became adequate to keep the engine running smoothly.
When switched Off and cooled down a little, the lean mixture caused re-start and running problems until the engine got up to normal running temperature again.
NOTE: The bike will NOT start if the water temperature is above the normal range of operation. A bad temperature sensor will send the wrong Water Temperature signal to the EFI which can prevent starting.
The Water Temperature sensor has TWO resistance elements - you need to check the resistance of BOTH of these resistance elements from their terminals to earth.
You should expect to see 2,500 Ohms to earth on each element at a Water Temperature of around 22 deg C.
The resistance will FALL as the Water Temperature rises so that you might expect to see a resistance of below 500 Ohms at normal running temperature.
If you spray EASY-START (ether) into the air intake and immediately try and start the bike then it should fire once or twice if the Ignition System is working.
If it does, then the Ignition System is likely OK and the fault lies in the Fuelling.
If it does not, then the Ignition System is suspect.
You can FORCE a rich Air/Fuel mixture by covering the air intake with a gloved hand (in case of flame blow-back) when starting and see if this will induce the engine to fire.
I am very suspicious that the plugs are not sparking or are sparking incorrectly.
Have you got the plug leads connected in the right order as George has suggested?
The HT coil resistances look OK.
However, be wary of using a spark plug tester to determine the HT status.
The neon type of HT tester is misleading as it will produce a flash at very low HT voltages which are not sufficiently high to produce a spark at a plug.
You need to observe a spark at a plug, ideally using a Test plug which has a gap of 5mm.
I cut off the outer earth electrode to make a Test Plug leaving just a sharp point on the side to create the 5mm gap.
The sharp point aids the HT to jump the gap to the centre electrode.
Use a short earthing lead with large croc clips each end to earth the plug body to the engine casing as either yourself or the electronic high-energy ignition system can be damaged if a plug body is held by hand and/or not fully earthed.
Keep this Test Plug and its short earthing lead safe on the bike for easy testing while touring.
The spark observed MUST be coloured BLUE (high energy) or it may not spark under compression.
A red or yellow colour spark is no good and indicates a faulty ignition system.
You might also check the compression on each cylinder.
IN SUMMARY:
There are two areas that need to be checked out as above:
1. The Air/Fuel Ratio is incorrect. It should be rich for a cold start in order for the engine to fire up.
2. The plugs are not sparking or have a weak spark which is extinguished under compression. Try using Easy-Start (ether) to prove the Ignition is working.
Please put your location in your profile as it helps with meets/assistance etc.
Ced.
R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons - It works!
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hmmmya
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Re: Fuel Pressure Test procedure, Coil Resistance and general troubleshooting?
Postby hmmmya » Thu Aug 25, 2016 2:23 pm
Thanks for comments George.
I’m based central Glasgow. Lead order I feel is correct, since I’ve been anal some time ago and numbered them.
This said, Im double checking everything at the moment so will make sure I’ve not been a dafty.
Thanks Galactic,
Understood re the fuel pressure, this makes sense and I’m pleased you’ve clarified this.
Battery is strong but will keep an eye on it. I have been tempted to take it to a garage and get a load test done on it just to be sure, I’ll put this on my to do list.
Fuel pressure at the rail has been measure on 2 occasions and is consistent at 35 psi
I have tested the bike with the bike fuel cap open and no change. I’ll continue to test with cap open to eliminate possibility for now.
Regarding Sensors I have checked temperature sensor interms of connections and tried disconnecting the throttle sensor but haven’t fiddled with the airbox yet so I will check leads are fully home. With this in mind any checks in the airbox mentioned I’ll put on my list.
Regarding your comments on air fuel ratio
“When switched Off and cooled down a little, the lean mixture caused re-start and running problems until the engine got up to normal running temperature again”
This symptom would happen even if I turned the bike off for 1 second and started it back up again, in my head there would be very little time to cool down. I feel this symptom is significant somehow but not sure if it quite makes sense with your comments, do you agree? I will none the less measure sensor resistances on both temp sensors.
I will buy some Easy Start, this has been on my mind to try but hadn’t thought that it could be used to eliminate/diagnose fueling or ignition. This is a very useful tip.
Thanks for the comment on Spark tester. I bought 4 of these
http://www.ebay.co.uk/itm/Sparkrite-Spa ... Swn9lXKwBg
so I could visually see all four working whilst cranking. Are these the neon type? They all appeared a good consistent brightness however as its red translucent plastic, colour is not obvious.
It’s worth noting I did hold each plug up the engine previously and I was finding inconsistencies which made me think I wasn’t doing it right and so I bought the 4 testers. I will definitely try and knock up a test plug as suggested.
My HT leads are 1 year old (
http://www.realmengineering.com/ram%20p ... leads.html) I swapped these out to try and eliminate problems with leads, I swapped them with my old HT leads (33yrs old) which still worked when I replaced last year. No difference and now new ones are back in.
I will check compression on all cylinders but I need to buy a tester.
Thanks for the useful input, it’s been starting to do my nut so it is great to get some extra thoughts which will keep me busy.
I’ll give you an update and/or pick your brains again with the outcome.
Below is my to do list in order of quick checks then priority. I've also purchase a second hand pair of coils earlier in the week so I might see them tomorrow but I do these checks first.
To do list
Double check lead order
Check air box sensors connections.
Easy start test
Test plug test
Check free movement of air box vane and correct resistance
Check resistance of Water temp sensor (only 2 years old but worth eliminating)
Test compression
Battery Load test.
Measure flow rate from regulator return (if not 2l/min I can assume a ruptured hose)
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hmmmya
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Re: Fuel Pressure Test procedure, Coil Resistance and general troubleshooting?
Postby hmmmya » Thu Aug 25, 2016 7:50 pm
ok,
I've checked the HT lead order and its definitely correct.
Air box sensors connections are also fine.
I sprayed Easy Start into the air box with 2 shortish spurts behind the air filter with no difference.
I also sprayed to short bursts in front of the filter with no difference to engine. I didn't want to be too keen with this stuff since not used it before.
I held my handover the air box inlet to try and force a rich mixture but with no difference to it starting either. Worth noting that I didn't feel any suction on my hand either, however I think I have not noticed anything pull/suction in the past either even when the machine is operating well since I've done similar tests in the some years ago. Would this be correct?
I will finish off doing the remainder of my to do list on Monday as I'm out of town.
With out getting ahead of myself, I guess I'm now leaning towards a faulty ignition system.
I have a set of cheap 2nd hand coils turning up soon thanks to ebay. However since the resistances are fine on the originals I suspect these might sit on my spares shelf in the long run.
The spark plugs are new
The HT leads are nearly new
The Hall sensor I replaced 2-3 years back
Which makes me think the Electronic Ignition.
Galactic, may be you are right and I have damaged it previously when trying to earth the spark plugs by hand against the cylinder head...
Hmmm food for thought. Either way I will continue with my to do list since there was the original problem which maybe caused by sensors.
Are those sparkrite testers a waste of time? I will be annoyed if they have sent me on a wild goose chase.
Thanks again for your time.
