Barely alive II

[czakky]

Picking up where we left off....

 

Idle dies when warm (twenty plus mins. run time) after recent maintenance including:

Wire harness grooming

airbox/air temp sensor grooming

front crank seal replace

grooming fuel pump power supply/coil power supply

timing sensor o-ring replacement/wire leak fix

 

Valves/TPS are in spec

Fuel filter is new

air filter is new

lotsa' insulation round my external fuel pump/lines

fuel tank breather lines seem to be kink free

 

Kiwi_Roy sent me an awesome resistance test chart through the ECU and everything seemed fine there.

 

The only thing left that the board had recommended for me to check was the injectors themselves...

 

Which probably won't get done for a few days. I have been reading "Guzziology" for the last week or so and have noticed that some of my symptoms are similar to advanced timing... Thoughts? My bike has from day one (in my ownership) sounded like there was some rattling going on when the throttle is rolled on hard under load only at certain speeds/RPM. Nothing too noticeable but audible through a helmet.

 

Throwing some more info out there into my abbreviated recap of a lost thread. Sorry if this is confusing and thanks for any help.

[fotoguzzi]

fuel tank breather lines seem to be kink free

 

do you have tank suck when you pop the filler? is the tip over valve in place and oriented right? if there is one?

 

I don't buy the both injectors bad at same time..

 

still have the charcoal canister hooked up?

[czakky]

Hey Foto, no tank suck I checked it a few times when I was having problems.

 

about the injectors I don't really either but I'm running out of things to check.

 

No charcoal canister was removed shortly after I bought her, I did recently "Y" the fuel lines together but like I said no noticable tank suck.

[Kiwi_Roy]

I mentioned that your air temperature reading seemed very high 30 odd Ohms about 140 °C, is it in a cool air stream?

 

I would also check that you are not loosing Voltage to the ECU relay but that usually causes the bike to miss and fart

         Dirty ignition switch or sidestand switch

 

Check you are getting a full pipe flow back to the regulator, just slip the hose off and put it in a bottle while the bike primes

         Is the pump extra noisy

[czakky]

Roy, the 30 ohm reading was after a ride as soon as I could get a reading just to check that it was dropping resistance.

 

Will check ECU voltage

 

I can check that too. Any amount specifically that should flow? Can't remember last time I accidentally checked that....

 

The reason I had cleaned the contacts on the fuel pump is because every tenth or so time the pump primes it makes a weird sound usually half way through priming. After cleaning the contacts (again) it seems to be doing it less but still occasionally. It's always done it and besides the noise there has never been an issue.

[Kiwi_Roy]

The ECU relay might be dropping out because of a bad connection/contact. I encourage guys to add a light to the wire feeding the relay so they can watch for it dropping. A convenient spot to pick this up is the petcock fuse, a little lamp between there and chassis taped to the bars is all you need. It should never so much as flicker.

 

Weird pump sound, could it be the internal relief lifting i.e. blockage going forward, the pressure goes from 45 to over 60 psi and the fuel flows back thru the hollow pump shaft.

 

Here is the full chart for thermistor

Why was it so hot or were you measuring the oil temperature, air temperature should read over 1000 Ohms = 50°C 30 Ohms is in the stratisphere (ok, I can't spell)

 

 

[czakky]

To test the ECU I should wrap some wire around the fuel pump fuse? To a small bulb like from a turn signal or the like?

 

Guess I am not sure how to measure PSI at the fuel pump. If I understand the fuel pump system on these bikes the fuel pump works like an air compressor only running when pressure is needed?

 

The air temp sensor is right where Luigi put it. Whe I got the 34.5 reading it was probably around 72f/22c so nothing extreme bike had died a couple times and was just through some stop n go traffic. Don't know why resistance is so low. There is a very minscule tear on the red coating of the element on the actual sensor. Its always been there and never gave it much thought.

[fotoguzzi]

 

Guess I am not sure how to measure PSI at the fuel pump. If I understand the fuel pump system on these bikes the fuel pump works like an air compressor only running when pressure is needed?

 

 

no, the pump runs continuous (once running) and had a regulator to maintain pressure, extra fuel is pumped back into the tank.

[Kiwi_Roy]

 

 

Guess I am not sure how to measure PSI at the fuel pump. If I understand the fuel pump system on these bikes the fuel pump works like an air compressor only running when pressure is needed?

 

 

no, the pump runs continuous (once running) and had a regulator to maintain pressure, extra fuel is pumped back into the tank.

 

Just to add to that, if anything blocks the path to the regulator e.g. a dirty filter the pump pressure will build up to about 60 psi then relieve back internally. I believe on your bike the regulator is fitted under the RH side of the tank, the pressure in that hose is 45 psi set by the regulator from memory, it's the same pressure the injectors see. 

To measure the pressure you have to tee in at that point.

It's unlikely the regulator has failed but if you pull the hose off and direct it into a bottle you should see a full pipe, not a dribble while the pump primes.

I don't understand how your new filter could be blocked but the symptoms, dying at higher revs and fuel pump noise seems familiar, it will only take a minute to verify the flow. A word of caution, when you take the hose off some fuel will squirt out because the system normally holds a bit of pressure.

 

No, not the fuel pump fuse, the electric petcock fuse, it is on the same wire that powers up the ECU relay, the power must remain on at that point or it will play havoc with the ECU. It's quite common to have a dirty switch drop it out. Yes any small lamp will do although I prefer a 12V LED, I have one that fits inside the pivot point for the levers

 

I just sent you a PM

[docc]

Wouldn't a 30 Ohm resistance on a sensor that should be 3,000 Ohms at that temperature say that sensor is "bad?"

[czakky]

Docc, that is a hot engine. So sorta bad...

 

Ok first thing Roy is I'll check flow which I'm pretty sure is good . Then onto the petcock fuse which I do have a manual one on there so thus my confusion. Just to verify my bike is actually stable at higher revs but dies when idling down and then loses power until up into the 3k range when well warmed. Got the PM

[docc]

The "electric cock" fuse slots are in the very back of the row, #8. You could simply pull that 5 amp out (if there is one) since you have a manual cock. As God intended.

 

I get that the air temperature in the airbox could have been higher than ambient, but not likely even close to engine oil temperature (what, like 200-250˚F/ around 100˚C).  Extrapolating off the bottom of Kiwi_Roy's chart suggests your sensor is signaling for 170-175˚C (almost 350˚F). You could bake a pizza in your airbox.

 

Have you checked the resistance on that sensor with everything cold (ambient)?

[czakky]

I suppose then Docc that I could just short a wire across the contacts to the said tester bulb? 

 

I just wasn't sure if you knew that it was a hot engine. I'll check it cold again but last time it read normal I believe.  Something tells me I need a new air temp sensor.

 

Couple more tests first. Besides, I wanna ride around with a bulb taped to my dash.

[docc]

If I understand Roy correctly, yes you can simply wire a bulb (or, better, LED) across that blank fuse holder and monitor for flicker.

 

Another nice thing about the LED is you can run the wire up your sleeve and tape the LED inside your face shield.   (really, don't)

 

I'm usually in the 'something came unplugged, bad connector camp', but if you can't get a normal resistance in that temp sensor - it's played up. Check it at ambient and warm it with a hair dryer looking for the change.

[Kiwi_Roy]

I sent you a sensor but in the meantime you could just go to Radio Shack and get a normal resistor roughly equivalent to the air temperature

2.2k Ohm ~ 30 degrees C would be close enough to try, I doubt the air temperature is that critical

 

For yours to read so low I think it must have some sort of short, I'm not sure what action the ECU would take if it thinks the engine is that hot.

You weren't reading it with the ECU plugged in by any chance?

 

When I put pods on my bike I figured it would be too hot under the tank so I relocated the sensor up by the headstock in the cool air.