Wildguzzi.com
General Category => General Discussion => Topic started by: fubar guzzi on May 09, 2020, 11:47:34 AM
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:weiner: 98 EV runs rich why??? bout everything has been changed cleaned or replaced,I don't know whats left to do! Checking mileage 6/10/12 mpg-----black soot lots of. Will do a 100mph in fourth,but runs crappy under 4k rpm---hard on plugs (very) replaced tps reset to 98 model specs,not much difference there! 9months in my shop ,bout 100 miles I suffered through. Because I pumped (many times) fuel into the oil I changed oil 6 times,thinking there was oil build up in the exhaust I changed out the mufflers to no effect.Suggestions are welcome-------- Anyone have a GUZZI that's been infected by----- 19????? I love my GUZZI(the other 5 of em) :bow:
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TPS bad or still set incorrectly.
Regulator bad and fuel pressure too high.
Trim pot on ECU set poorly or damaged.
Plugged air filter.
Is the problem in both sides (are both plugs wet/black).
GuzziDiag might help by indicating the TPS degrees and the injector open time.
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It sounds as if your computer thinks that the engine is always stone cold and never warms up after starting. The 98 EV has several sensors which can trigger excess fuel. You can remove and test each of those sensors for accuracy.
Engine oil temperature sensor in the left valve cover.
Ambient air temperature near the steering head.
If the sensors test good, then it could still be connectors or wiring faults.
Have you downloaded and installed 'guzzidiag' to a laptop. Easy and cheap the get the cables. Software is free. You can't use the software to adjust anything like you do on more modern Guzzi, but you can display the readout details for any of these sensors.
Have you connected and tested the stock, on-board diagnostic tool? There is an LED lamp near the battery and also a spare connector which must be connected. It is a VERY crude tool and only reports a few faults, but it might just steer you to the bad sensor. I have found several fault problems this way.
Ultimately, it could be a computer fault, but those are exceedingly rare.
Patrick Hayes
Fremont CA
two 98EV, each at 100K miles
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It sounds as if your computer thinks that the engine is always stone cold and never warms up after starting.
^^This^^
Most EFI systems I've encountered default to an engine or intake air temp of -40, which will definitely make it run very rich.
Check for an open circuit in the temp sensor(s) or wiring.
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Fubar. I’m also liking the theory about the engine temp sensor not working correctly. On my V7 I once had the connector on sensor come off and immediately got terrible gas mileage.
I’d make sure the sensor is screwed in snugly to the head, and that the electrical connector is clean and well secured.
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Things can get interesting if the temp sensor fault is intermittent.
Engine runs fine, suddenly loses power and starts belching black smoke, then runs fine again.
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I’d make sure the sensor is screwed in snugly to the head, and that the electrical connector is clean and well secured.
Hope to avoid confusion.
The OP has a 98EV. On that model, the left valve cover has an attached thermal sensor which penetrates into the rocker arm air chamber. Gets splashed with oil and so reports engine oil temperature. Careful! They all leak and the two screws are OH-SO-EASY to strip out threads from the valve cover.
The later big blocks and the small blocks have a sensor that screws directly into the cylinder head casting and so reports head metal temperature. Early ones used a plastic housing which had a tendency to crack with age and heat and allow the sensor to come loose and report false cool temperatures. Brass replacement is more durable.
So, on this 98EV bike, the 'screwed in snugly' comment doesn't really apply and could be a source of damage.
Patrick Hayes
Fremont CA
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:bow: Thank you one + all for your advise,I will follow up as time permits. Wayne,can't use GUZZI Diag (98 model)---Both sides of exhaust are black/sooty----air filter is ok---ecu set correctly (250 mv which =o)----regulator for fuel,I know nothing about,please enlighten me!!! TPS brand new(ca cycleworks) set perfect---
PEHAYES----engine oil sensor replaced (plastic)----ambient air temp replaced-----I will go through wiring,again!----cannot use GUZZI Diag only multimeter-----led lamp is no go,can I replace led lamp with multi meter?
Nc43 I will check for open circuit in temp sensor,again.
SMITHSWEED---will check + thank you
NC43 How do I locate a metal temp sensor?
PHayes---I've replaced plastic sensor with same where do I locate a brass one?
:popcorn:
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GuzziDiag works fine on my 98EV. Besides the LED there is a socket w/cap on it. Wires plug right in.
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If you have a 98 it's in the rocker cover and nothing else is available as far as I know. we used to wire in a resistor to fool them to run leaner because it then thought the oil was hot.
250 MV? where did that come from. the TPS can be set from dead closed at 150 I think. but the 98 was 375 at idle again from long ago memory. when you turn the key on does the fuel pump run for a couple of seconds then shut off?
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on my '99 I wired a switch with a resistor that tells the ecu the engine is either cold in which case it gets its signal from the temp sensor or hot where it goes through the resistor. I looked up the chart and used a resistor that matched one that I think was fully warmed up. I use it like an electric choke, it wont start cold until I flip the switch. once warmed up it runs the same either way but gets better mileage if I tell the ecu its full hot.
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Wayne,can't use GUZZI Diag (98 model)---Both sides of exhaust are black/sooty----air filter is ok---ecu set correctly (250 mv which =o)----regulator for fuel,I know nothing about,please enlighten me!!! TPS brand new(ca cycleworks) set perfect---
Sure. Guzzidiag works fine on the P8 to display the sensor information and such. You just can't reprogram the EEPROM, but that doesn't matter.
It will tell you if a sensor is way off anyway. Great info, and cheap.
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Thanks Patrick. I did not know how much different this engine temp sensor is. Looks like a really crappy design.
But Fubar. I’m still suspicious of this sensor or its related electrical connectors.
Otherwise, is fuel pressure way too high? Blocked pressure relief valve?
Are the injectors themselves sticking open? Seems unlikely that injectors on both sides would be bad.
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Thanks for all the reply's,I thought I was alone on this but our Guzzi family has come together for me---thats great,now I really need to borrow $50.---ok no more jokes----guzzisteve,I am with the believe the 98 cannot be connected to the Guzzi Diag so---because you use it I shall check it out .
Vagrant, I'd like to know more about the resisitor thing----on my bike for what it's worth the ecu runs 500/o mv, so250 would be half way or o between rich+lean----please tell me I'm wrong,so if that's how it is why not set it at 125 mv to make it lean? Fuel pump is fine.
John A,Help me with information I'll do it ! :boozing:
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Like Wayne says you can't re-map it with GuzziDiag but you can see what it's doing. I would turn the idle trim back 1 turn and see if it does anything. You can always move it back, just make a note where it was.
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Fubar!
You say the TPS is new but did you install it? It has to be carefully calibrated to the throttle, from Idle, Because the place where it tells the ecu that you are at full throttle is important. It should be linier to some point the got to max mv telling the ecu to go rich, like going to the main jet on a mechanical carb.
This is the case on my beemer but they all are very similar.
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Like Wayne says you can't re-map it with GuzziDiag but you can see what it's doing. I would turn the idle trim back 1 turn and see if it does anything. You can always move it back, just make a note where it was.
It is my understanding that the tiny trim screw inside the ECU is only effective at idle. That particular input has no relevance on the fuel mapping at higher rpms. You can lean/rich the idle mixture but it has no effect above idle. This particular bike is running very rich throughout its range so something else is at play here.
Patrick Hayes
Fremont CA
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OP's comments in red.
Wayne,can't use GUZZI Diag (98 model)
Yes you can. GuzziDiag has two functions. One is to report out all sensor data and the other is to adjust the ECU map. On the 98EV you can NOT make any adjustments. But you sure can read the data output. And like this case, it can be a huge help.
ecu set correctly (250 mv which =o)
You'll have to carefully explain this one a little further. The ecu = the big computer box under the seat. Nothing is adjustable except for idle mixture trim and completely swapping out the map program EPROM. I suspect you are referring to the TPS or Throttle Position Sensor. That one is adjustable and it is VERY, VERY sensitive. Typically, all the linkage is disconnected and idle stop screws backed out completely. Then the TPS is adjusted so that it reports 150mV up at the huge gang connector on the ECU. Once the linkage is all reconnected and the bike is running, that same setting will now report out about 385mV.
TPS brand new(ca cycleworks) set perfect
No it is not. See above.
cannot use GUZZI Diag only multimeter
Yes, you can and should. Your problem is a sensor or wiring fault and this is the best way to find it.
led lamp is no go,can I replace led lamp with multi meter?
Please explain "no go". Is it missing? You don't know how to utilize it? It is hidden in the battery compartment and not easy to find. There is a loose plug cap hanging nearby. Plug in the loose cap, turn on the key, but no start. The LED will flash a series of codes repeatedly. You count the flashes and pauses and report back. It only reports a limited number of issues. It doesn't 'store' codes so it only reports currently active failures, not intermittent ones. See here:
(https://i.ibb.co/0XxYRsh/MVC-252-Lx.jpg) (https://ibb.co/0XxYRsh)
I will check for open circuit in temp sensor,again.
This is why you need to utilize GuzziDiag. In order to test a sensor you have to disconnect it and use a meter. Tests good. What it doesn't tell you is the quality of the connector or the downstream wiring. Good sensor can be ignored by wiring faults elsewhere. GuzziDiag gets its information from the ECU computer. So, it not only tells you that the sensor is good, but that all the subsequent wiring is good as well. If it reports bad and you swap out another sensor and it still reports bad, then you can be highly suspect of connectors or broken wiring. Good luck with that one!
How do I locate a metal temp sensor?
You don't. That is for newer models. Guzzi learned their lesson. You're stuck with what you have.
I've replaced plastic sensor with same where do I locate a brass one?
See above. Sorry.
Patrick Hayes
Fremont CA
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pehayes explained it very well above. the .385 is easy to check with a good multi meter just remember to have the fast idle lever off and throttle off. I always found it easiest to do with the engine off. it's touchy aas hell to set and changes when u tighten it down. more importantly it is different on the 98 as compared to a 2000 and up so use the settings above. as for the resistor it's too long ago to remember but I suspect this old tractor might still have info on it. made a big difference in cold weather as the engine oil hitting the stupid sensor in the rocker box wasn't hot enough to change the mixture. but at your MPG you have another problem.
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Forget about the resistor temp sensor tweak for now.
You have something BROKEN. Once you fix it, you may want to think about the resistor tweak.
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:bow: Good morning all,happy M-day(all you Mothers)----I think the first step is Guzzi Dia.,I know nothing about GD so I must start somewhere. I contacted beetle + he set me straight about GDiag-----so,now I will read up on GDiag.+start this mind boggling process,at least to me it is mind boggling!!!!
:popcorn:
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Hey Fubalator, sorry you're having trouble. Remember, ACE is the PLACE! Just a short road trip to old St. Joe!
(https://i.ibb.co/Gcjffr2/jesse-james.jpg) (https://ibb.co/Gcjffr2)
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on my '99 I wired a switch with a resistor that tells the ecu the engine is either cold in which case it gets its signal from the temp sensor or hot where it goes through the resistor. I looked up the chart and used a resistor that matched one that I think was fully warmed up. I use it like an electric choke, it wont start cold until I flip the switch. once warmed up it runs the same either way but gets better mileage if I tell the ecu its full hot.
Hi,
Do you have link to instructions on how to wire this up?
Thanks