Author Topic: Fuel Injection FI Issue  (Read 3117 times)

Offline Karl Von

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Fuel Injection FI Issue
« on: April 25, 2015, 07:29:56 PM »
Hi All
I am working on a 98 centauro that has been sitting for about 3 years. The bike has less than 3,000 miles on it.
I am having trouble getting the bike running. All findings point to the fuel injection system. The fuel pump is getting fuel and pushing it to the injector body. The Injector bodies and spark plugs are dry. I checked the voltage of the plug going to the injector and it is showing 12 volts. I have replaced all the fuel lines and installed a new fuel filter.

The only thing I can come up with is the injectors might be plugged up. Besides soaking them in carb cleaner, does anyone know a way of cleaning these or know a possible automotive replacement for the injectors ?

Vasco DG

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Re: Fuel Injection FI Issue
« Reply #1 on: April 25, 2015, 07:35:24 PM »
Take them to a place that services injectors and get them cleanes ultrasonicly. Before you do that though hook up a diagnostic tool and test the injectors in-situ. You'll be able to hear them firing if they are and if the inside of the inlet manifolds are wet you'll at least know that fuel is being delivered. No guarantee though that the patern or quantity would be correct.

Pete


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Re: Fuel Injection FI Issue
« Reply #2 on: April 25, 2015, 07:39:04 PM »
does it still have the original Siemens relays? first thing I'd do is replace every one of them.
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Vasco DG

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Re: Fuel Injection FI Issue
« Reply #3 on: April 25, 2015, 07:40:09 PM »
does it still have the original Siemens relays? first thing I'd do is replace every one of them.

Good call!

Offline Karl Von

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Re: Fuel Injection FI Issue
« Reply #4 on: April 25, 2015, 07:43:08 PM »
The relays have been replaced and are fine.  The relays are for the fuel pump, ECU, Starter and lights.  All are working fine.  The inlet tubes are bone dry but there is fuel under pressure in the lines going to the in injector units.  I will see if someone locally can clean them.  Hopefully they are just plugged from sitting for 3 years since last cranked.

Online Kiwi_Roy

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Re: Fuel Injection FI Issue
« Reply #5 on: April 25, 2015, 09:08:06 PM »
The fuel circuit goes tank - pump - filter - injectors - regulator and back to the tank,
Pull the line off where it returns to the tank and make sure you get a good flow into a bottle.

I have a really good document on the fuel injection. PM sent
« Last Edit: April 25, 2015, 09:09:39 PM by Kiwi_Roy »
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Offline Karl Von

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Re: Fuel Injection FI Issue
« Reply #6 on: April 26, 2015, 01:46:00 PM »
getting plenty of fuel back to the tank mounted regulator, so my next step is removing the injectors and getting them serviced.  Hopefully that will fix the problem

Offline Charles in Lake Charles

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Re: Fuel Injection FI Issue
« Reply #7 on: April 26, 2015, 02:13:53 PM »
When I got my Centauro, it had been sitting in a dealer's shop for a couple of years. As is pretty common, it didn't run that smooth. After a different chip, it ran better.  Two years ago it started to run really bad on one of the cylinders. I pulled the injectors and sent them to Mr. Injector http://www.mrinjector.us/. When I got them back, both were partially plugged with one only flowing about 60%. I replaced them and now it runs like a charm. I just rode it today and it's as smooth as you can expect from a "Beast".
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98 Yellow Centauro, 93 SPIII, 1978 LeMans
1977 Convert, 1975 850-T (FOR SALE)
1985 Harley FLTC, 1985 K100RT
2001 Lees-ure Lite Camper

Online flangeman_70

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Re: Fuel Injection FI Issue
« Reply #8 on: April 26, 2015, 02:23:54 PM »
Before removing the injectors, make sure you have spark. If you don't, it is likely the cam phase sensor that a) has a contaminated plug, b) is out of adjustment or c) is dead. It should read about 680 Ohms.

The relay call is valid. Try interchange them.  Mine had the issue. I'd be riding along and then dead, roll to a stop and crank until the cows came home but no start.measure voltages and resistances, all ok. Change relays and then run perfectly. I opened up the relays and found that the switching arm was completely bent (on more than one and one various types) so there was voltage but it couldn't carry current.

Look on Centauro Owners Group as there is a load of documented issues with the blasted things ~;
I love mine! It has just broken the cam phase sensor >:(Guess what? No spark, no fuel, no go!
Parts are on the way  :bike

Regards,

Adam
You only went to school to learn how to learn

Adam

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V10 Centauro 1996

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Re: Fuel Injection FI Issue
« Reply #9 on: April 26, 2015, 03:39:55 PM »
When I got my Centauro, it had been sitting in a dealer's shop for a couple of years. As is pretty common, it didn't run that smooth. After a different chip, it ran better.  Two years ago it started to run really bad on one of the cylinders. I pulled the injectors and sent them to Mr. Injector http://www.mrinjector.us/. When I got them back, both were partially plugged with one only flowing about 60%. I replaced them and now it runs like a charm. I just rode it today and it's as smooth as you can expect from a "Beast".

Was wondering is this "Mr. Injector" offered to make this good after sending back the bad units?

Offline Charles in Lake Charles

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Re: Fuel Injection FI Issue
« Reply #10 on: April 26, 2015, 03:52:50 PM »
Poorly worded on my part, they sent back the cleaned units.
MGNOC # 8115:
98 Yellow Centauro, 93 SPIII, 1978 LeMans
1977 Convert, 1975 850-T (FOR SALE)
1985 Harley FLTC, 1985 K100RT
2001 Lees-ure Lite Camper

Offline Karl Von

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Re: Fuel Injection FI Issue
« Reply #11 on: April 26, 2015, 04:13:16 PM »
I am getting plenty of spark and 12v to the injectors and the fuel pump is working fine., so i believe the relays are ok. I assume the ECU relay would also control the coils / spark and voltage to the injectors, which I am getting both.

Now the fun in trying to get the injectors out without breaking any of the plastic pieces or stripping the 6mm Allen head screws that have been loctited in the throttle bodies.

Offline rodekyll

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Re: Fuel Injection FI Issue
« Reply #12 on: April 26, 2015, 04:28:05 PM »
Karl, just to be sure -- the small spigot on the pressure relief valve is open to air?  Nobody attached a hose to it or plugged it?

Have you been able to verify fuel pressure?  The pump can work but not get the rail up to pressure.

Have you tried a shot of ether (starting fluid) in the TBs?  That would tell for sure that it's a fuel delivery thing (although not why).

The injectors should click when they fire.

Someone mentioned the sensors might be dirty.  If this is a P8 injection you have two critical sensors -- one on the cam and one on the flywheel.  The flywheel one in particular can get crudded up.  That will affect timing and injector pulse duration.


I'm mentioning all of this because pulling the injectors can make you say more bad words than checking these things will.   :)

Offline Karl Von

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Re: Fuel Injection FI Issue
« Reply #13 on: April 26, 2015, 06:09:50 PM »
Karl, just to be sure -- the small spigot on the pressure relief valve is open to air?  Nobody attached a hose to it or plugged it?

Have you been able to verify fuel pressure?  The pump can work but not get the rail up to pressure.

Have you tried a shot of ether (starting fluid) in the TBs?  That would tell for sure that it's a fuel delivery thing (although not why).

The injectors should click when they fire.

Someone mentioned the sensors might be dirty.  If this is a P8 injection you have two critical sensors -- one on the cam and one on the flywheel.  The flywheel one in particular can get crudded up.  That will affect timing and injector pulse duration.


I'm mentioning all of this because pulling the injectors can make you say more bad words than checking these things will.   :)

The diaphragm nipple on the regulator is open and clear.  I have not checked the pressure, as I do not have a gauge but when I loosen the hose clamp, a good stream of fuel shoots from the hose.  The bike has the 16m ecu and there is just the one pick up on the cam wheel.  I will give that a look.  I did get the injectors off and they were caked up with a hard white powder residue.  Regardless if they are the main problem, they needed to be cleaned anyway.  I hope they are serviceable, as the last ones I found for sale were 391 Euro's each


Offline pauldaytona

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Re: Fuel Injection FI Issue
« Reply #14 on: April 27, 2015, 03:56:05 AM »
get duzzidiag, then you can use the test functions and check what is wrong
Paul

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