4Rt Only Runs With Fuel Pump Disconnected!

[honda_freak]

What fuel line are you talking about - is the fuel feed hose or perhaps the the fuel return hose !!!

 

Edited December 3, 2016 by honda_freak

[thall1]

the fuel feed line .....item 8

[honda_freak]

It seems like the fuel injector are getting it fuel backwards through the fuel pressure regulator - that's odd.

 

Maybe the fuel pressure membrane are faulty !!!

[jonnyc21]

Sure sounds like the regulator or injector to me as well with that update.

Maybe try some injector cleaner (I like seafoam) in a tank or two and get it running for a good long ride or two and see if the injection issue clears up before replacing parts?

Good luck!

Edited December 3, 2016 by jonnyc21

[chris200]

why would that be an issue? the bike has ran for a couple of years (a few issues over that time

but all sorted eventually) until now with this particular problem....

I don't think that would be an issue either but I do think the reply has been posted on the wrong topic (woody 1 was asking about twin map ptb's )

 

I have a feeling that your fuel pressure regulator is knackered and the excess fuel pressure being delivered is causing the engine to flood .The best way to diagnose this would be substitution with a known good one . If you are near to or in South Wales and could travel to me you could try mine

 

 

[thall1]

its not the injector or the fuel regulator...the unit has been fitted to another bike and it ran fine...Chris200 -

thanks for the offer to use your bike...your not too far away but I have some bikes closer....

Just checked the cam timing-spot on... and using a plunger on the piston the TDC is ok as well...no excessive clearance on one inlet valve to suggest a stuck open inlet valve...

[jimmyl]

Can you swap throttle body?

Have you swapped tank to test this is ok.

Have you checked earth on coil etc. Earth cable can corode and have run extra earth wire to engine bolts .

Can you swap coil.

Bad spark might be leading you down the fuel path.

[thall1]

latest is:

I put my throttle body, injector assy, and fuel tank on a friends bike.... bike started first kick!

just to be absolutely sure I stripped the engine down to piston/barrel... all ok...

now the loom has been stripped back....all earth and positive feed wires have been checked for bad connections/high resistance... again all ok.

I'm now left with stator and coil pickup, capacitor and rectifier...

one question...I have read somewhere that the capacitor 'smooths out' the voltage....I always was thought it was to provide a 12v supply to power the ecu?... Im just wondering if its this that has been playing up and not storing or putting out enough voltage when its being kicked over?

[jonnyc21]

Give it a check?  Good luck...

 

Check & Test a Capacitor By Analog Multimeter ( AVO = Ampere, voltage, Ohm Meter )

1. Make sure the suspected capacitor is fully discharged.
2. Take an AVO meter.
3. Select analog meter on OHM (Always, select the higher range of Ohms).
4. Connect the Meter leads to the Capacitor terminals.
5. Note The reading and Compare with the following results.
6. Short Capacitors: Shorted Capacitor will show very low Resistance.
7. Open Capacitors: An Open Capacitor will not show any movement (Deflection) on OHM meter Screen.
8. Good Capacitors: Initially, it will show low resistance, and then gradually increases toward the infinite. It means that Capacitor is in Good Condition

 

Test & Check a Capacitor By a Digital Multimeter

1. Make sure the capacitor is discharged.
2. Set the meter on Ohm range (Set it at lease 1000Ohm = 1k).
3. Connect the Meter leads to the Capacitor terminals.
4. Digital meter will show some numbers for a second. Note the reading.
5. And then immediately it will return to the OL (Open Line). Every attempt of Step 2 will show the same result as was in step 4 and Step 5. It’s mean that Capacitor is in Good Condition.
6. If there is no Change, then Capacitor is dead.

 

Checking Capacitor By Multimeter in the capacitance Mode

Note: You can do this test with a multimeter if you have a Capacitance meter on your multimeter. Also, this method is good for tiny capacitors.

1. Make sure the capacitor is fully discharged.
2. Remove the capacitors from board or circuit.
3. Now Select “Capacitance” on your multimeter.
4. Now connect the capacitor terminal to the multimeter leads.
5. If the reading is near to the actual value of the capacitor (i.e. the printed value on the Capacitor container box).
6. Then the capacitor is in good condition. (Note that the reading may be less than the actual value of the capacitor (the printed value on the Capacitor container box).
7. If you read a significantly lower capacitance or none at all, then capacitor is dead and you should change it.

[honda_freak]

As Jonnyc21 already had shown here about to test a capacitor - wouldn't I repeat what he has written other than to say - that the capacitor is very vital part of the battery-less system and without the help of the capacitor during startup is it nearly impossible to start.

What I think you should check on your trial-bike has something to do with ECU voltage on terminal pin 5 on the ECU. Without five volt on this terminal 5 wouldn´t the ECU be able to activate the ignition and the fuelpump system properly.

 

 

Before you make this measurement be very carefull not to bend or break any terminals pins. You could make some extension leads to put in the ECU connector.

Remember when you make this mesaurement to put your DMM to record peak value as this voltage are not a steady reading or else you would get a false voltage reading.

Based on the result of that test - another test of the flywheel generator coil and recitifier / regulator may be necessary to conduct.

BTW is there a consistant blue spark between the sparkplug electrodes !!!
 

 

Regards

Honda_freak

Edited December 25, 2016 by honda_freak

[thall1]

Jonny/Honda freak....thanks very much for the info....once Santa is out the way I will have a look....

thanks very much

[thall1]

Just checked the capacitor using a digital multi meter with the meter test leads held onto the capacitor connector

pins...at first I was getting some resistance readings slowly increasing steadily to 1.9 on the 2K ohm range than a return to OL....but the initial reading upon connection was not a constant repeatable reading...

after trying to repeat the test again I was then just getting an OL reading....I then made some fly leads to connect onto the connector pins and again just got an OL reading. Assuming the capacitor was faulty I cut the plug off and bared the wires - both the leads are black with corrosion. After cleaning the leads I am now getting a constant repeatable reading of 17.65 MoHm with no return to OL....my guess is the capacitor has failed?....I cant read the capacitance as the identification has worn off....

[jfc]

Sounds like your capacitor was reacting correctly, but you need to use a capacitor tester or a multi meter that can read the capacitor. All you are doing by reading the resistance between the terminals is gradually charging the capacitor and the resistance reading will change until you get OL on the display.

Check your meter to see if you can set it to uf!

[thall1]

hi, my meter wont read uf...need to get a new capacitor any way as both the wires from the capacitor through the 2 pin connector and then back into the loom to within an inch or so of the next connection point are black with corrosion - about 30" of cable has now been replaced. I have removed both the male and female spade connectors from connection block and they too are heavily corroded where the cable is crimped on although the actual spade connection are quite clean. I have had these plugs apart on numerous occasions recently so I presume they have been scrapped clean when being disconnected/connected. I will get a new capacitor on order in the new year and go from there...hopefully this is the cause of the problems I have been having with starting the bike ever since I got it....you cant start it with the usual firm push on the kick start... it has always had to be kicked like a two stroke. On an earlier test the output from the 12v connection block under the tank was half that of a similar aged bike that's starts easily with a gentle push on the kick start....I have previously carried out a continuity check but not a resistant check on the all the earths and that was ok. I'll let you all know in the new year if this was the problem....fingers crossed it is!

[jonnyc21]

I am rooting for you!