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Suddenly will not revv


griswoia

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6 hours ago, griswoia said:

Love all the advice.  I just put in a new fuel filter 6 weeks back.  No reason than I was insulating the pump and figured 20 years on the same filter was enough.

I'm going to check TPS in the next day or so.  Looks like there is one on the right hand throttle body.  I'll report back.  Not sure where the crank angle sensor is have to look that up.

Now you tell us LOL. Don't forget the fuel tank pick up filter screen.

Ciao

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If it will start , I would say the crank angle sensor is ok . I am going to say to test TPS sensor . If you don't know how , just acknowledge it & we will help you .

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Ok so UPDATE.  Just cranked it and idles like always.  Unplugged the TPS.  Idel did not change (big surprise right) but revving is almost exactly the same.  Things is guys it was warming up so the roll on changes anyway.

 

Point is TPS plugged it won't revvs coughs and backfires/does.  TPS unplugged and see behaviour.....  So I'll look at more TPS checks but looks like that's it.

 

Thoughts?

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1 hour ago, griswoia said:

Ok so UPDATE.  Just cranked it and idles like always.  Unplugged the TPS.  Idel did not change (big surprise right) but revving is almost exactly the same.  Things is guys it was warming up so the roll on changes anyway.

 

Point is TPS plugged it won't revvs coughs and backfires/does.  TPS unplugged and see behaviour.....  So I'll look at more TPS checks but looks like that's it.

 

Thoughts?

Unplugging the TPS and trying to rev the engine is a pointless test. Of course it will not rev and cough etc the same as not getting enough fuel because that's exactly whats happening.

To test the TPS you need to use an Ohmmeter on it and look at the resistance shift verses the positional rotation.  

Ciao 

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When I did a little fuel system maintenance, I found brown fuzz in the fuel tank shutoff screen, in the fuel pump inlet screen, in the injector inlets, and in the regulator screen. The fuzz on the tank screen was so thick that it looked like felt wrapped around the screen. The fuzz probably came from a decomposing fuel filter paper element which was exposed to too much alcohol or injector cleaner. I imagine that if it got thick enough it would restrict engine power, but not necessarily rpm.

I cleaned all the fuzz I could find, washed out the tank with hot water and detergent, renewed all the fuel hoses and the fuel filter, back flushed the injectors, and after all that it ran just as well as before.

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Simple things to check:

1. Make sure the hose on the new fuel filter isn't loose. If it's an external filter, it'll be easy enough to check. Might as well make sure the flow is the proper way as well. I'm sure you did it right the first time, but it doesn't hurt to double check.

2. Make sure nothing crawled inside your exhaust pipes or intake.

3. Did you fill up with gas right before this happened? 

4. Make sure the throttle linkage moves freely with the throttle. 

5. Check the fuel overflow hoses that connect to the underside of the tank. I don't know what happens if these aren't connected

6. Check the coil connections if you took the tank off. Hopefully you didn't bump a wire loose.

If you have guzzidiag, you can test the FI and the TPS with it, as well as check for faults. That would save some time vs. testing everything manually with a multi meter.

Hope this helps,

Ken

 

p.s. crank sensor is on the left side of the bike towards the front of the engine. 2 bolts hold it in, and it's oval shaped. I don't remember where the connector is, but you may have to lift up the tank a bit or remove it. I replaced one last year on a EV side car rig with Chris Collins, and I think it was somewhere under the ignition or behind the headlight on that bike.

Ken

cs.jpg

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OK hooked the bike up to guzzidaig and the TPS is reporting angle just fine.  So now how do I check the crank angle sensor?

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On 7/9/2019 at 1:01 PM, Paradiso said:

Maybe check the throttle cable on the left hand side. It can come off the (semi ) circular cam.

Sent from my SM-G925F using Tapatalk
 

This is a good idea...

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All connections around the throttle bodies look good.  Checked the coils for corrosion at connections, nope.  Plugs are <2Kmi and tan.

 

Going to read the advance on guzzidiag as this should be calculated off crank angle sensor.  If I have doubts I might swap with my running bike.

 

All else checks out I am really thinking this is fuel pressure......  So that would be off with the tank.

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Like mentioned here before, its very easy to Ohm the rev sensor, should be around 650 - 700.

Cheers tom.

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unhooked powercomander 3 usb and IT WORKS!

 

GDIA!!!

 

OK Open pipes, pods, crossover.... what map should I run?

 

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reconnected PC3USB and runs fine...... so bad connection.

got this as the PC3 kept flickering as it passed over 1500rpm.

thanks for the help folks.

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37 minutes ago, griswoia said:

reconnected PC3USB and runs fine...... so bad connection.

got this as the PC3 kept flickering as it passed over 1500rpm.

thanks for the help folks.

So you didnt think it was sort of important that you would mention the bike is fitted with a power commander?????????

It takes you half the thread to mention you recently replaced the fuel filter!!!!!

Seriously, people come on here for troubleshooting advice and help and leave out the basic but highly relevant information.

This is why I'm reluctant to get involved too much in these troubleshooting issues and waste my valuable time.

Ciao  

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