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Worst Ride Ever - Bike Tried To Kill Me!

If you have a Gen 4, the easiest way to diagnose a problem, you have to unplug the guage and not disconnect the ground. The bike will not run at all if you disconnect the ground and leave the injector wires attatched. Unplugging the guage will take the function away from the o2 senser and and fuel modification, you will be operating only from the ECU. The guage will be off. This is easier than removing the injector wires for a test.
 
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harley@16 said:
If you have a Gen 4, the easiest way to diagnose a problem, you have to unplug the guage and not disconnect the ground. The bike will not run at all if you disconnect the ground. Unplugging the guage will take the function away from the o2 senser and and fuel modification, you will be operating only from the ECU. The guage will be off.
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Wow, good catch - thanks!
 
I don't know about the Gen4, but on earlier models, the TFI is more or less a hard-wire OR'd pulse extender. So, on those models, removing the ground does take the pulse extender circuitry off of the injector lines, but it will not fix an intermittent wire to an injector. The ECM signal is passed through (more or less), and the TFI holds the line for a bit after the ECM lets go of the line. An intermittent line will still be intermittent. Wiggle tests can be iffy as well, in that you may need to get the wires just so to get them to show as open/intermittent. I know. I struggled with this problem for months before I found it.

I have heard that the GEN4 can take away fuel as well as add, so the ECM signal must pass through active circuitry, on its way to the injector. If you remove the ground on this kind, the active circuit dies, and you will likely get no signal to the injectors.

Good luck,
Rich P
 
Dr. Dolittle said:
Hoople - So you think something was wrong with the fuel delivery system and the TFI AFR gauge was reflecting this by displaying full lean?
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No,, at this point the problem could be 1 of many things (ignition, fuel etc). Just saying that if you logged a P1353 &P1356, which are misfire codes, I would not be surprised to see a wide band indicate a false lean mixture.

No biggie,, I was just tying up the loose end for why the A/F meter may be indicating a false (and strong) lean condition
 
Not yet. Both daughters were home for the weekend. Youngest just went back to UGA a couple hours ago.

Family First!
 
harley@16 said:
If you have a Gen 4, the easiest way to diagnose a problem, you have to unplug the guage and not disconnect the ground. The bike will not run at all if you disconnect the ground and leave the injector wires attatched. Unplugging the guage will take the function away from the o2 senser and and fuel modification, you will be operating only from the ECU. The guage will be off. This is easier than removing the injector wires for a test.
Click to expand...

Well, I did this and the bike exhibited the same characteristics. So, I guess that removes the TFI as the culprit.

Battery passes a load test.

No check engine light, but 1353 code is back. Not the other one but I only rode it about 5 minutes.
 
Dr. Dolittle said:
Well, I did this and the bike exhibited the same characteristics. So, I guess that removes the TFI as the culprit.

Battery passes a load test.

No check engine light, but 1353 code is back. Not the other one but I only rode it about 5 minutes.
Click to expand...

Dr.

Just asking;

Did you plug the gen4 gauge Back-in and try it again that way?

Remember steve07 made it home running really lean from a line leak in the tank... Used the ge4 to richen the fuel mix...

Be interesting to see IF you can UN-Lean it with the gauge settings. (not a fix but a test)

signed....BUBBIE
 
Just a thought check your fuel level and try filling the tank. The plastic hoses on the fuel pump develop small leaks causing low fuel pressure. A full tank often causes enough pressure to stop the leak and restore fuel pressure. Also run a fuel pressure test and make sure you are getting enough pressure. I have seen this issue several times, the alcohol in our gas causes quit a few problems.
 
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