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New 124" build: no response from injectors

Yves,
Let us know what happens.:)
Scott

Hey Scott!!!
I will, I have 2 sheets of things I need to check this weekend.
It's a good thing I have the electrical diagnostic manual, but to tell you the truth, that's one manual I hoped I'd never, ever need!
 
I'll unplug the twist grip sensor, I know for a fact (because I did it last year) that the bike will start without it (it goes in a fast idle/limp mode and throws a DTC).
First thing I'll do is re-install the stock TB and stock ECM calibration, and move from there.

I possibly would reverse a couple of your steps but if you have a plan, go for it. Even though you experienced seeing the bike start without the twist grip cable plugged in, I would not count on that being an error you can duplicate at will. Maybe yes, maybe no. It makes no sense to me that the bike would even start with the "summing +5 volts" missing. Yes, I believe you when you say it happened, but looking at it software wise it makes no sense at all. It really indicates to me that there may be a loose screw in the error detection program but who knows. Think about it,, It's one thing if the bike was already running, the cable happen to break and the engine kept running at idle speed. It's another thing if the cable was cut and the bike would still be allowed to start. To me, that would be lunacy. These types of decisions are part of a written program. Written by who is what scares me.:p

I would verify the twist grip pots first, get the summing voltage present and corrected. That must be corrected regardless if it fixes the injectors or not. If it does fix the injectors, then you don't need to swap throttle bodies. If it doesn't fix the injector problem, just proceed.

Either way I am curious to see what you find. You do have an interesting problem.
 
I possibly would reverse a couple of your steps but if you have a plan, go for it. Even though you experienced seeing the bike start without the twist grip cable plugged in, I would not count on that being an error you can duplicate at will. Maybe yes, maybe no. It makes no sense to me that the bike would even start with the "summing +5 volts" missing. Yes, I believe you when you say it happened, but looking at it software wise it makes no sense at all. It really indicates to me that there may be a loose screw in the error detection program but who knows. Think about it,, It's one thing if the bike was already running, the cable happen to break and the engine kept running at idle speed. It's another thing if the cable was cut and the bike would still be allowed to start. To me, that would be lunacy. These types of decisions are part of a written program. Written by who is what scares me.:p

I would verify the twist grip pots first, get the summing voltage present and corrected. That must be corrected regardless if it fixes the injectors or not. If it does fix the injectors, then you don't need to swap throttle bodies. If it doesn't fix the injector problem, just proceed.

Either way I am curious to see what you find. You do have an interesting problem.

If I remember well, it's called the "limp home mode", the idle is a fast idle allowing just enough power to crawl back home.
I just did a bunch of testing, here is what I found out.

Resistance across the terminals of all 4 injectors (2 stock, 2 SE 5.3gps) is 14.3 ohms (normal = 10 - 25 ohms).

Voltage at + side of injector connectors and battery ground = 12.7V

Voltage at + and - side of injector connectors (injectors out) with cranking = 10.45V (rear) and 10.50V (front).

Continuity front injector ground Y/W to ECM plug 28 = 0 ohms

Continuity rear injector ground GN/GY to ECM plug 23 = 0 ohms

ECM ground plug 73 to ground in frame = 0 ohms

I logged data of the twist grip sensor, ignition on, not cranking = 6.4% not changing while twisting the throttle (not sure if this is normal while not cranking engine).

I logged startup, one injector plugged in at a time, on the first attempt at cranking the engine over (plugs out) I got a BPW of 55.30ms on each injector, but it stayed at 0 on subsequent attempts (this is my first sign of injector activity since last Saturday). It's as if the injectors were inhibited on the subsequent attempts.

Fuel pressure upon priming is 58psi.

12.73V at fuel pump power connector.

I re-entered the stock ECM calibration, I'm in the process of re-installing the stock TB, then I'll try a startup again.
 
Great Data.... This is interesting.

Your sitting on the problem. I don't have drive by wire but I would say you should have seen rotational feedback on the laptop when you twisted the hand grip. If it is not suppose to show you laptop feedback, what good is it and I want to know who is writing these firmware programs!!

The betting Windows will be closing in 5 Minutes. Place Your bets before it's too late!:p:p

Twist Grip to WIN for $10
Throttle Body to PLACE for $10
Another $10 bucks on Grip to SHOW!
 
Great Data.... This is interesting.

Your sitting on the problem. I don't have drive by wire but I would say you should have seen rotational feedback on the laptop when you twisted the hand grip. If it is not suppose to show you laptop feedback, what good is it and I want to know who is writing these firmware programs!!

The betting Windows will be closing in 5 Minutes. Place Your bets before it's too late!:p:p

Twist Grip to WIN for $10
Throttle Body to PLACE for $10
Another $10 bucks on Grip to SHOW!

I was thinking maybe that rotational feedback only show up when the bike is running, like I said, on my 107" build, the TPS was disconnected and the bike fired up on the first attempt.
Well everything stock is back in, the moment of truth.
I'm probably going to have a bit of intake leak, the stock TB is not exactly designed to fit between the 2 taller Axtell cylinders, the flange is well against the head though.
Wish me luck!!!

OK so here it is.

I tried to start the bike, NOTHING!!!

I unplugged the twist grip sensor, it fired up on the 2nd attempt and does run (a little rough considering I have a tune, TB, and injectors for a 96" engine trying to feed a 124" one)!

How do you test the twist grip sensor exactly???

Thanks
 
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Sally Twist Grip comes in by 6 lengths!....
It's a Good thing because it was the last $30 I had !!

Go to enty point #32 of this thread. Take that link to the next thread. That PDF has everything you need.

You got it solved and the weekend just started... Nice troubleshooting...!.
 
Sally Twist Grip comes in by 6 lengths!....
It's a Good thing because it was the last $30 I had !!

Go to enty point #32 of this thread. Take that link to the next thread. That PDF has everything you need.

You got it solved and the weekend just started... Nice troubleshooting...!.

I ended up doing a lot of testing for nothing, and the same thing probably would have worked with the 58mm TB, 5.3gps injectors, and TTS tune but there was no way I could have known, there was NO DTC whatsoever!
I hope the problem is just that I didn't do the connections right when I changed the plug. Take a look at my handlebars, I'd rather poke needles in my eyes then go through the task of getting the TPS wire through there again!!!
flhx124584.jpg
 
It's never for "nothing". If it had been a simple easy fix, it would have just been another task to perform and you would not have learned anything. "No DTC whatsoever!" you say. Next time that won't surprise you. Computers have to be told what to do even when the decision seems obvious. Code writers are just people working with budgets and dead lines and I bet some of them don't even ride. :p

And Hey, Nice Scooter!
 
It's never for "nothing". If it had been a simple easy fix, it would have just been another task to perform and you would not have learned anything. "No DTC whatsoever!" you say. Next time that won't surprise you. Computers have to be told what to do even when the decision seems obvious. Code writers are just people working with budgets and dead lines and I bet some of them don't even ride. :p

And Hey, Nice Scooter!

You're right about the "nothing" part. I pretty much learned the wiring diagram by heart and now have a better understanding of the HD EFI system than I ever thought I would. If I have other problems, I now know the testing procedures for a lot of parts/sensors so I guess it was a learning experience.
Now I have to figure out that TPS. I printed the document you referred me to, I'll see if the electrical diagnostics manual has a wiring diagram of the one piece TPS (the one without the green connection in the middle) to see if I can make it work with my stock input plug.

Thanks again for all your assistance.
 
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