Well, I bought her used with only 18000 on the ticker, so I don't know if the wires were ever changed...I would think not. I know the plugs have been changed since I usually put a new set in before the riding season really starts...cheap insurance. Thanks to everyone for the inputs as this gives me some good areas to start my "CSI" investigations to start with. Looks like I will be pretty busy once I get home tonight!!!!:newsmile04:
My back cylinder just quit working!!!
- Thread starter JKJunkie
- Start date
BUBBIE
Well-Known Member
Yep that is what I meant... Thanks Hoople.
Also The wires are Not expensive so I would replace them with Not knowing how long on the bike....
signed....BUBBIE
Start with the simple stuff. Is the spark plug wire loose? If not, wiggle the injector plug wire as you try cranking it and see if it intermittently tries to run both cylinders.
If it was the first problem - fixed!! But I agree with the comments above that you should replace them.
If it is the second problem, not so good. You are gonna have to repair those wires/plug connector.
If not those two, pull the plug and see what it looks like. If badly fouled, take a pix and let us see.
If none of these, check for codes and let us know.
TQ
wannaride
Active Member
Mine is doing the same thing, it's a 1999 Ultra. But at first it was flooding the cyls (both). After I replaced the crank sensor, it no longer is flooding the cyls, but is not running on the rear cyl. Before the crank sensor it would start & then die with in a minute & not restart until I dried out the plugs & cylinders. After the crank sensor it starts & dies unless you throttle it up a little. By adding fuel to the rear section of the throttle body, it smooths right out & will idle as long as you keep adding fuel. When I get a chance to get back out & check it out I am going to listen to the injector on the rear & see if it clicks while it is running. I am contemplating replacement of the cam sensor just because of it's age & 83000 miles. Good luck on yours & keep us posted.
Toby
I started it up this morning & while giving it throttle to keep it running I used a listening stick to hear the injectors clicking, they both are. That leaves the fuel pressure that I need to check. Being a 1999 it looks like I need an adapter that has a 1/8 " pipe plug thread, once I get or build an adapter I will find out if that is it. With the pipe plug out & the key on, there was plenty of flow, but if the pressure is too low, it may be enough to do one injector but not enough for the other. How are you doing JK?
Toby
Toby
I started it up this morning & while giving it throttle to keep it running I used a listening stick to hear the injectors clicking, they both are. That leaves the fuel pressure that I need to check. Being a 1999 it looks like I need an adapter that has a 1/8 " pipe plug thread, once I get or build an adapter I will find out if that is it. With the pipe plug out & the key on, there was plenty of flow, but if the pressure is too low, it may be enough to do one injector but not enough for the other. How are you doing JK?
Toby
Last edited by a moderator:
Just thinking out loud...not sure if the front and rear injectors are the same part number, but if they are you could swap them, it would eliminate bad injector...AFTER you inspect the all the wiring to and from them. May have corrosion or bad connection causing intermittant operation. Fuel injectors work based on the signal/duty cycle of the pulses to "spritz" appropriate amount of fuel into the cylinders. I usually go with no/low cost troubleshooting, disturbing things as little as possible, using good inspection techniques and a DMM to be sure.:s
wannaride
Active Member
Getting to the injectors is not easy. Getting them unplugged without pulling the tank is also hard. That is why I used the listening stick to see if mine were getting a signal. The injectors are about a year old & I still have the other injectors (1 with the word bad on) that I could trade with the one that is not working but I think I need to know what the fuel pressure is first. If that checks out ok, then the next step would be to pull the tank & swap the injectors to see if the dead cyl moves with it. As it is, if the pump pressure is low, that does not mean the pump is faulty. It could be a hose in the tank even though they looked ok when I replaced the filter. But I did not pull it all out & inspect, just looked at the hose that I could get pulled out of the tank. Thanks for the input on my problem as well as JK's.
Toby
Toby
Well, I took mine in to my mechanic and he is thinking that the wire to the injector is broken inside the insulation. He said he's seen it quite a few times before. I am also having him check the cam chain tensioners and put new tires and brakes on her. Thanks for all the input. I ended up having to put a couple lift kits on some Jeeps and didn't have time to really get into my own project. Thanks again!
wannaride
Active Member
Did a test, 43psi, didn't change when started & reved up . I did dead head the fuel pump & it shot right up to 90. Did it while it was running & made no difference the way it ran. Pressure did not drop while sitting there with the key off. So no problems with the fuel pump or the lines inside the tank. Next step is to pull the tank to get to the wiring & possibly pull the injectors if the wiring is ok.
Toby
Toby
wannaride
Active Member
Got my noid light on the injector connector, flashing away like it is supposed to do. So the wiring should be ok. Went ahead & pulled the intake all the way out, I need to change the throttle cables out since they are fraying the plastic since I did the inner fairing. Also because & don't have a good set of snap ring pliers here at the house. Just put those injectors in this last year, good thing I still have the old ones & wrote bad on the bad one. I may send them in to get checked just because they are out & it would be a lot easier than putting them back in just to find out that the other one went bad sitting on my tool box at work. Maybe when I get the injectors out it will have a plugged screen (hope). We have had some great weather & wish it was running.
Toby
Toby
Hoople
Account Removed
I don't have a service manual for a 1999 but isn't 43 psi low? My guess would be closer to 60 PSI. I can dig out the correct spec but what does your manual say it should be. Sounds low to me.