stumbles, stalls, wouldn't re-start

[dougrs]

On my way to work my '89 died and wouldn't re-start. She had been running pretty well. I cleaned the carbs, replaced the fuel pump, new starter, and did some other stuff a couple months ago and the bike had been running fairly well I have been riding a couple times a week. Once before I believe I got a piece of crud that caused the float needle to to seat right and it leaked some fuel after i parked it. then one other time when the engine was not warmed up it chugged a little, the idle dropped and a red light, and it died. It would not restart at first, but after a few minutes of trying it did start and ran just fine. I have been riding since then and it has been running fine. Usually starts right up with a little choke, then I can quickly turn the choke off and it runs well.

Today it started up fine and i started off and it seemed fine, but quickly it start running a little rough, but not terrible. this progressed to getting even rougher and it was really lugging. I pulled the the choke out and that kept it idling around 3k but as soon as i tried to go in 1st gear it really struggled. At this point I turned around hoping to struggle home. It got worse and died a couple times when I tried to get moving at red lights. It would not start easy but did restart a couple times. finally when I was very close to home it died and would not restart and it was acting like the battery was low. This is likely from all the cranking I was doing trying to get it restarted before. So it is parked in a lot near my home.

I understand that this could all be related to the fuel system but I think some folks have had issues with their ignition system too right? I will try to get it to start and limp home after work.

[andyb]

Fuel filter springs to mind as not being on the list of stuff done recently.  Possibly venting on the gas tank as well.  And the old favorite, a kinked fuel line.


Electrical is possible, but you'd think it wouldn't want to restart at all, or would have a gross misfire rather than a progressive weakening.  There'd be a strong fuel smell from the exhaust when cranking it on choke when it wasn't starting, also.

[dougrs]

I got the bike home. It started right up this afternoon. It idled fine with a little choke initially then I took off and within a couple hundred feet it was struggling again but it kept running, i got it into second and it was no better, very rough, then it started running worse and died as i pulled in. after a few minutes it started again just fine and would idle, but bogged when i twisted the throttle.

So at this point I think the my tank was not as clean as it should have been and some of the gunk in there clogged up my carbs. The fuel lines, pump, and filter are all new and the carbs were cleaned.  so i will be cleaning the tank and cleaning the carbs.

[dougrs]

Fuel filter springs to mind as not being on the list of stuff done recently.  Possibly venting on the gas tank as well.  And the old favorite, a kinked fuel line.


Electrical is possible, but you'd think it wouldn't want to restart at all, or would have a gross misfire rather than a progressive weakening.  There'd be a strong fuel smell from the exhaust when cranking it on choke when it wasn't starting, also.

I'll check for a kink in the fuel line, I hope it is that simple, but i have a feeling it is not and I need to clean the carbs again. After riding it this afternoon, I don't think it is electrical.

[Arnie]

Don't forget to check and clean those little screens on top of the float valve jets.

Arnie

[fj1289]

Couple thoughts - try filling the fuel tank to see if you have some kind of a feed issue at lower fuel levels. Try temporarily bypassing the fuel pump to see if the pump is an issue when it gets hot. The pump operates off a set of points -- they may be sticking when the pump gets hot? 

[dougrs]

Couple thoughts - try filling the fuel tank to see if you have some kind of a feed issue at lower fuel levels. Try temporarily bypassing the fuel pump to see if the pump is an issue when it gets hot. The pump operates off a set of points -- they may be sticking when the pump gets hot? 

the tank is full, filled it on the last ride. and the pump was replaced recently with the airtex pump.

[dougrs]

Don't forget to check and clean those little screens on top of the float valve jets.

Arnie

yup I will. the carbs were clean and it ran well for about 600 miles, but I think the junk in the tank finally made its way to the carbs. the tank wasn't bad, but i think there was some remaining gunk in there.

[dougrs]

I figured I would follow up on my old post from earlier this summer. I have been reading lots of old posts on the forum in order to get my bike dialed in. I was able to figure out the she was still running lean based on the large numbers of posts on that issue. I richened her up a bit and dropped the idle down to 1100rpm and she is really running great now. I want to re-sync my carbs but I'll get to that later. thanks!

[movenon]

I figured I would follow up on my old post from earlier this summer. I have been reading lots of old posts on the forum in order to get my bike dialed in. I was able to figure out the she was still running lean based on the large numbers of posts on that issue. I richened her up a bit and dropped the idle down to 1100rpm and she is really running great now. I want to re-sync my carbs but I'll get to that later. thanks!

Thanks for the follow up. So many times we never find out what happened in the end. When you richened it up did you change jets or just adjust the fuel / air screws ? Yes, the FJ's seem to like that 1150 - 1100 rpm idle (factory spec). Syncing the carbs will probably help also. Not hard to do and can be done with low tech equipment. My sync tool cost me about 15.00 to make.
George

[dougrs]

I adjusted the screws to richen her up. It ran fine, but then it sat for a couple years, so this spring I began the process of getting it back in running condition. I synced the carbs already after I cleaned the carbs so I have the tool and plan on doing it again at some point.

[movenon]

FJ's are just like F-4 Phantoms, if you just have to keep thrashing them they will run fine, let them sit and you get all kinds of unhappy gremlins... 
George

[NJona86FJ]

Just as pretty as an F-4 too .... love bricks with wings....

[movenon]

Just as pretty as an F-4 too .... love bricks with wings....

In deed  Just need to put a vari ramp in front of the FJ scoops.... Kinda hard to crawl the intakes....
George