News:

         
Welcome to FJowners.com


It is the members who make this best place for FJ related content on the internet.

Main Menu

Running Rough

Started by drivingbored, April 13, 2022, 08:01:18 PM

Previous topic - Next topic

drivingbored

Hey y'all I got my carbs rebuilt by RPM and installed them on my 1993 FJ1200. However, the bike is running really rough. It wants to idle at about 2k rpm and bounces around in the range. When I apply throttle it dies. What could be causing this? and where should I start?

T Legg

Check if you  have a sticking choke cable . A partially engaged choke could have those symptoms.
T Legg

Pat Conlon

Yep, good call Travis....a hanging choke cable...
The op could have multiple things happening....A high idle could also mean a vacuum leak.
Check your intake manifold o rings and vacuum line to the ignition advance module.

Engine dying, sounds like a fuel issue...
Check the reserve rocker switch to see it's in the correct position....got enough fuel?
The engine dying could also mean a bad fuel pump.
Try bypassing the fuel pump, run the carbs on gravity see it that helps.
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

drivingbored

Okay so I have checked the choke cable and it's fine. I have about 4 gallons of fuel in the tank along with some seafoam and the rocker switch is on ON. I did see a kink in my fuel line that would not go away so I replaced that and it seems that has helped. But now when I start it, it instantly wants to go up to 9k rpm and stay there and may start to climb. So I am thinking there is an airleak. Any other suggestions? This bike was working fine last summer :(

RPM - Robert

Did you unhook the throttle cables and confirm they are not hanging? Give us a shout and we will get you fixed up.

drivingbored

I have checked the cables and they seem fine. They come to a complete rest when no throttle is applied. I'll give a holler to yall.

Pat Conlon

Quote from: Pat Conlon on April 13, 2022, 09:43:08 PM
A high idle could also mean a vacuum leak.
Check your intake manifold o rings

The engine dying could also mean a bad fuel pump.
Try bypassing the fuel pump, run the carbs on gravity see it that helps.


Fresh manifold o rings?  
Is your fuel pump working? How do you know?
Try bypassing to see if it helps. It's easily reversible.
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

drivingbored

Okay, so I got it to run right and idle correctly. Replaced the carb boots and adjusted the idle screw. Drove it about 3 miles to the gas station and put 2 gallons in it. Did a pull and it was fine. On my ride back it started to sputter and then die :Facepalm: Was able to walk it back to the hanger.
It will barely idle then it will die. And it kind of sounds like a misfire. The fuel pump is pumping fuel I can take off one end of the hose and have it feed fuel into a bottle. I can blow the fuel line to the petcock and I can hear bubbles in the tank so I don't think the petcock is blocked. I can blow the other end and push fuel through the carb. I tested spark plugs and they are fine.
I think I will try to bypass the fuel pump soon. What do y'all recommend to use? Water bottle?

Pat Conlon

Connect together the fuel line on the pump inlet with the line on the pump outlet.
https://www.homedepot.com/p/Freeman-3-8-in-x-3-8-in-Male-to-Male-Barbed-Coupler-Z3838MMBC/203518338
Keep your tank at least 1/2 full and go for a ride.

I think your fuel pump is failing....
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

drivingbored

Thanks, pat will try.

gdfj12

If it is the fuel pump, Allballsracing.com has a rebuild kit for it.


George D
George D
'89 FJ1250 ~'90-black/blue
'87 FJ1250 ~streetfighter project
'89 FJ1200 ~white/silver, resto project
'88 Honda Hawk GT, resto project