Bucking 87 FJ60 (1 Viewer)

[krzyabncanuck]

I need some help. I have an 87 FJ60 that has a Jimc rebuilt carb from about a year ago, new fuel pump(oem) same time, and just changed out fuel filter. At idle it is fine , about 1200-1800rpm it will hesitate for a second or two then return to normal, above 2000 rpm it will act like it only has 3/4 power but no hesitation at all. It will not do this all the time , it did it going to gym this morning and all day yesterday, but by the time i got back home (25 mile one way country driving ) it would not do it . Going down the road it will buck every once in awhile. It has been doing this about one week now, but not all the time. Only when it wants to it seems. I was thinking maybe trash in the bowl or a clogged jet. Watching the site glass the fuel never gets below 1/2 way down so I would guess it is not the pump. Or maybe just bad gas could do this. Any help would be greatly appreciatted.

 

[CATMECH]

Have you checked your distributer cap and rotor? It almost sounds like a ignition problem. I would pull off the cap and rotor check for cracks or carbon tracks on the inside.

 

[BlueCruiser84]

Check your EGR valve. I had the exact same problem and that is what it was. Just pull out the hoses that go into it and plug them with screws.

I don't think this would be the cause since you just had it rebuilt, but you could also check the primary jet in the carburetor. Mine was all messed up so it wasn't delivering fuel fast enough.

Brian

 

[BlueCruiser84]

and when i say you had "it " rebuilt i mean the carburetor. Sorry i forgot to specify.

 

[krzyabncanuck]

Alright, 1st, thanks for the responses. Now a little update, checked cap and rotor, they were still good, plugged egr and no change. Now the next question that might be the culpret, how full should the fuel filter be when idling, mine is has about 1/4 to 1/2 inch of fuel in it while idling.

Thanks again.

 

[humper99]

Fuel filter should be full at any rpm. The only time my fuel filter has any air in it is right after I've changed it and then it is still 90% full with a few air bubbles that need to be worked out.

 

[dogboy2]

so many overlapping conditions can cause this symptom: you've already started down the road of elimination by system, so another good place to look is the vacuum system -- check all of your lines for cracks/poor condition and correct routing.

our '60 suffered from a similar condition. solution?: 1) full tune-up 2) new fuel pump & filter 3) corrected vacuum line routing 4) new EGR valve 5) new BVSV's. this solved the bulk of the problem, especially once the EGR and BVSV's were replaced and it solidly passed emissions where it struggled to do so before. now it runs pretty damn smooth, but will be replacing all of the vacuum lines with new and then will have the carb rebuilt again, this time by Jim C (shop that did it the first time did a hack job of it)

hth,
-dogboy- '87 FJ60

 

[krzyabncanuck]

Dogboy2 , can you see what level your fuel filter is at when running, and because it is before the pump would that be the pump or maybe a clog in the line or tank ?


Thanks

 

[dogboy2]

it runs full -- just below the top of the filter, where the in & out lines go.

-dogboy- '87 FJ60

 

[krzyabncanuck]

Thanks, mine is still running about 1/4 full, am going to get another one and see if this new one might be the culprit.