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1994 FZJ 80, carburated with hesitation

Posted: Sat Feb 06, 2010 2:48 am
by CRFZJ80
Hi,

First post for me, so greetings from Costa Rica.

I have a 1994 FZJ80 with the basic package (seats 9 with rear inner facing seats, 5 speed, gas (petrol) 4.5 engine, vinyl floor mats and seats, manual windows/locks.)

I was hoping someone might be able to help me diagnose my hesitation during acceleration. The carb has a flat spot upon accelerating when I push the accelerator pedal more than halfway down. It bogs and stumbles at that one spot. I can push past it sometimes, by giving it more gas, but not usually. This happens until the engine is warmed. The carb has an electric choke.

I was thinking ia possible cause might be the gasket which sits between the carb and the air cleaner intake. Maybe it has a crack and air is getting sucked into the car through the crack? Or maybe it is my squashed exhaust which was caused by the previous owner not fixing the hangers and letting the pipe bang on the rear crossmember near the axle.

Any thoughts are welcome.

Thanks in advance.

Jason

Posted: Sat Feb 06, 2010 10:12 am
by GO79
Not to sure jason
But Australia never got the carby version 1fz-f we only get the 1fz-fe ijnected
so you might not get much info help

Posted: Sat Feb 06, 2010 10:45 am
by lucifer48
Never seen a carby version myself, but i will have a guess at it.

First thing is to check the timing and make sure it is advancing.

Check to see if the pump plunger (might be a diaphram) is is working correctly- pumping fuel down the throat of the carby as soon as you press the throttle. If not that would be your problem.

And also on a lot of Aisan carbys the earth wire on the idle solenoid goes through a vacuum switch, this switch almost always goes faulty and this will give a flat spot at around 1500/1800rpm.
The way to fix it is by using a test lamp to determine which wire is the earth wire coming OUT of the idle solenoid, then cutting that wire and taking straight to earth- normally just on one of the bowl screws of the carby.

Post a pic of the carby if you can.

Re: 1994 FZJ 80, carburated with hesitation

Posted: Sat Feb 06, 2010 3:00 pm
by udm
CRFZJ80 wrote:Or maybe it is my squashed exhaust which was caused by the previous owner not fixing the hangers and letting the pipe bang on the rear crossmember near the axle.
that is a factory made squash.

Posted: Sat Feb 06, 2010 3:02 pm
by udm
You got any motor and interior pictures of your car? Ive never seen one, actually, dont think any of us have.

Posted: Sat Feb 06, 2010 4:29 pm
by beinthemud
It doesn't realy cause a bad bog down but more of a stutter, does it run a prejet. I Had a RX7 That some idget blocked it off and it kinda did that might help