1995 1FZ-F ....Slight Bucking and Hesitation At Low Throttle (1 Viewer)

[ASO544]

Just getting some miles on this new to me Series 70 JKZ73 and I have noticed I have a low throttle bucking and somewhat hesitant jumpy throttle response when initially taking off. The vehicle starts up fine and idles fine. I have to use a lot of clutch and throttle to get it rolling good when taking off, and then when I shift into 2nd, I have to do the same thing with the clutch and throttle. After driving it for 15-20 minutes it’s starts to get a little better but never perfect. Once it’s at cruising rpm it runs fine. It also hesitate initially if you floor the gas but then cleans up and takes off.

This vehicle came for Bogota which is at 9K above see level and the carb hasn’t been adjusted now that’s it’s a sea level here in Florida. Think that might be my starting point ?

From the looks of the engine, the fuel filter, dizzy, wires, ( possibly plugs) and fuel pump seem to be reasonably new. I leaning toward maybe needing a slight carb adjustment.

 

[ceylonfj40nut]

Most of the 1fz’s here on Mud are fuel injected. Might want to speak to a carb specialist in the 40 or 60 section. Altitude adjustment does not usually cause the symptoms you describe. Could be a sticky butterfly valve or clogged secondary valve.

bogging down is usually also a sign of vacuum leaks. Spray some carb cleaner at the base of the carb, intake manifold are and see if rpms go up. If it does, you may have a vacuum leak. May explain why it runs better when hot.

 

[roscoFJ73]

If its a 1FZ 6 cyl, the vehicle is a FZJ73. It is on the aluminium plaque on the firewall. Its important to know when ordering parts etc.
Sounds like it needs a carb rebuild.
The KZJ73 is a 4cyl diesel with coil suspension.
Its looks nice and clean, do you know the year?

 

[ASO544]

I missed typed the model. It’s an 1995 FZJ73

 

[OGBeno]

It’s most definitely time for a carb rebuild.

 

[roscoFJ73]

Do all 7* series come with the heat insulation under the bonnet? I heard the heat eventually causes the paint to discolour.

 

[OGBeno]

Do all 7* series come with the heat insulation under the bonnet? I heard the heat eventually causes the paint to discolour.

No. Many do not. But all can be a retrofitted with one. All the holes are there. At least with all narrow front set-ups.

 

[roscoFJ73]

Ive seen a lot of nice 70/73/74 with no insulation but my 73 had it and so did my 2 75 series. Maybe the Toyota Australia deemed it necessary for all their 7*