1985 FJ73 Bogging down at 2000rpm

[FJ731985]

Hey guys, new to IH8MUD.

Racking my brain trying to figure this one out. Runs fine however when accelerating at around 2000rpm feels like bogging down/spitting/sputtering. I've changed all spark plugs, inspected leads, new fuel pump, just today did a carby rebuild. At each of these stages ive seen relief, but its been short-lived.

 

[ozcrusier]

Have you checked the fusible link ignition side could be getting hot and failing.

 

[FJ731985]

Have you checked the fusible link ignition side could be getting hot and failing.

Hey ozcruiser thanks for the quick reply. I will have a look thanks for the advice.

Forgot to mention that it only bogs down/spits for a few seconds then once past 2000rpm it accelerates fine. Once back under 2000rpm problem occurs once again.

 

[ozcrusier]

There's a electronic thing that sits on the carburetor does that click when you key on.

 

[roscoFJ73]

The 3F carb has a vacuum diapraghm on it. I forget exactly how it works, but at 1800-1900rpm mine use to do exactly what you described. If you paid someone to rebuild your carb, it is not usually included. But they should have noticed it.
Basically the diaphragm opens up the secondary stage but if it has leaks in it, it hesitates and you get the spluttering you experience. I forget how much they are, may be $50.

 

[FJ731985]

Hey Rosco thanks for the advice. Are you talking about the secondary vacuum actuator (3 minute mark)? A new diaphragm wasn't included in my rebuild kit however I did the test to see if it holds vacuum as the video above suggests and it does hold vacuum.

 

[FJ731985]

Hey ozcruiser, tested the fuel cut off solenoid today works fine.

 

[ozcrusier]

I haven't worked on a petrol landcruiser for years as I'm into diesel cruisers but does the carb squirt fuel down the throat when you twist the throttle.

 

[roscoFJ73]

Hey Rosco thanks for the advice. Are you talking about the secondary vacuum actuator

I forget, it was 13 years ago. I had the carb rebuilt but it still had the same symptoms as what you had. I took it back to the workshop that rebuilt it and I think they did say it was the secondary vac actuator.
If its not the actuator , it may be something attached to it.

Always seem to happen as you were turning a corner and changing gears and you would go to accelerate and it would run rough for few seconds, then it would be ok.
It is a fairly common problem with them.

I'm like ozcruiser, been away from carbs so long I forget how they work.

 

[FJ73Texas]

Good to know in case I have this problem with my 3F.

 

[roscoFJ73]

I was just wondering if the actuator is getting sufficient vacuum. Maybe a bad fitting or cracked hose?