New Member FJ-70 / Carb. Problem

[Khorrassany]

Hey Everyone,

I'm a new member on this forum I live in Cairo/Egypt and have a 1989 FJ-70. The car has 375,000 KM on the clock and I bought a new carb and installed it 2 weeks ago, but the car hasn't been running well like before it hitches when I push on the gas then it runs fine. I checked all electricity and fuel system. And everything fine...so any suggestions ?

Thanks in advance
Issa Khorrassany

 

[roscoFJ73]

Is it the standard carb? Maybe someone can help but they need more info about what it was doing before you replaced it,is the fuel pump new ect.
At what rpm does it happen?

 

[Khorrassany]

Hi Rosco,

Yes, it's the standard carb. I bought a new one but it's for the 90's model, exactly the same like the old one with extra vaccum hoses. I replaced the old one cause I had some problems with the plates axe "throttle shaft". I rebuilt it a year ago and decide to buy a new one better. It does it on low rpm ~2000 rpm.

sorry for the bad english , i'm not so good in car terminlogies !
Issa

 

[wesintl]

You might try the 60 series section too. The forum is becoming more international but there are not many folks with a gas FJ70 save maybe some folks from venezuela where as most of the folks in the 60 section have carbs and a more similar engine. Speaking of which, do you have a carb'd 3f?

Did you plug the extra vacuum connections?

 

[roscoFJ73]

Hi Rosco,

Yes, it's the standard carb. I bought a new one but it's for the 90's model, exactly the same like the old one with extra vaccum hoses. I replaced the old one cause I had some problems with the plates axe "throttle shaft". I rebuilt it a year ago and decide to buy a new one better. It does it on low rpm ~2000 rpm.

sorry for the bad english , i'm not so good in car terminlogies !
Issa

Mine used to run bad around 1800 and it was the bit on the side that activates the secondary stage,the name of the part esapes mepic below.
A fairly common problem on these carbs.Most of those hoses on mine were for the aircon
Is the engine a 3F? Im surprised you can still buy carbs for these. The supply dried up in Australia a long time ago.

 

[Khorrassany]

Yes, it's a carbd 3F engine....I had to wait a while for the carburetor and I got it finally from Libya ! There is a lot of 70's series here in Egypt..a lot of them are owned by travel agencies.
My mechanic worked on replacing the carb and he plugged the vaccum hoses, but if there is any pics or manual so I can recheck what he did, would be perfect.
Rosco how can I know if this part is working fine or not ?? I think I will replace with the one in the old carb and give it a try. Any easier way ?
Rosco is you car a right hand drive or what ??? The battery seems to be in a different location.... ?

 

[roscoFJ73]

Yes, it's a carbd 3F engine....I had to wait a while for the carburetor and I got it finally from Libya ! There is a lot of 70's series here in Egypt..a lot of them are owned by travel agencies.
My mechanic worked on replacing the carb and he plugged the vaccum hoses, but if there is any pics or manual so I can recheck what he did, would be perfect.
Rosco how can I know if this part is working fine or not ?? I think I will replace with the one in the old carb and give it a try. Any easier way ?
Rosco is you car a right hand drive or what ??? The battery seems to be in a different location.... ?

That part is called the secondary diaphagm. You just dismantle and look for damage.
I though you might have swapped your old one onto the new carb but if its new it probably wont be the problem,

Have you looked t the glass window ,it should be half full at all times.
Look for air leaks at the base of the carb,spray some water.If there is a leak the engine will stumble as it sucks in water.

Yes ,right hand drive,we still recognise the Queen of England

. Most 70 series, diesel or petrol have the battery there in Australia
Here is some engine pics. I hope you can see the vac hoses.
Make sure the wire is connected firmly to the fuel cut solenoid.

 

[Khorrassany]

Hi again,

I was too busy this weekend to work on my car... I guess I will have to recheck :

1-the vaccum hoses
2-the carb base
3-recheck the gas filters again "dirty fuel is very common here "
4-check the distributor settings for any retard or avance
5-tune the carb
If I forgot anything on my list please add.
I will let you now...when I work on it.

Thanks again
Issa

 

[roscoFJ73]

Hi again,

I was too busy this weekend to work on my car... I guess I will have to recheck :

1-the vaccum hoses
2-the carb base
3-recheck the gas filters again "dirty fuel is very common here "
4-check the distributor settings for any retard or avance
5-tune the carb
If I forgot anything on my list please add.
I will let you now...when I work on it.

Thanks again
Issa

The carb glass window,i should be half full at all times.
If dirty fuel is a problem then maybe it needs to be dismantled and the jets blown out with air

 

[Japan4X4]

If it "hitches" just coming off idle and then runs fine check the accelerator pump. This is designed to shoot a spray of fuel in when the throttle plates open suddenly.

It will be obvious with the air cleaner off and the engine on or off while looking down the throat of the carb and pushing open the throttle. No fuel spray = none working pump.

 

[Khorrassany]

I already check the carb glasswindow and it's always half way full. I guess I'm gone have to check the accelerator pump. Can I test it while the engine is off ??

 

[roscoFJ73]

I already check the carb glasswindow and it's always half way full. I guess I'm gone have to check the accelerator pump. Can I test it while the engine is off ??

Yes I think so but if you do it with the engine running you should notice a stumble at the same time if its no good

 

[Khorrassany]

I check everything with my mechanic and it's not a carb problem as I replaced the old with the new one and no change with the hitch. My mechaninc told me it's an engine problem... I need to overhaul the upper part of the engine .... so still thinking what to do !!! hmmmmm

Issa

 

[crushers]

these engines are easy to rebuild, i beleive they are a close relative to the 2F. it will cost about $300 for parts and what ever machining will cost you.
well worth it to do the whole engine at the same time. what usually happenins is you rebuild the upper part of the engine (the head) and then you start to suck oil past the rings usually quite badly.
go for a full rebuild and enjoy the truck for another 300,000 km...

 

[roscoFJ73]

I check everything with my mechanic and it's not a carb problem as I replaced the old with the new one and no change with the hitch. My mechaninc told me it's an engine problem... I need to overhaul the upper part of the engine .... so still thinking what to do !!! hmmmmm

Issa

Sounds like bad valves. Im with Crushers,if you rebuild the head on an old motor it increases the compression and soon you have blow by in the bottom half.
Its a full rebuild or a used engine which is risky

 

[Khorrassany]

I'm dealing with 2 mechanics...one told me i should bore the engine and fit 0.10 pistons. The other one told me just to replace the rings round the pistons "dunno the name in english". And of course I have to overhaul the upper part in both cases.
1st alternative will cost me round a 1000 $
2nd alternative will cost round 250 $

very confused as mechanics here are cheap, but not that good....so it's a bit risky

 

[roscoFJ73]

The 1st alternative is the one I would take. If you do number 2 it will be ok for a few months and the problem will return.

I would also do the bearings and all the seals ect.
Usualy the complete kit is a about $900 for the pistons, rings,bearings seals,valve springs plus the cost of a cylinder rebore.

Mine 3F died just before 300000klms

 

[bigbrowndog]

Your decision may be governed by your budget as you have not indicated what you are prepared to spend. If the head is removed which obviously needs repairs from what you say then the bore can be inspected. You will be able to see what sized lip is on the bore at the top of the piston stroke. Better still if it is measured internally with a micrometer. It is fesable with the 2F that if the motor has been looked after that you can reuse the pistons and give the bore a light hone to deglase it and fit new rings and bearings. The rebore and complete rebuild is better of course but this depends on your budget. If the head is rebuilt and a good job done on a re ring and bearings it should run trouble free for some time.The 2F is a very simple motor to rebuild and is virtually indestructable when driven correctly and serviced correctly.cheers.

 

[crushers]

the ONLY time i rebore is if there is a need. i would budget for #1 (good chance you might need it with that many km) but plan for #2. i have had great luck with #2 if the cylinder walls are "true" as BBD says.
unless the ring groves are worn or the piston has suffered damage then why replace the pistons themselves? of course all new gaskets and bearings must be done.

cheers and good luck

 

[Khorrassany]

I don't want to spend a lot of money, but I don't want to spend a lot of time with my mechanic too !!!
I replaced the rings on the pistons before a couple of years ago so I guess fitting rings again won't be the perfect solution....
"Crushers"What will it cost me if you decided to sell the 3F ? Just to see if I have another option....
"BigBrownDog"I can't inspect the pistons as Crushers says if I only took the upper part apart, so I'll have to take the oil pan apart as well ?
Hmm very lazy to re-bore the engine...but it seems no choice