1973 fj40 idle issues RTH (1 Viewer)

[Tennessee80]

Hi mud,

I put RTH on the thread because I am trying to get my truck running and driving for GSMTR this next weekend... Here is a list of what I have done to the truck and the symptoms at the top of the thread...

1973 fj40
Stock 1F engine
Rebuilt head (not bored over)
HEI distributor (timing is set correctly, or so we think)
Weber 38 carb
Stock fuel pump (old)
New manifold gasket
No exhaust AT ALL (not even down pipe...)

The truck will start and run if you keep your foot on the gas, but will not stay running when you let off the gas. You can set the Weber to high idle mode and it will run but that is ridiculous because it is so high.

Any ideas what could be happening to prevent the truck from settling down and not idling smoothly? Do i need a new fuel pump possibly, and do I need to run an electric fuel pump with the Weber?

I am getting exhaust installed this Wednesday.

Any advice appreciated.

thanks,

 

[1911]

Any ideas what could be happening to prevent the truck from settling down and not idling smoothly?

"No exhaust AT ALL (not even down pipe...)"

Report back how it is running after you get the exhaust installed.

 

[graham5david]

Webers run at 3psi. Do you have a pressure regulator between the pump and carb. Definitely put your exhaust on.

 

[Tennessee80]

Webers run at 3psi. Do you have a pressure regulator between the pump and carb. Definitely put your exhaust on.

No I don’t have a pressure regulator. Any suggestions on what to get?

 

[Tennessee80]

I was told by a few people that I should be able to get it to idle ok without exhaust, but it makes sense to have basic components like exhaust installed before any real troubleshooting begins.

I’ll report back Wednesday afternoon…!

 

[graham5david]

I just think it would be so loud it would be hard to hear timing issues etc...

 

[graham5david]

No I don’t have a pressure regulator. Any suggestions on what to get?

You can get a cheap inline one at any autoparts store. Then order a better one later. Go to the redline website they have all the Weber manuals and tech support

REDLINE - Serving the U.S., Canada, Central and South America for over 30 years

 

[Tennessee80]

It looks like a fuel pressure regulator could be another good place to start, as there are multiple threads about Weber 38 sensitivities to incoming pressures…

Could that cause the truck to stumble and choke out while it’s trying to idle?

 

[ToyotaMatt]

It looks like a fuel pressure regulator could be another good place to start, as there are multiple threads about Weber 38 sensitivities to incoming pressures…

Could that cause the truck to stumble and choke out while it’s trying to idle?

i have a complete NOS Webber land cruiser kit , if your in need pm me ....please

 

[Tennessee80]

Update:

-The truck is now idling, and I still have no exhaust.

Another cruiser guy I have been in contact with suggested using an inline fuel filter from a Jeep CJ7, and while that sounds odd, the filter has a 3 psi output max setting on it, and a return port that kicks any extra fuel (over 3 psi) back to the fuel tank.

The WIX part number is: 33040

I tried it, and amazingly enough, for $10, my truck immediately responded and ran smoothly. Once I get the exhaust on it on Wednesday we can really fine tune the idle...

Anyway, interesting mod, and relates to the suggestion that @graham5david had about a pressure regulator...

cheers

 

[graham5david]

Update:

-The truck is now idling, and I still have no exhaust.

Another cruiser guy I have been in contact with suggested using an inline fuel filter from a Jeep CJ7, and while that sounds odd, the filter has a 3 psi output max setting on it, and a return port that kicks any extra fuel (over 3 psi) back to the fuel tank.

The WIX part number is: 33040

I tried it, and amazingly enough, for $10, my truck immediately responded and ran smoothly. Once I get the exhaust on it on Wednesday we can really fine tune the idle...

Anyway, interesting mod, and relates to the suggestion that @graham5david had about a pressure regulator...

cheers

Glad it worked for you. Those Webers are pretty responsive once you get them tuned.