40 Bog Down - help pls

Joined
Mar 27, 2003
Messages
378
Location
North Georgia, USA
Hey all
So I a little perplexed.
‘78 FJ40

I replaced the fuel tank, all lines, fuel filter.
Put a new inline electric pump to help with the orig factory fuel pump

Prior to me replacing the tank, lines etc she was running fine

Now after all the new equipment…she bogs down going about 40 slight incline and uphills only… to the point of stalling

Feels like secondary carb fuel starvation but I don’t get it. I replaced the old fuel delivery stuff witn the EXACT same setup …just new stuff

I did not replace the factory mech fuel pump. I may replace that…but I have no idea why it’s starving for fuel uphills

Any ideas ??

FYI - The fuel filter looks good and all vacuum hoses connected and distributer cap looks ok
 

ceylonfj40nut

Waiting for Barn Time
SILVER Star
Joined
Jan 11, 2015
Messages
4,814
Location
TX
Did mechanical fuel pump work on inclines?
 
Joined
Mar 27, 2003
Messages
378
Location
North Georgia, USA
Did mechanical fuel pump work on inclines?
Yes old set up worked fine
Old set up was mechanical + inline elect

New set up is same

I’m wondering if my mech fuel pump
May be bad??

It just doesn’t make sense because nothing changed ffom old to new set up except new equipment
 
Joined
Mar 10, 2005
Messages
1,346
Location
CT
If the mechanical fuel pump works, why install an electrical fuel pump?

Maybe the 2 fuel pumps are the problem.
 

OSS

SILVER Star
Joined
Jun 30, 2017
Messages
4,683
Location
Oblivion
When fuel system parts get replaced, gunk in the old parts can get dislodged and end up in the carburetor. Just replacing a fuel filter can do it.

The same symptoms as OP happened to me years ago, (carbed FJ60) driving up an incline would make the engine sputter.

I removed the carburetor and inspected the float bowl - and low and behold there was a tiny piece of junk floating around in the bowl which apparently would get sucked up against the primary jet when the carburetor was tilted back - when going up a hill.

I cleaned out the bowl and put the carburetor back together- and the engine ran normally afterwards.
 
Joined
Mar 27, 2003
Messages
378
Location
North Georgia, USA
When fuel system parts get replaced, gunk in the old parts can get dislodged and end up in the carburetor. Just replacing a fuel filter can do it.

The same symptoms as OP happened to me years ago, (carbed FJ60) driving up an incline would make the engine sputter.

I removed the carburetor and inspected the float bowl - and low and behold there was a tiny piece of junk floating around in the bowl which apparently would get sucked up against the primary jet when the carburetor was tilted back - when going up a hill.

I cleaned out the bowl and put the carburetor back together- and the engine ran normally afterwards.
Thanks
I’ll take a look at this
 

bkfj40

Wishin i was in Wydaho
SILVER Star
Joined
Apr 5, 2002
Messages
3,461
Location
new erection, va
I would ditch the elec fuel pump. You don’t need it. The factory mechanical pump has driven cruisers around the world.

And check the bowl

I had an old 55 years ago that would bog down after changing the fuel filter. Turns out that there was a lot of rust in that fuel tank and it clogged the filter.
 

Users who are viewing this thread

Top Bottom