lunging at 50mph 60mph and 65 mph (1 Viewer)

1978freebornred

78 fj40 LE and 79 fj40 LE w/ stock ac
Joined
Dec 12, 2010
Messages
433
Location
Springfield Mo
 
I drive on the highway occasionally i have stock drivetrain stock axles the only thing that has been done is a shakle reversal... the fj lunges going up hills or when i reach 50 or higher on the speedo i have 33s so it more like 58 whats going on? i push in the clutch and it stops i let off the gas it stops and it goes from running at 2700 rpms to 2200 or less even if i give it hell.
 

1978freebornred

78 fj40 LE and 79 fj40 LE w/ stock ac
Joined
Dec 12, 2010
Messages
433
Location
Springfield Mo
 
i have ran new 3/8 lines and new filter the return and supply lines from the fuel tank are the only ones hooked to the carb carring fuel... did that like 2 weeks ago... fuel pump is probable since its oe i dont know if the real original if so the petina is great on it.
 
Joined
Feb 27, 2011
Messages
22
Location
Casper Wy
Could it be arcing across the dist cap or wires. I've had a miss develop only when the engine was under load. mine was caused by a bad spark-plug wire. It ran fine till you put it to work. What do you mean when you push in the clutch it goes away? does it seem like an engine problem or a drivetrain problem?
 
Joined
Aug 17, 2003
Messages
1,399
Location
granite falls WA.
have you had a look in the tank ? there could be rust and or debris partially clogging the line. i had this happen years ago and i cleaned and lined my tank and haven't had a problem since. you could blow some air through the line to try and clear it and take it for a spin and see what it does. but as you drive you will slowly suck up what you blew out.
 

1978freebornred

78 fj40 LE and 79 fj40 LE w/ stock ac
Joined
Dec 12, 2010
Messages
433
Location
Springfield Mo
 
im assuming drivetrain because wen i push in the clutch it stops lunging but also slows down... the distributor is possible it has electrical tape in it. it has a new gas tank but could be junk in it still.
 
Joined
Jan 25, 2008
Messages
297
Location
Enola, PA.
 
 
im assuming drivetrain because wen i push in the clutch it stops lunging but also slows down... the distributor is possible it has electrical tape in it. it has a new gas tank but could be junk in it still.
Electrical tape in the dizzy? I gotta see a pic of this. Sure sounds like the problem to me.
 
Joined
Feb 12, 2011
Messages
63
Location
ICO, AR
I would think its your fuel pump not having enough power to pull the fuel against gravity. If the lines are bigger than stock lines the pump will have to work harder pumping more fuel to fill a bigger line. I would try a electric fuel pump with more power and see if that solves your problem.

Around $20 will get you a new distributor. If it has tape in it is to seal a crack moisture is still getting in there.


I'm just a noob so take that with a grain of salt. but I had a similar fuel problem on my old 71 ford pu when i was a kid. Left me stuck on a hill with a trailer.
 
Joined
Feb 27, 2011
Messages
22
Location
Casper Wy
If you add throttle does the engine surge and slow down like it is running out of fuel? if it lunges and you back out of the gas for a couple seconds will it immediately do it if you get back into the gas?
fuel starvation and electrical have a different feel from each other. IME crossfiring is much jerkier compared to starvation. I would love to see a pic of the tape in the distributor also :hmm:
 
Joined
Feb 27, 2011
Messages
22
Location
Casper Wy
what engine/trans combination are you running? not that the troubleshooting is that different--unless yours doesn't have sparkplugs! :D
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top Bottom