90 YJ 4.2L random power loss on hills
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Re: 90 YJ 4.2L random power loss on hills
Steve,
I think that you are onto something with the float level. I do notice it
bogs down and seems to choke out the exhaust. It seems much more prominent
on long hill climbs at high speeds. Maybe this is suggesting that the float
level is mis-adjusted and causing the carb to really lean out. I really
thought that I had the float adjusted properly when I rebuilt it in early
Aug. However, last weekend (after the rebuild), I noticed that the fuel
line where it attached to the carb was leaking, I tightened it up, both
line and the brass fitting which goes into the carb (the brass fitting which
holds the float needle valve). Now I am wondering if by tightening up the
brass fitting, did this through off the float level enough to cause this
problem (I never noticed this bogging problem until after I tightened up the
brass fitting).
What do you all think? And thanks much for your time.
mpv
"Steve Cowell" <scowell@sbcglobal.net> wrote in message
news:3cn1b.2996$oJ2.49@newssvr22.news.prodigy.com. ..
>
> "Michael Vincenty" <mvincenty@adelphia.net> wrote in message
> news:p8e1b.5677$Nc.3544698@news1.news.adelphia.net ...
> > All,
> >
> > Hope you can help. My 90 YJ with a 4.2 six has just developed a
periodic
> > power loss problem when cruising at highway speeds and having to climb a
> > slight hill. It seems to happen in 4th gear, RPMs seems to remain
steady
> at
> > 200 RPMs. It seems like it is fuel starved but I really cannot tell.
>
> You probably mean 2000.
>
> No problem on the flats? At higher speeds? I'd guess you have too much
> fuel in your float bowl... either a stuck/bad needle and seat, or
adjustment
> needed on the float height. Does it bog, or backfire/pop? If it leans
out,
> you should get backfire; my bet is rich. Look for black smoke from the
> tailpipe in failure mode.
> __
> Steve
> .
>
>
I think that you are onto something with the float level. I do notice it
bogs down and seems to choke out the exhaust. It seems much more prominent
on long hill climbs at high speeds. Maybe this is suggesting that the float
level is mis-adjusted and causing the carb to really lean out. I really
thought that I had the float adjusted properly when I rebuilt it in early
Aug. However, last weekend (after the rebuild), I noticed that the fuel
line where it attached to the carb was leaking, I tightened it up, both
line and the brass fitting which goes into the carb (the brass fitting which
holds the float needle valve). Now I am wondering if by tightening up the
brass fitting, did this through off the float level enough to cause this
problem (I never noticed this bogging problem until after I tightened up the
brass fitting).
What do you all think? And thanks much for your time.
mpv
"Steve Cowell" <scowell@sbcglobal.net> wrote in message
news:3cn1b.2996$oJ2.49@newssvr22.news.prodigy.com. ..
>
> "Michael Vincenty" <mvincenty@adelphia.net> wrote in message
> news:p8e1b.5677$Nc.3544698@news1.news.adelphia.net ...
> > All,
> >
> > Hope you can help. My 90 YJ with a 4.2 six has just developed a
periodic
> > power loss problem when cruising at highway speeds and having to climb a
> > slight hill. It seems to happen in 4th gear, RPMs seems to remain
steady
> at
> > 200 RPMs. It seems like it is fuel starved but I really cannot tell.
>
> You probably mean 2000.
>
> No problem on the flats? At higher speeds? I'd guess you have too much
> fuel in your float bowl... either a stuck/bad needle and seat, or
adjustment
> needed on the float height. Does it bog, or backfire/pop? If it leans
out,
> you should get backfire; my bet is rich. Look for black smoke from the
> tailpipe in failure mode.
> __
> Steve
> .
>
>
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