hesitation, lurching??

Joined
Jan 18, 2005
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378
Location
Magnolia, TX
ok well my mechanic is out of town, and im tryin to find a reason for a recent development of my cruier.

it idles perftect and sounds fine, but has soon as u put it in gear and start driving, no matter what gear, between 2000 - 2800, the truck lurches/hesitates slightly. also it is very hard to get above 55mph

any ideas?
 
Joined
Oct 18, 2004
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745
Location
Rockville, MD
Fuel pump? Check the window on the front of the carb to see where the level of the fuel is. If it's low this may be that your float is set low and your carb just isn't getting gas.

Chris
 

chitown40

 
 
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Feb 9, 2004
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Buffalo Grove, IL
I'll bet your heat riser flapper stopped flapping, causing an exhaust restriction. When it's cold, start her up, then watch the coil spring contract. If it doesn't, then that is you rprob. If it does, then start checking your fuel supply/delivery system and carb. This happened to me about a month AFTER I reinstalled my manifolds and I had to rig it open all the time.
 

60wag

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Oooo.. I like the stuck heat riser idea.... but I'm I'm still going to toss out my standard answer: leaking seconadry diaphram on the carb. It s probably easier to try to wedge the heat riser open though for a test than to check the diaphram. The failing fuel pump is a good call too.
 
Joined
Jan 18, 2005
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Magnolia, TX
well i had the same reactions. i checked fuel supply and pump. its good and the heat riser thing i dont know if mine can do that. i have the JToutfitters 6 in to 1 performance header.

But the float thing maybe. how would i check that?
 

BlueCruiser84

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Nov 1, 2004
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Had the same symptoms and a problem i found. There are so many things that go wrong that cause a lurching that it is hard to diagnose. The two things i found that were making mine hesitate were...
the EGR valve sticking, and the primary jet on my carb was REALLY messed up.

When the EGR was messed up it would hesitate but it would also get this terrible bucking when you take off, and i wouldnt be able to go over 60 mph . After i fixed that it just had a slight hesitation right at start up, and i fixed that with new secondary and primary jets.

Brian
 

chitown40

 
 
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Feb 9, 2004
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Well, if you got the header my theory is now completely disproven. :D

Check the four brass ports at the base of the carb..might have some gunk or a piece of broken vac hose in there. If the secondary diaphragm is leaking I would imagine you'd create a sort of vac leak that would make it idle poorly. But that's just my experience when mine stuck part way open.

I like the partially clogged jet theory. Try some carb cleaner and blow out the passages you can access in the carb. Also might consider a clogged cat. It would create a symptom similar to the restricted manifold w/ the heat riser.

Oh yeah, Sox just won! Woo hoo! Go Chicago! :D
 
Joined
Aug 28, 2003
Messages
347
Location
Pearland, TX
BlueCruiser84 said:
Had the same symptoms and a problem i found. There are so many things that go wrong that cause a lurching that it is hard to diagnose. The two things i found that were making mine hesitate were...
the EGR valve sticking, and the primary jet on my carb was REALLY messed up.

When the EGR was messed up it would hesitate but it would also get this terrible bucking when you take off, and i wouldnt be able to go over 60 mph . After i fixed that it just had a slight hesitation right at start up, and i fixed that with new secondary and primary jets.

Brian
Same thing with our old 60-EGR
 
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