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Please Help!!! Rochester Problems out the Ying Yang

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Old 04-03-2004, 09:32 PM
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hirevroller
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Default Please Help!!! Rochester Problems out the Ying Yang

OK so I got my qjet rebuilt and dropped it on. I have it running ok but it still seems to be getting way to much fuel I have the garage door open and my eyes are burning. Now the two screws on the front bottom of the carb I have adjusted according to what people have told me they are both out 1 full turn. Now I have adjusted these different ways and still lots of burn off. is there another setting some where I aam missing? and these screws to the front I thought adjust the amount of fuel? when turned in does it reduce fuel or increase? In less out more? I am so frustrated because I bought this car and took buddys word that it ran and it did but the carb was shot. and after the rebuild I still get lots of fumes and smoke in the tails which seem to be fuel smells really rich and just tonight heard a bit of a bottom end knock. NOT HAPPY! Please help me any info would be appriciated. As it is looking as if my driving season is a motor rebuild season. Please guys.

Thanks to all.
Steve :( :sad:
Old 04-03-2004, 10:00 PM
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page62
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Default Re: Please Help!!! Rochester Problems out the Ying Yang (hirevroller)

Get a copy of Lars QJet "white paper" over at http://www.corvettefaq.com
And perhaps Lars himself will make an appearance. :cheers:
Old 04-03-2004, 11:07 PM
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lars
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Default Re: Please Help!!! Rochester Problems out the Ying Yang (hirevroller)

There are at least a dozen different issues that can cause the problems you're describing...

First, you want to make sure your ignition system is set up correctly. I always tell people that 90% of all "carb problems" I see are actually ignition and timing related issues. If your timing is not right, the effects on manifold vacuum and other engine parameters will make it seem like a carb problem. You cannot tune out ignition issues by playing with the carb. So before you do anything with the carb, make sure you're set up for 36 degree total timing, make sure your vacuum advance control system is working right, and make sure the advance system is operable. You should be set up for about 12-16 degrees initial timing without the vacuum advance.

Once this is verified, you can move on to the carb.

If the carb rebuild has not been performed correctly, you can have a bunch of issues going on. A carb that is running rich with the idle mixture screws at only 1 turn out has a problem. Your carb should run clean and lean with the screws at 4 full turns out (out is richer - in is leaner). If you're rich at 1 turn, you have a problem.

Common problems for this symptom include:
Float level too high (needs to be at .420 for your year application)
Power piston stuck or incorrectly adjusted
Incorrect throttle plate gasket used
Needle clip installed incorrectly in float arm
Incorrect base gasket
Vacuum leaks
Plugged idle metering circuit
Primary rods not engaged in jets
Secondary throttle plates not seated in bores

Tag me back if you need assistance.

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