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Old 06-28-2009, 09:01 PM   #1
jdfrmnt
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time to junk the pos

i keep failing smog hi ho i find low vac and a leak at the manafold and cab replace all gaskets and vac only increases 1/2" any ideas befor i set this pos on fire
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Old 06-28-2009, 09:16 PM   #2
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Re: time to junk the pos

i forgot to say 383 mild cam q jet headers
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Old 06-28-2009, 09:39 PM   #3
tecky11
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Re: time to junk the pos

one more question year of truck is?
make of truck is?
model of truck is?
once we these asners we can better help you
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Old 06-28-2009, 10:47 PM   #4
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Re: time to junk the pos

Did you surface the intake?
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Old 06-28-2009, 11:42 PM   #5
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Re: time to junk the pos

what kind of vacuum readings are you getting at an idle?

timing? vacuum advance? Does the engine respond to the idle mixture screws?

Where exactly is it failing, and what type of testing do they do?
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Old 06-30-2009, 09:20 PM   #6
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Re: time to junk the pos

Get insurance through Haggerty and you won't have to smog it anymore.
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Old 06-30-2009, 10:19 PM   #7
jdfrmnt
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Re: time to junk the pos

the truck is a 70gmc 1/2 ton 383 stock heads mild cam q jet perfomer intake headers idle set at 800 idle screws set at 3 turns out timing set to 6btdc the intake was replaced with the gaskets changed the carb and no change even with the low vac can still get the idle down to 250im out of ideas so right now i am ready to get somthing pre 66
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Old 07-01-2009, 12:15 AM   #8
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Re: time to junk the pos

Have you sprayed carb cleaner around it to see if you have a leak?
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Old 07-01-2009, 01:01 AM   #9
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Re: time to junk the pos

jdfrmnt, if you junk ur 70 you might have the same issues with previous owner viruses.
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Old 07-01-2009, 01:28 AM   #10
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Re: time to junk the pos

where are you geting your vacuume signal? if you are using a ported vacuume sorce, then you should have verry little to no vacuume on a guage. but if you have manifold vacuume and no vacuume,id say you got more going on. id check the idle screws, i only half to adjust mine out 1 1/2 turns out. id also look at the guage to see if it wiggles side to side indicating a valve problem. id also check for a plugged exhaust. if you can get the idle down to 250 still, id lean twards the exhaust, thinking maybe a muffler came apart or maybe someone stuffed somthing up the pipe. ... just my 2 cents ... hope you find it !

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Old 07-01-2009, 10:48 AM   #11
prostreetC-10
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Re: time to junk the pos

You can always do what I did and move to an area that doesn't have smog requirements.......but it might be easier to junk it!
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Old 07-01-2009, 10:52 AM   #12
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Re: time to junk the pos

Quote:
Originally Posted by Copperman View Post
Get insurance through Haggerty and you won't have to smog it anymore.
Just went on their website and got a quote for my 65' Chevelle and 65' C10. Are these guys for real? Cause that's about 60% of what I'm paying with Farmers.

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Old 07-01-2009, 11:26 AM   #13
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Re: time to junk the pos

From what I understand is that they rate the vehicles as very limited use. I saw them on "my classic car" and they did ........ooops, I think I'm thinking about Grundy worldwide. I guess you could always do a comparison. It's grundy.com
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Old 07-02-2009, 06:39 AM   #14
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Re: time to junk the pos

Quote:
Originally Posted by MacAttack View Post
Just went on their website and got a quote for my 65' Chevelle and 65' C10. Are these guys for real? Cause that's about 60% of what I'm paying with Farmers.

Mac.
Its probably right. It costs me $180 a year for my stock 1920 model T and my wifes 71 Duster--this is through haggerty---and the vehicles are stock. When i had my modified dart only on the policy, it was about $160 for itself. The terms are limited use though, it is not meant for daily driven cars.

Anyway, back to the OP. Maybe i misunderstood some of your posts (it was hard to read without proper grammer/punctuation). What part of the tests specifically are you failing? You may have to retard the timing and lean the crap out of it to the point it runs horrible just to pass it. Mild cam doesnt really say a whole lot, but i will assume something in the 214/220 @.050 range for the duration---but remember, the more overlap it has, the more reversion of intake charge going out the exhaust at lower idle speeds.
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Old 07-02-2009, 10:46 PM   #15
jdfrmnt
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Re: time to junk the pos

im failing ho at idle the rest is real low already retarded the timing and leaning it out no help just mad it worse so im lost
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Old 07-03-2009, 04:14 PM   #16
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Re: time to junk the pos

I hope you don't take this the wrong way, no insult intended.


I had the same problem and got so damn frustrated.

I finally swallowed my pride and took the truck in to my dad's mechanic, he hooked it up to an analyzer and later that afternoon I picked the truck up, took it to the smog test center and it passed way easy. All levels were way below mandated levels.

I'll do a tune for cruzin' around, but for smog testing I always take it in...
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Old 07-06-2009, 10:40 AM   #17
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Re: time to junk the pos

Quote:
Originally Posted by jdfrmnt View Post
im failing ho at idle the rest is real low already retarded the timing and leaning it out no help just mad it worse so im lost
Lean mixtures take a longer time to burn, so you might need to advance the timing.

It is possible to lean it out so far that you get a lean miss, and send un-burnt fuel out the exhaust.
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Old 07-07-2009, 01:24 AM   #18
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Re: time to junk the pos

another little trick just to pas emissions is to pour a bottle of rubbing alcohol intho the tank before you go for testing
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