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Old Feb 12, 2005 | 03:12 AM
  #1  
DeLorean247's Avatar
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From: Pasadena, CA - Granbury, TX
Car: 1982 Pontiac T/A
Engine: 350 Carb
Transmission: TH200c
Engine shake

Hi

Well I have a 82 Trans AM with a weird shake/vibration all the time wile im in park or driving. It changes speed with Rpms but does not become harder.

Its allmost like a missing on one cyl feeling.. when watching the engine it kinda shutters every 2 seconds or so.

Its a new engine with 500 miles, new plugs of course, fuel pump and all the other new engine things but those wouldent seem related..

Today I installed a new cap and rotor and will try new plug wires tomorrow.. It does this about 98% of the time and did not do this atall for the first few weeks of the new engine.. sometimes I start it and it runs perfectly smooth for afew minutes.

It does have a fuel filter in the old carb that is from late in 2001 and was used with the old engine for about 2 months before it gave out.

The car sat for about 3 years with a 1/4 tank of gas does this sound like possible a partially clogged filter?

And when I look down into the carb the fuel is pulsing into the chamber. im not sure how it suposed to look on a carb if this is normal or if it needs to be a steady stream

Also half throttle and full throttle dont really seem like much of a difference.

Thanks Alot For Any Help.
-Michael
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Old Feb 12, 2005 | 03:38 AM
  #2  
Token's Avatar
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From: Toledo, OH
Car: 1992 Firebird
Engine: forged 357
Transmission: 700r4, 2200-2400 stall, vette servo
Axle/Gears: stock pegleg 2.73 drum (temp)
time for a tuneup.
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Old Feb 12, 2005 | 04:57 AM
  #3  
ede's Avatar
ede
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From: Jackson County
i'd check timing, rocker adjustment, vacuum leak, firing order
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Old Feb 12, 2005 | 07:12 PM
  #4  
DeLorean247's Avatar
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From: Pasadena, CA - Granbury, TX
Car: 1982 Pontiac T/A
Engine: 350 Carb
Transmission: TH200c
ok the new fuel filter and plug wires dident help but they were getting old anyway.

I checked the timing and its good changing timing slightly dosent make a difference either. The rocker arms should be fine i got a long block from ATK and they live test the engines and make adjustments but I might endup checking that anyway.

I tripple checked firing order Today when I installed the new wires. Im sure Vacuum could be my problem.. I have no vac at my EGR tap on the carb is this normal at idle? What a good way to check for a leak?
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Old Feb 14, 2005 | 02:43 AM
  #5  
DeLorean247's Avatar
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From: Pasadena, CA - Granbury, TX
Car: 1982 Pontiac T/A
Engine: 350 Carb
Transmission: TH200c
Ok checked my rocker arms today.. They felt ok but I went ahead and re did them all just to be sure.

I cant find any vacuum leaks either. Only thing I can find as not working is my fan clutch it stuck on full.
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Old Feb 18, 2005 | 03:40 AM
  #6  
DeLorean247's Avatar
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From: Pasadena, CA - Granbury, TX
Car: 1982 Pontiac T/A
Engine: 350 Carb
Transmission: TH200c
Update:

I still am getting the shaking through all rpm ranges.
And my idle changes on its own.. The car seems to run the best for the first 30 seconds or so. then the idle gets low like it wants to stall. Then after driving it will be a little over 1k. Im pretty sure my cat is shot..

The cars Exhaust smells like it did with the old engine.
The kind of smell that hangs in your clothes for a while kinda matalic smell/taste gets on you. I'm going to replace the cat in the next week but want to know if I should still try to fix my problem other ways till then.

Or does this sound like it would be the cat?


I did a search and it seems that a clogged or dead cat would cause this idle fluctuation but it dose not glow or keep me from going faster then 20mph. But I do have trouble getting up to highway speeds.. it seems like itl go about 65 and i could push harder but it dosent feel right.

Thanks for any help.
-Michael
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Old Feb 18, 2005 | 07:20 PM
  #7  
sellmanb's Avatar
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Joined: Jul 2004
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From: Tigard, Oregon
Car: '86 Berlinetta
Engine: 350
Transmission: 700R4
still using the stock exhaust eh? lol

you can use my style of logic.. "oh, I think my cat is shot, guess I ought to order that cat-back system and a high flow cat to go with it then!" lol.
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Old Feb 18, 2005 | 09:10 PM
  #8  
DeLorean247's Avatar
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From: Pasadena, CA - Granbury, TX
Car: 1982 Pontiac T/A
Engine: 350 Carb
Transmission: TH200c
lol I like your logic.

Today I went and got the cat replaced. It still shakes and the idle still acts up but. YAY! it dose not smell anymore. it has a new smell but I fig its just packing fluid of some sort and will burn off im sure.

Still trying to fig out the other issues ill post anything I find.
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Old Feb 19, 2005 | 02:39 PM
  #9  
sellmanb's Avatar
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From: Tigard, Oregon
Car: '86 Berlinetta
Engine: 350
Transmission: 700R4
could perhaps be a motor mount.
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Old Feb 19, 2005 | 03:44 PM
  #10  
89RsPower!'s Avatar
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Joined: Apr 2002
Posts: 3,552
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From: New Jersey
Car: 86 Corvette, 89 IROC, 1999 TA
Engine: 350, 350, LS1
Transmission: 700r4, 700r4, T-56
Axle/Gears: 3.07, 373, 4.10
Your not using old gas still are ya? my car did the same thing last time I let it sit for about 8 months, shook aweful, syphoned the gas out, saved it for the mower, and put new gas in and it ran fine.
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Old Feb 19, 2005 | 05:23 PM
  #11  
DeLorean247's Avatar
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From: Pasadena, CA - Granbury, TX
Car: 1982 Pontiac T/A
Engine: 350 Carb
Transmission: TH200c
HI

It was old gas at first.. But I have used 3 or 4 full tanks since.
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