Author Topic: New 350 runs TERRIBLE!  (Read 18172 times)

Offline 327power

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New 350 runs TERRIBLE!
« on: October 25, 2010, 06:44:39 pm »
 >:(Well, I have about 1500 miles on my new Goodwrench 350. The thing is I could NEVER get it to run right. It shakes horribly and just runs like wants to die. I had to raise the idle just so it won't stall at traffic lights! It has a Holley 600 4bbl. I've tuned the carb left and right with no results.
Done timing too. I'm thinking it's that crap 4bbl. Does anyone else agree that Holley's just suck? I'm going to try an Edelbrock 600 next. If that doesn't make it run right, I'm going to sell my C10 dirt cheap and buy a nice 77 F100 down the street.
So ultimately, want does anyones opinion on my carburetor situation? Any help is awesome! Thanks!
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Offline 4x4orbust

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Re: New 350 runs TERRIBLE!
« Reply #1 on: October 25, 2010, 06:57:01 pm »
a lot of people worship the holley,  i am not one of them.   I had a holley 600 on my 73.  i tried tuning that thing 100 times, never could get it just right.   i put a quadrajet back on and never looked back.  I still have that quadrajet on my 82. gonna rebuild it soon tho.
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Offline eventhorizon66

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Re: New 350 runs TERRIBLE!
« Reply #2 on: October 25, 2010, 07:01:41 pm »
When you say you've done the timing, what did you set your timing to?

Some carbs do suck out of the box (float setting off, poor jetting, crap in the bowls), but I doubt your carb can't be tuned to run very well, no matter what it is.  When you tuned the carb "left and right", what all did you try?

Can you give a better description of everything the engine is doing?

My Goodwrench runs 15 degrees initial and 36 total and could take more.  And with a 1406 Edelbrock carb it runs far from what I'd like it to as well.  I suspect retarded cam timing, and an inaccurate timing mark (either on the balancer or where the crank is machined for the woodward keys).  I am positive about very low compression, the worst SBC heads GM ever made.  Nontheless, I have it running acceptably for day to day driving (doesn't die, idles great at 650, adequate power, 15-17 mpg).
« Last Edit: October 25, 2010, 07:04:06 pm by eventhorizon66 »
'85 C10 SWB 350 700R4 TKO600

Offline Captkaos

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Re: New 350 runs TERRIBLE!
« Reply #3 on: October 25, 2010, 07:59:14 pm »
ditto, need more information.

BTW, I hate Holleys, but I don't like any carbs.  EFI only.  LOL

Offline 327power

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Re: New 350 runs TERRIBLE!
« Reply #4 on: October 25, 2010, 08:41:50 pm »
I was thinking...does anyone think low fuel pressure could be the problem? I have a crappy $15 fuel pump from Autozone. When the thing is idleing, it looks like there is very little (1/3rd) fuel in the fuel filter. When the engine is off however, it is full. Weird. So what do you think?
Oh yeah..I tuned the thing the best I could via a vacuum gauge.
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Offline screamin86

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Re: New 350 runs TERRIBLE!
« Reply #5 on: October 25, 2010, 09:08:27 pm »
Are you 100% sure your dizzy isn't a tooth off or timming just off very badly?
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Offline 327power

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Re: New 350 runs TERRIBLE!
« Reply #6 on: October 25, 2010, 09:29:05 pm »
Yeah... The timing is right where it brings the most vacuum. Its weird I even changed the intake gaskets. After that, it ran awesome...then I shut it off. About half an hour later I started it back up to take a test drive and it's been horrid ever since. Nothing seems to help either.
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Offline screamin86

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Re: New 350 runs TERRIBLE!
« Reply #7 on: October 25, 2010, 10:15:56 pm »
Good plugs and wires?
86 k10 lwb 4x4:350 .040 214/224 444/466 112lsa performer rpm 1406 lt's summit racing th350 2800stall
03 yukon xl:tint debadge full boltons
86 ta:lm7 hot cam boltons

Offline 1980c10

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Re: New 350 runs TERRIBLE!
« Reply #8 on: October 25, 2010, 11:06:02 pm »
take out your spark plugs and see how they look i.e. too dark/light etc. see if one is differant than the rest, check your timing with a timing light, rule out a spark problem if you can.  then check your fuel pressure. with a problem that has many potential causes you need to start ruling things out. 

Offline Psycho71

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Re: New 350 runs TERRIBLE!
« Reply #9 on: October 25, 2010, 11:22:26 pm »
Yeah... The timing is right where it brings the most vacuum. Its weird I even changed the intake gaskets. After that, it ran awesome...then I shut it off. About half an hour later I started it back up to take a test drive and it's been horrid ever since. Nothing seems to help either.


Hmm, maybe getting somewhere. Have you thoroughly checked for vacuum leaks? A little carb cleaner sprayed around those intake gaskets maybe? Could even be a leak into the lifter valley area that would be hidden from you. If it ran good once, it can again. The trick is gonna be finding out what changed in that cool down session. And I'm almost willing to bet your problem aint gonna be the carb. Either a vacuum leak or a timing issue is where my money is.  

If you have a fuel pressure issue, it's likely you have too much pressure, misadjusted float height, or trash in the needle and seat that is allowing fuel to run into the intake unregulated. If it won't idle properly, it's very unlikely to be too low of pressure if it will actually run under throttle. If it ain't got enough fuel just doin' nothing, it certainly aint gonna do the job while you're workin' it. It would stumble, lean out, and fall on it's face.

 Does your fuel filter lay on it's side? if so, that's a common sight, the filter only being half full or so. If you mounted it vertically where the fuel enters the bottom and exits the top, it will stay full all the time. As it is, you're just not moving enough liquid thru it to burp the air out of the filter. No biggie, I've seen it before and ran them 1,000's of miles that way. Easy fix for that...Get rid of the see thru fuel filter.

These are just my experiences. Food for thought so to speak. Take, or disregard, as you wish.

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Offline Irish_Alley

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Re: New 350 runs TERRIBLE!
« Reply #10 on: October 26, 2010, 04:31:20 am »
what idle do you have it set at for it not to die and what was it before? does it have a choke?
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Offline Grim 82

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Re: New 350 runs TERRIBLE!
« Reply #11 on: October 26, 2010, 09:16:20 am »
+1 for vacuum leak.
Re-check your intake. I retired a perfectly good Edel 1406 in favor of a Holley because my intake leaked, but spraying carb spray around it didn't do anything. I fixed it accidently when I swapped in a performer intake.
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Offline Captkaos

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Re: New 350 runs TERRIBLE!
« Reply #12 on: October 26, 2010, 10:01:40 am »
The fuel sight glass will never be full, so that has nothing to do with it.  
Gas fills the bowl and keeps it full when running.  It is not a pressurized system like you are thinking.

Holleys need about 5-7lbs to operate.

Offline Dr_Snooz

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Re: New 350 runs TERRIBLE!
« Reply #13 on: October 26, 2010, 12:39:05 pm »
+3 on vacuum leaks. What is your vacuum gauge doing? Is it steady? What's it reading for in/Hg? Definitely sounds like a vacuum leak to me.
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Offline VileZambonie

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Re: New 350 runs TERRIBLE!
« Reply #14 on: October 26, 2010, 04:33:08 pm »
Since you're gonna sell it for a Ford I'll give you $50 bucks for it  ;D

Make sure you don't have #5 and #7 wires crossed. Triple check becuase people tend to commonly make this mistake.
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