Heat Related Stutter

Oh yeah, I remember, it's that little passage about midway on the intake right?

I'm sorry, I should've told you earlier, mine is a vortec model part number 2716, non-EGR.

I visually verified this because I noticed when we put the intake back on that the passage was never machined out.

Sorry man, I'm just so frazzled right now that I'm not thinking straight.

Ok, I just put the 3/8" gasket under it and took it out for a test, it's not as hot right now as it was earlier but it's still doing it but it's a lot better than what it was.

While I had the carb open Saturday I noticed that it had .092 secondary jets, I thought this was a little odd since the primary jets are .098 (of course the metering rods provide a slight blockage).

So tomorrow I think I will try the .101 jets in the secondary, the carb manual shows this to be two stages rich but the .098 jets are in the primaries so that's the closest step.

Also, and I'm really going out on a limb here, I have an open air element, and I was thinking that it was possible that the high velocity air coming into the engine compartment from the fenders (I don't have those little flappers) and of course the front, might be "sucking" fuel out of the bowls? I noticed a couple of years ago when I had just put the engine in and didn't have the hood on yet that when I'd go WOT it would act like it was starving and my windshield would get fuel all over it, I thought it was just because I wasn't running a hood but I guess it could still be doing the same thing right?:sos:
 
An update

I decided to go back with the .092 secondary jets, finally got my damn vacuum can and installed it, pulled the 3/8" gasket and figured "What the hell, what's one more 1/8" and installed a 1/2" Mr. Gasket stacked carburetor heat shield.

It's cooler today than it has been so I took her out and ran her at 70 in third for about ten minutes, got the temp up to about 200-210, turned off the highway onto a farm road and nailed the shit out of it, ran her all the way up clear to 5,000 RPM in third, no problems, no stutters or hesitations whatsoever. I'm still reserving final judgement for a hot day when I can really put it through it's paces but it seems to be fixed.:bounce:

Thank you so much for your help on this, if we ever meet I'll have to buy ya a couple.:drink:

NOW I HAVE ANOTHER ISSUE!

It's a low RPM to high RPM issue, when I'm in first at low RPM and I nail it she almost instantly goes to her shift point and becomes hard to steer, it feels like the rear tires are trying to pass the front tires.

Don't worry about offering any suggestions to fix this, I think I can take care of it on my own.FIREdevil.gif
 
The hot day came...

It still does it, just not as bad.

I figured I'd check the fuel pressure, see if maybe that was the problem, I went down to O'Reilly's to see if they had a cheapie fuel pressure gauge. The only gauge they had was a Mr. Gasket and they wanted 20 bucks for it, they wanted more for the Mr. Gasket adjustable fuel pressure regulator, as I stood there pondering what to do while looking at my allowance from my meager weekly paycheck I looked down and saw this.

http://www.sdparts.com/product/E8134/UniversalFuelLineFilterKitBlueAnodizedFilter.aspx

I had seen it at that same page online and had been wanting to get one since the other night, I sent the link to SaudiVette, who has been having some problems of his own and said it worked great for him, O'Reilly's wanted thirty bucks for it sans filter.

That's when my A.D.D. kicked in, I forgot all about my "heat related stutter" problem, I guess it was all the chrome that did me in, what can I say, I'm only a man. Anyway, I brought it home, modified my heat shield to allow it to fit and then ended up having to re-do my fuel line from the pump to the carb.

It's not very hot today, it's about 77-80 degrees with a light breeze, so I took her out to see if I could maybe figure out how to fix this stutter, I usually have my best ideas while driving. I had thought of mounting a little box around the carb with some 1/2" steel line circling the carb, I could then plumb that steel line in with the A/C compressor that I still have, re-install the condenser, and charge it up with 134-a and set up the system so that it's on all the time, keeping my carb nice and frosty cool. That would fix any heat related issues right?

Then I thought to myself, "Damn Brian, you ARE a true car-guy, here you are thinking about an A/C system for your carburetor and not for you." Then I looked at my temperature gauge, 200*.

That's the temp she ALWAYS does it at, so I downshifted and held the RPM up for a while so she'd get just a little hotter, she did, then I stopped for about as long as one would sit at a stop light, I envisioned that bastard in the Mach 1 beside me, then I nailed the throttle.

She pulled all the way through third gear, which, anyone with a 700-R4 will tell you is well over 100 and easily a quarter mile.

I think I might have just solved my problem boys, I don't know how, but I'm guessing that it was the rubber/stock steel line/rubber combination fuel line I was running. Or maybe it was that my drop-base air filter slightly kinked my fuel line. Maybe it was that the fuel filter was horizontal where it's now vertical inlet/outlet. I don't know, and I can't figure it out, maybe it's not really fixed and I'll find all that out on another hot day this week beside that damned Mach 1 (he always jacks with me when the engine is good and hot, never after I've just come up to temp, it's infuriating).

Anyway, I just figured that I'd post up another chapter in this saga in hopes that if some other unlucky bastard ever has this problem, it just might help him.:drink:
 
You are truely a car guy....always thinking about some way to fix something!

Glad to hear you got it sorted out:drink:
 
you would be surprised how much regular rubber fuel line swells. glad you fixed the problem and all steel lines are the only way to go....any thing less is just amateurish.....
 
Two freakin' years later I've FINALLY fixed my heat-related woes.

I did it with a $50 electric fuel pump from O'Reilly's, mounted it back there where the spare tire is SUPPOSED to go (I've never ran one) and I can say that without a doubt, no question what-so-ever that it is fixed.

I know, I know, I've said that before but really, she's there. Today was hot enough to test it too. Every time I nailed it she was all there 100% for as long as I needed her to be.

Well, except once but that was because my lead wire to the dizzy came unplugged...

So, to ANYONE who might be having problems like this, save yourself some hassel, and buy an electric fuel pump. I will be replacing my cheapie with an Aeromotive unit as soon as I have the money.
 
Long time ago in a land far away, I had a similar problem and sure enough found the same solution...fuel perk from the pump up forward....stuck a electric pusher in back and no more issues.....

sorry I missed this thread some time ago....

:thumbs::twitch:
 
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