Alrighty, here we go again...

My '66 V100 with '72 block and peanut plug head, M-1 aluminum 2bbl intake, and BBD atop it, runs rough below around 1500 RPM, and it sounds like I shut the ignition off if I let it drop below that. Lightly pumping the throttle will make it run, and if I press it a bit further then release, the RPMS zoom up, and then back down... so I have a vacuum leak somewhere.

I am wondering if I have the correct gasket. It has 2 cutouts on the outward edge of each bore, so it seems to be right right one. Are there any additional holes that are supposed to be on that gasket? I get vacuum to the PCV, and to the choke diaphragm.

Doesn't matter where timing is set, doesn't matter where idle mix screws are, all that matters is how fast the engine is spinning. It has a BBD that was "Rebuilt by Holley", and the BBD that came with the car. Both act the same.

In case I cannot find any vacuum leaks (headed out to buy more carb cleaner now) what would be another good thing to check. The damper has slipped, so a timing light won't help. I estimate that it is around 10 BTDC.

Throttle response is quick, and it runs well under load when the throttle is open far enough, but it absoutely dies when I take my foot off of it. I am not losing spark, because if I am rolling and I take my foot off, then press back on, the engine picks up again.

I have already sealed the EGR valve by turning it around and coating the gasket with a light layer of high temp (orange) RTV.

Any other thoughts?

I have read this,this, and this which had similar symptoms, but I couldn't draw many conclusions.

~THOR~

_________________
1984 D100 Shorty Custom
Certified Auto Appraiser - RevItUp Classic Appraisals
President - Cherry City Bombers CC
Part of Tyrde-Browne Racing

Thor, I know you’ve already checked for that crack in the intake under the carburetor that someone was talking about aluminum intakes being prone to acquire the other day...

Danny

If you find it's cracked, I have a couple buddies that can TIG it. If it's on a machine surface, we can work up a setup and fly cut or mill it on my milling machine. It wouldn't be the first time a Super-Six was locked to my cross-slide..

CJ

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Part of Tyrde-Browne Racing

Thanks Danny for that... I will take a look tomorrow.

If it is cracked, I will pull the iron one from the trunk and install it.... then I will have it welded later... I want to drive this car now!

Now... how do I remove the broken part of a key from the trunk lock, and then get a new key for it?



~THOR~

_________________
1984 D100 Shorty Custom
Certified Auto Appraiser - RevItUp Classic Appraisals
President - Cherry City Bombers CC
Part of Tyrde-Browne Racing

Pull the tumbler from the trunk, take it to a lock smith, and have him fix it.

I have a pretty good Locksmith in Corvallis, and another in Albany that made me keys within minutes of doing magic to a tumbler that we couldn't remove. I like going to the guy in Corvallis 'cause we were ER's of our respective Lodges the same year. Partying together at Grand Lodge has an effect...

You know how to open a trunk from inside the car. I'd never have thought you could fit past that drum set, but you proved me wrong!

CJ

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Part of Tyrde-Browne Racing

It may be a little more difficult getting through the backseat of this car... it's smaller, but there is far less junk in the way!!

I can fit into spaces no one thought possible... not sure if that's a good thing or not...

~THOR~

_________________
1984 D100 Shorty Custom
Certified Auto Appraiser - RevItUp Classic Appraisals
President - Cherry City Bombers CC
Part of Tyrde-Browne Racing

I should also make mention that when I got the car Sunday, it had a really high idle... can't imagine why! If the P.O. had it up that far (where it will run w/o use of an organic throttle actuator) because no one could figure out what was wrong with it, then I would not be surprised to find the crack that was mentioned.

The wierd thing is that I idled it down to an acceptable (around 1000) level, and the car ran great until I was on my way home from a friends house, and it was starting to idle rough...

Hmmmm.....


~THOR~

_________________
1984 D100 Shorty Custom
Certified Auto Appraiser - RevItUp Classic Appraisals
President - Cherry City Bombers CC
Part of Tyrde-Browne Racing

Cracks get bigger as they get hotter.

Purchased in Monroe Or, drove to gas station in Junction City (30min @ 55 mph) ran fine. Filled with fuel. Drove from Junction city to Halsey (20 min @ ~55mph), ran fine. Cooled off, drove from Halsey to North Salem (50 min @ 65mph), ran fine. Drive from north to south Salem (10 min, city driving), ran fine, then it sat for a few minutes. I gave some friends a quick ride, which is when it was barely beginning to idle weird.

Drove home to North from South, and it was noticeable that something was not quite right. Got up this morning... will not idle.

I suppose it's not outlandish by any means to think that it may have taken that much time to crack.... I am not experienced with aluminum in that regard, so it could very possibly be.

In fact, I hope it is, because then I can swap manifolds, and be back to driving it!

~THOR~

_________________
1984 D100 Shorty Custom
Certified Auto Appraiser - RevItUp Classic Appraisals
President - Cherry City Bombers CC
Part of Tyrde-Browne Racing

No, that sounds like too long for it to wait. It's either something else (most likely is) or someone had a bandaid on something that fell off.

Danny

Hey Thor
That sounds like trash in the carb. Maybe from the gas lines or tank (varnish) broke loose. I would add a clear fuel filter in line with the one that allready there(there is one there right?) and run something to flush the varnish out.
Frank

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Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered

It already has a clear filter, and the filter is clean... I have tried a different (clean) carb, and it did the same thing... I bought 2 cans of carb cleaner, and I will go looking for trouble when I get home...

~THOR~

_________________
1984 D100 Shorty Custom
Certified Auto Appraiser - RevItUp Classic Appraisals
President - Cherry City Bombers CC
Part of Tyrde-Browne Racing

Ok get this.... no cracks in the manifold that I can see, and no vacuum leaks either...

I took carb cleaner and sprayed both sides of every intake runner where it meets the head (except between 3 & 4 because it's solid) no change. I sprayed the carb base, no change. I sprayed the carb gaskets and vacuum lines, no change. I sprayed all around the EGR (which has been turned around) no change. I sprayed the throttle shaft on both ends, no change. I sprayed the vacuum tree, no change. I sprayed into the carb bore... it changed... so at least I know that if there was a leak that is causing that much of an issue, it would have changed.

If I try choking it, the engine dies. If I let the throttle go, the engine dies.

If I try cranking without stepping on the gas, it won't even puff.

I am absolutely stumped. It runs well at higher RPMS, so I am most likely just going to tear the carb down and see what's up, see if the idle ports are clogged or something. It has the clear filter as mentioned earlier, and I havent seen any junk in it...

It is completely indicative of a clogged idle circuit, but I also need to make sure I have the correct gasket for the carb, if it's not allowing vacuum somewhere, then maybe thats it.. like I said, I am stumped..

I am going to go pull plugs...

~THOR~

_________________
1984 D100 Shorty Custom
Certified Auto Appraiser - RevItUp Classic Appraisals
President - Cherry City Bombers CC
Part of Tyrde-Browne Racing

did you set your floats properly?

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-- Mister Perkins --

Pictures of my truck
http://www.cardomain.com/ride/3257131p

Is the valve lash correct? Have you checked the timing chain to make sure it's not off... the timing chain could get sloppy when warm and give you grief, but be tighter when cold...

Just a thought.

-D.Idiot