Holley Issues Continue......

[CoggedBelt75]

I agree with Andy on fixing something online. Don’t know what all has been done. Especially since it’s used. If taken apart, a gasket could’ve been turned wrong (yep, I’ve done this), blocking passageways that are suppose to be open. In your case, if no fuel is making it to the back bowl, it’s either float is sticking causing the needle and seat to close, or the needle itself is stuck closed. Of course this will not let the fuel enter the bowl. Mine usually stick open occasionally and all it usually takes is a few light hammer taps on the adjustment screw and nut. Might try that to see what happens. Still no fuel, pull it out and clean it with carb cleaner and reset float. To me, that’s all that controls the fuel entering the bowls.

 

[Doppleganger]

I did get the bowls to fill -their level is just below the window.....if I shake the truck it dribbles out. I think what I need to check (among many other things) is the accelerator pump and the fuel / volume. The original quadrajet I had rebuilt. Guy told me the bowls were full of dirt - to change or clean my tanks. I have new tanks (w/baffles) for a TBI swap. What I'm wondering if there is debris that is in the fuel line and restricting it that way. Also have to find where the filter is (if there even is one the way Capt Cobbler did this thing) and change it too. Heck, it could be plugged.

I have 2 new mechanical pumps - got a great deal last year so bagged 2 of them. Will probably swap it out anyways as I dont know what brand or where the one on it came from (can tell it was replaced), as well as the line from the pump to the carb.

I just needed it to get by this year so I can literally gut the truck to a shell and start over next year. No shop large enough to do it in so gotta be in the mild months. It has never been solid-reliable since I got it so no doubt there's alot to find and redo. I restore older Euro cars (not by choice - lol) - have my last one just back from paint yesterday and another almost done that HAVE to be done and gone this year, so not alot of time to keep messing with this truck. I'm used to the atypical previously owned vehicles and how cobbed or butchered they usually are. I love the truck but for time's sake wish I had never gotten it at this point.

Just amazes me that no shops even know how to do any of this anymore.

 

[bucket]

One thing you can try is removing the fuel line that feeds the pump, then blowing compressed air into it. Just a small amount of air, you don't want to really blast it. If anything is lodged in there, it may come loose. If it runs better after that, you know you need to take the lines out and clean/replace.

 

[Doppleganger]

One thing you can try is removing the fuel line that feeds the pump, then blowing compressed air into it. Just a small amount of air, you don't want to really blast it. If anything is lodged in there, it may come loose. If it runs better after that, you know you need to take the lines out and clean/replace.

Does it go back to the tank-switch solenoid? When the pump is off would be a good time to do that.

 

[Doppleganger]

Messed with it some this AM before planet Ohio drifted to a mile from the sun. Has great spark - timing is on the money. Has a newer distributor - has zero wear (inside of cap is clean as a bell too). Plugs are new.....they replaced the ORIGINALS (no sht) about 10 days ago.

The accelerator pump works fine but the cam that makes it work is too small IMO and doesn't push it down enough.

The pump the PO replaced is getting deep-6'd. Have a new one to go on. The fuel lines are all in excellent shape - this truck was a lifetime Oregon truck and has zero rust underneath. However, the short rubber lines that go from the hard lines to the pump look very original and very tired......like me! So going to replace those while its out too.

See what that does if anything.

 

[Brian Lynch]

Have you tried capping the 2 open vacuum ports on the front side, under the primary bowl?

 

[MikeB]

Odd that both carbs have similar issues. May be a vacuum leak or fuel starvation problem. Certainly not a Holley design issue. The carb in the picture looks like a #80457 which works pretty well on an engine like yours. I have the SA (aluminum version), and it's served me well for 4-5 years now. I did have to adjust the floats, and of course the choke and fast idle.

Are you sure the carb is sealed to the spacer, and the spacer to the manifold? Those are common places for leaks.

Is the vacuum advance canister OK, or does it leak? Check by sucking on the hose connected to it. Same for the brake booster.

Speaking of hoses, make sure there are no slits in any of them.

Finally, check ignition advance at idle, and then make sure it increases as RPMs increase.

All that said, you could have a fuel delivery problem. A pressure gage would come in handy. I'd be looking for 4"- 6"

 

[Doppleganger]

Got tired of messing with it so I took it to a shop I knew that would know carbs. 4th gen mechanics in a shop opened in 1928. They had 4 cars in the shop, 3 of which were a 68 Buick, 74 Caddie and a 72 Torino. Everything is set fine - timing, acc pump, etc. Truck starts and runs great but you still have to ease into it at stop lights or it will fall on its face. Idle is also still high and adjusted as low as it will go. I could spray carb cleaner on the back of the carb and get a very very slight reaction in the idle.

They messed with it today and said the vac port on the Holley is not metered - so its at full advance all the time. I marked in the pic the only 2 places it could go. Holley per their pics, says the upper side is where the vac adv goes. Thats where I have it (lower is capped too btw). Is it -possible- this aftermarket unknown distributor could be an issue? I would have gutted this thing the moment it showed up but figured I could get ONE summer of use out of it. I'd like to drop it on the PO's head.

Guy said easiest fix is to put the Q-Jet and OE air cleaner back on and hook up all the vac lines as they were / should be. That would make it fine til I decided what to do with it. I dont have the time to mess with it anymore. If I had $ it'd be FI'd or in someone else's driveway by now.

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[CoggedBelt75]

Thought I would pick this apart a bit. Even tho people are quick to blame the carb, no matter what the brand, more often than not, it is other issues. The main culprit is usually with the timing. Of course we know this is a used carb that apparently set for awhile with fuel left in it and most likely uncovered by the crud in it. Something as simple as changing plug wires can creat issues. Yeah, more times than I want to admit, I am guilty of crossing a wire thru the years. One thing I didn’t mention in the break down is how far out the idle adjustment screw looks on the passenger side. May be an illusion. Would like to see you get this figured out. Carbs are really very simple if you think about it. Far from a carb guru, but I’ve messed with them for many years and could figure things out eventually. Just hard to do long distance without knowing the full story, standing next to it while listening, and feeling it while driving. Hard enough typing all this with two fingers

Got tired of messing with it so I took it to a shop. Everything is set fine - timing, acc pump, etc.

After all the messing with the carb, they set everything back to Holley specs? They set the idle mixture screws using a vacuum gauge? Verified floats were set correctly. What is the timing set at?

Truck starts and runs great but you still have to ease into it at stop lights or it will fall on its face.

Most always a misadjusted accelerator pump arm. But they say it’s alright? Right? Then a vacuum leak somewhere. Hoses may “look” good, but never assume they are.

Idle is also still high and adjusted as low as it will go. I could spray carb cleaner on the back of the carb and get a very very slight reaction in the idle.

Pretty says you have a vacuum leak if spraying raises idle. That’s would be why the idle won’t adjust down. Or timing is set too high.

They messed with it today and said the vac port on the Holley is not metered - so its at full advance all the time.

Not sure they’re saying here. Anything above the throttle plate is ported vacuum (only pulls vacuum once the blades start opening up). Usually used on smog checked engines. Anything under the plate is manifold vacuum (pulls all the time). Full time usually is best for improved idle.

I marked in the pic the only 2 places it could go. Holley per their pics, says the upper side is where the vac adv goes.

Probably one of the most heated debates on the web. Some claim top port on block is the best. Some the lower port. No 2 engines are the same so different strokes for different folks. Try both while idling. I’m thinking the lower will give the best idle.

 

[Doppleganger]

Thanks for the input Joe. I'm bewildered with the ongoing saga this has become. Mechanic said the port that I had it on was not metered.....could it be malfunctioning or another issue with the carb? Said I had full advance all the time and that was why it was falling on its face under load. I can try it on the other port and run it around the block. IIRC it was there before and ran the same - played musical ports so much I dont remember for sure.

Another thing I wonder about is the aftermarket ?-brand distributor. Am wondering could the vac adv issue on that end.

Timing is at 10 adv. Mechanic said he checked the acc pump and it was working and set good. I told him of the possible leak in the back but he never said anything about it. When it stumbles, it wants to almost back fire - thus a reason I thought it was still a timing issue.

I dont want to keep harping on this issue. The truck is stupid clean - zero rust and an overall pretty straight bod. 100k one owner miles. Its issues began when the PO's cerebralplegic son started 'fixing' things. The ignition lock broke so he put a JY column in....and in doing so killed every gauge except the speedo and oil press. The QJet was fine but he decided to swap it with a (used) Holley 390 (said it was a 650) - too little carb for the motor. I have heard of guys really fudging the timing to make up for under-carburation and think this is why it was so far off the mark when I got it. Thank God he left the QJet in a box in the bed as I had it rebuilt....fella who did it said it wasn't in bad shape to begin with. In doing so he removed literally 95% of the vac lines under the hood. Only ones left were the booster and breather. He also pulled the distributor - again, no idea why - and tossed the original. Wiring, etc is cut/taped off everywhere. Heater core was bypassed. Best part - he put in new plug wires with........the original plugs. I pulled the circa 1985 plugs with 100k out and changed them. UFB

So this is a truck I see zero chance of taping things back together - it will be gutted to a shell and a start over...if I have $ to keep it after all this. I was just hoping to be able to use it for needed local hauling (lumber, siding, etc I needed to do this summer) until going full rebuild with it. I always thought I was ahead due to no bodywork (paint only) being needed.....but I'm starting to wonder that now too.

 

[CoggedBelt75]

But again, when you spray around the carb and the idle is affected, there is definitely a leak somewhere. Even reusing the base plate gaskets can cause a leak. Especially if they are turned differently than they were when taken off. The impressions on the bottom of the plate won’t match up with the ones left on the gasket. Something so simple as this can create an issue. Just a thought. You have to find and eliminate the leak first.

 

[Frankenchevy]

I’ll admit I didn’t read through the whole thread.

What Joe is saying is correct. If your getting rpm increases by spraying around the intake/carb you have a vacuum leak and no adjustments will be correct. I’d start simple and cheap. New vacuum hoses, new vacuum caps wherever applicable, new carb gasket and maybe even intake gasket if you’re still finding a vacuum leak after the easier stuff. If you have a carb spacer, you’ll need two base gaskets.

I apologize if any of this is repeat advice or something you already knew. I chased a vacuum leak for a couple hours only to find a new (few months old) vacuum nipple on the carb had already developed an almost invisible crack.

You can have vacuum leaks in your brake booster too. Not sure if that’s been covered either.

 

[CoggedBelt75]

Them port caps they make are cheap junk. Mainly the rubber ones. They appear fine just looking at them. But pull one off and usually there will be a crack. Found 2 on mine that failed within a short amount of time. The plastic type caps seem to hold up better.

 

[Doppleganger]

I thought of pulling the Holley and the base plate and starting over there - considering everything else, might just be dirt under it. If its an intake gasket it will sit as it is til a new motor (or owner) next year - no time for that at the moment. I know the Q-Jet has more vac ports than the Holley - enough to put things back to how they came. It also eliminates the base plate and has all new gaskets to boot, so will probably go that route.

Wish I never bought this thing. If I could get out of it anywhere close to what I have in it, it would be gone now.

Thanks a bunch fellas.

 

[Backfoot100]

Mechanic said the port that I had it on was not metered.....could it be malfunctioning or another issue with the carb? Said I had full advance all the time and that was why it was falling on its face under load.

Timing is at 10 adv. Mechanic said he checked the acc pump and it was working and set good. I told him of the possible leak in the back but he never said anything about it. When it stumbles, it wants to almost back fire - thus a reason I thought it was still a timing issue.

Well thats just ********. Having the vacuum advance on manifold vacuum does have it advanced as far as it goes. Thats true. However when you stab the throttle your vacuum drops to zero which essentially disables the vacuum advance. The mechanical advance does the timing advance then until you let off the throttle. At some point both the vacuum and mechanical advance work together.
With a timing light on it can you see the timing advance when you wick the throttle? Does the rotor assembly advance several degrees feely with the cap off? Does the mechanical advance weights move freely without sticking?
Without knowing for sure what distributor you have and what advance curve is built into it you could very well experience this.

I have to assume its doing something because you admitted that with the other carb you could at least ease into it slowly to be drivable.

Agree with others that there could very well be a vacuum leak someplace. If this thing is butchered like you say there could very well be a problem.

Maybe not much help but maybe something will jump out at you.