Holley HP1000

[pwm72]

I was wondering if I could get a little carburetor help. My car is a 72 Skylark convertible. I have a 1970 455 that has been rebuilt with small valve heads, stock compression ratio, a TA 288-94h cam (234/240), headers, TA SP1, GM HEI ignition with MSD 6AL box. My trans is a SP 400 with a Burek converter and I have a 12 bolt posi with 3.73 gears. Before I switched from the stock intake to the SP1, I was running a tired Qjet that was giving me fits. So, since I figured on eventually getting decent heads, I saw a board member with a Holley HP1000 carb for sale at a decent price. We made a deal and I installed the carb on my new SP1. I made it up to Yardley’s spring picnic, but was having some tuning issues...the carb would bog at just about anything over ¼ throttle. It was fine if you eased into it, but nail it and it would fall over, sometimes backfiring through the carb. My timing is set at 12 initial and 22 mechanical (in by 2000rpm)
So I bought the book “Super Tuning and Modifying Holley Carbs” by Dave Emanuel and figured I could solve this. I started digging into the carb and obviously went the wrong way with the tuning. As it is now, I can even get the car to idle. In fact, it is so freaking rich that you can’t even stand to be out in the garage when I do start it. And when it is started, when you shut it off, it won’t start again, like it is flooded.

My hope is that I can explain the current set up and perhaps get some ideas as to which way to go with the tune. Currently the carb is set up with 78 jets on the primary side with a 4.5hg power valve and a 31 squirter. On the secondary side, I have 84 jets, a blocked power valve and a 36 squirter. I have a billet baseplate and metering blocks too. The metering blocks are set up with 37’s for the idle feed restrictions and my emulsion bleeds are set up the same on both side with 28, 28, 28 and 40 (see picture)
http://i23.photobucket.com/albums/b352/pwm72/Holley%20HP1000%20problems/MeteringBlock-paintresized.jpg

One thing I noticed when trying to tune the carb was that the idle mixture screws had no effect...I could turn them in to seat them and the car would still run, no stumbling or anything. I checked the transfer slots and have them both set to .020. But when setting them, I noticed what appear to be two holes drilled into the baseplate on the secondary side. Are they supposed to be there (Pictures below). They are the holes directly below the text in the pictures.
http://i23.photobucket.com/albums/b352/pwm72/Holley%20HP1000%20problems/Transferslot-secondary1paintresized.jpg

http://i23.photobucket.com/albums/b352/pwm72/Holley%20HP1000%20problems/Transferslot-secondary2paintresize.jpg

All I can think of is that with these seemingly additional holes, I am getting too much air past the throttle blades. Can I compensate for that somehow?

And the final issue, the return spring on the secondary throttle shaft, should this be tight enough to return the throttle blades completely closed? See the video below, the spring doesn’t seem to be tight enough to me. Thoughts?

http://www.youtube.com/watch?v=XtuTPC0UX38

I was really hoping to have the car able to go to Columbus, but that looks about impossible now. But my nephew is getting married in September and would like to use my car from the church to the reception, so I would like to solve this in time for that.

I know that the carb is large, but I have heard a million times on this board that Buicks like big carbs. Help me make mine right PLEASE????!!!

Frustrated in Maryland...

[LARRY70GS]

Paul,
I wish I could help you but I have never worked on or adjusted Holley carbs. Everyone says they are easy to work on and tune, but you have been having trouble since day one with this carb. How about having your Q-jet rebuilt and put that on for now. My Q-jet on the SP1 runs great. If we were closer, I'd lend you one of my carbs just to see.

[pwm72]

Thanks Larry, it is getting frustrating. And yes, they are easy to work on (easy to take apart and parts are available/plentiful) and they are very tunable, but that may be my downfall...there are TOO MANY varibles to get the right combination (at least for me). I mean Main jets, squirters, powervalves, accelerator pumps and cams, emulsion bleeds, high speed and idle air bleeds...I am just not lucky/knowledgeable enough to land on the right combination yet.
Naturally Columbus is not in my future because the car is not running...AGAIN.

Thanks as always for your reply and offer of assistance. I am hoping that maybe after the BPG, some of the holley gurus can chime in and offer some suggestions.

[70 gsconvt]

Hi, I have a 950HP and can say from experience that they are very easy to work on and tune to your taste. Taking the bowls off to change jets is just four screws and if you use the blue gaskets, they can be re-used. You can change the float levels, idle, air mixture, everything very easily.

[LARRY70GS]

Paul,
What about the Q-jet. And who says you have to bring your Buick. Just come anyway. I posted the Specs on my AED carb. Try to match that.


http://www.v8buick.com/attachment.php?attachmentid=87174&d=1169934555

[RG67BEAST]

The carb will run rich untill you get some tunabilty from the idle circut. It controls the idle mixture and part throttle mixture. You must get the idle mixture screws to work. I believe your throttle blades are to far open for the idle circut to work.
The HP carbs have a 4 corner idle circut. All 4 idle mixture screws should be turned the same outward. Try .010" clearance for the pri. & sec. throtlle blades. There is an adjustment for the secondary side too. You gotta get it from underneith. If the cam is wimpy you may have to go to .008". You may have to turn idle mixture screws only 1/2 to 1 turn out but the carbs idle circut will be working.
Adj. the floats until gas just is at the level of the sight hole on the sides of the bowls.
My 950's throtlle blades all have the holes you speak of.
The above should work. If you want more tunability you can get larger air bleeds (the 2 outer on top the carb). This will pull out less fuel and make the idle circuit work.
I have a Holly book around here somewhere if you want to know what jets and squirters were stock.
Once the car is running decent get a power valve for the primaries 2 sizes below the vacuum the engine has at hot idle in gear. You will want one more than 4.5.
Ray

[pwm72]

Paul,
What about the Q-jet. And who says you have to bring your Buick. Just come anyway. I posted the Specs on my AED carb. Try to match that.


http://www.v8buick.com/attachment.php?attachmentid=87174&d=1169934555


I tried your AED specs Larry and frankly it ran so rich it burned my eyes and still could not get it to idle. So I dialed the jets back a bit.

Phil, yeah they are easy to take apart and put back together...and I do have the blue gaskets (thank goodness!), but the trick is getting the combo of parts right which is where my problem lies.

Ray, I tried the idle mixtures screws to lightly seat, then backed them all out 3/4 of a turn...I start the car and try to adjust them and they still have no effect. I just double checked my transfer slot exposure and it is set to .020 on both primary and secondary side. My secondary throttle blades are adjustable the same way the fronts are. I was just curious if those holes were supposed to be there or not, I have heard of people drilling holes in the throttle blades, but not in the baseplate itself before. It just seems odd that they are placed differently...which is what led me to believe that they were just drilled in there. Regarding the powervalve, I have also tried a 6.5 both front and rear and it didn't seem to have any effect either.

[71GS455]

Paul,
How much vacuum do you commonly pull with the motor?
This page has a pretty simple discussion regarding the power valve relative to vacuum along with other Holley tips: http://www.mortec.com/carbtip1.htm

[LARRY70GS]

I tried your AED specs Larry and frankly it ran so rich it burned my eyes and still could not get it to idle. So I dialed the jets back a bit.


Paul,
You have some other type of problem. It is not the jets. The problem is for some reason, you are running on the main system, not the idle system. That is why the idle screws have no effect. I don't know enough about Holleys to even venture a guess.

[RG67BEAST]

Be sure the accelerator pump arms are set at 0 -.005" clearance. They can give a rich mixture at idle if they are missadjusted always giving fuel. You must adjust the idle screw then the readjust the accelerator pump arm for .000 too .005 clearance on the primarmy side. The secondary side pump arm should be the same clearance.
Ray

[pwm72]

Paul,
How much vacuum do you commonly pull with the motor?
This page has a pretty simple discussion regarding the power valve relative to vacuum along with other Holley tips: http://www.mortec.com/carbtip1.htm

I had seen that Steve and other web articles that give different advice...like taking your vacuum measurement and dividing in 2 for a powervalve size. I have 12 ~14 hg of vacuum at idle which is why I have tried some 6.5's.

Could I have an unidentified vacuum leak? Would that cause similar symptoms?
When I am trying to get the car to idle, I can see fuel dripping out of the squirters and when I shut it down, I get smoke out of the carb.

[7 skylark 1]

did you check your float level ?(try lowering the float a little) what is your fuel pressure ?(7 to 7 1/2psi) is fuel dripping out your accelrator pump squirters or your boosters ? if you take it apart check that the metering block sits flat against the main body with no gasket. i once tried billet metering blocks and the power valve was touching the the main body preventing a good seal of the gaskets. the rear was really bad with a power valve plug in it. looking at the pic of your metering block i have a ?. if you put a gasket on the metering block does the hole on top of the gasket for the idle air bleed line up with the idle feed channel in your metering block ? also check the kill bleed(the tiny hole at the top of the emulsion channel) poke a wire through and make sure its clear of any obstructions. some people are have problems with the anodizing restricting the hole.

yes the spring on the secondaries should be strong enough to close by itself.

hope some of this helps.

[sailbrd]

I am just learning about Holly's also but it is pretty obvious that fuel is getting in through some place it is not supposed to. The most interesting thing is that changing the jets changes the idle mixture. This should not be happening. Changing main jets should not effect the idle. Someone can correct me on this but I think that until the idle works correctly nothing else is going to work properly. Do not worry that much about the main jets. Most of us are running 78 to 82 on the primaries and 82's with a power valve on the secondaries or 88 to 90 without a power valve. If it was me I would set it up 80 squared and try and find the leak. That jetting will be close enough to start to look for the other problems.

Eliminate the accelerator pumps for a while. Back those off so they are kind of sloppy. Just make sure they are not effecting the idle.

A Holly should work good with the vacuum you are pulling. It does not take many turns out for my 950HP with all four corners working, I start at one out and work in tiny amounts on each screw.

Did you use real Holly power vavles? I have heard that some others can be real junk brand new. If the power valve is working again it should have no effect on your idle.

I really like the clear float level screws. Let you know right away if you have a problem there.

Just throwing some more ideas out, hope one of them does you some good.

[pwm72]

did you check your float level ?(try lowering the float a little) what is your fuel pressure ?(7 to 7 1/2psi) is fuel dripping out your accelrator pump squirters or your boosters ? if you take it apart check that the metering block sits flat against the main body with no gasket. i once tried billet metering blocks and the power valve was touching the the main body preventing a good seal of the gaskets. the rear was really bad with a power valve plug in it. looking at the pic of your metering block i have a ?. if you put a gasket on the metering block does the hole on top of the gasket for the idle air bleed line up with the idle feed channel in your metering block ? also check the kill bleed(the tiny hole at the top of the emulsion channel) poke a wire through and make sure its clear of any obstructions. some people are have problems with the anodizing restricting the hole.

yes the spring on the secondaries should be strong enough to close by itself.

hope some of this helps.

Hey Dave, thanks for the response, I checked the metering blocks and they do seem to sit flat against the main body. I also did as you suggested and ran some wire in the metering block holes, all seemed ok. I just dry set the floats and will reassemble the carb tomorrow and try mounting it again to see what I get. I will adjust the flaots with the bowls full as well...I have the clear sight windows. Regarding your question about the gasket, all holes/chennels seem to line up fine. I am using the reuseable blue gaskets and all other components that I am useing all holley brand (power valves, jets, etc...).

On that secondary spring, could I adjust it by just winding it one more time? That should provide more than enough spring tension to snap them shut I would assume.

Doug, I will try backing off the adjustment for the accelerator pump arms too. I had them set with no play and with the throttle wide open I made sure that I had .015 before the pump arm would bind. But I will back them off as sugested to eliminate that as a concern.

I really appreciate all the input here...I just have to get this thing running right. It's driving me batty. And Larry, thanks again for the call...best of luck in Ohio!:TU:

[sootie007]

I have that same cam and Jim W. told me to run 15 initial with it which is up from your 12 ....you may want to try that.... My car isnt running yet with that cam BUT I had a pretty stout cammed Chevy 350 in my 32 Ford that had a brand new Holley 750 d.p. on it...like yours when I nailed it or tipped it in quick it felt overcarbed , overloaded , boggy etc....after talking to a knowledgeable racer friend he suggested simply putting another 3-5 degrees intial in and it woke it right up / was like night and day and cured all my carb problems with that combo......J .

[DaWildcat]

You did make sure that power valve's not ruptured (blown), right?

Devon

[buick64203]

Moroso makes a neat power valve tester that you hook to a vacuum pump. One backfire through the carb will take out a power valve.

[pwm72]

You did make sure that power valve's not ruptured (blown), right?

Devon

I thought the HP Series Carbs all had power valve blow out protection, at least that is what it says on Holleys website. And when I did order new powervalves (different sizes) they were Holley branded if that matters.

[7 skylark 1]

if fuel is leaking from the accelerator pump nozzle, remove the nozzle and check to make sure the steel check valve is under it. are the metering block gaskets new ?

[pwm72]

if fuel is leaking from the accelerator pump nozzle, remove the nozzle and check to make sure the steel check valve is under it. are the metering block gaskets new ?

There should be a check ball in the squirter nozzle?

The metering block gaskets/fuel bowl gaskets are not new, they came when I purchased the carb from a board member. But I am ordering new gaskets and needle/seat assemblies tonight. Any advantage to running titanium .150" needle/seat assemblies or should I stick with the standard .110" units?

At this point, just about everything is new on this carb.

[7 skylark 1]

if you look at the cover of your holley book, in the cut away picture of the carb under the front squirter you can see the check valve i'm talking about. if you remove the squirter and look down the hole you can see it, then turn the carb upside down it should fall out. i would stick with the standard .110 neeedle and seats. from what i remember reading they are good to 600hp. when you get it all back together try running manifold vacuum to your vacuum advance, that should help clean up your idle(as long as you don't have fuel dripping out any where). have you traced the holes in the throttle plate to see where they go ?

[pwm72]

if you look at the cover of your holley book, in the cut away picture of the carb under the front squirter you can see the check valve i'm talking about. if you remove the squirter and look down the hole you can see it, then turn the carb upside down it should fall out. i would stick with the standard .110 neeedle and seats. from what i remember reading they are good to 600hp. when you get it all back together try running manifold vacuum to your vacuum advance, that should help clean up your idle(as long as you don't have fuel dripping out any where). have you traced the holes in the throttle plate to see where they go ?
Yeah Dave, I checked it out and there are little "weights" under the squirters (with a tapered end).
Regarding those holes, they were just drilled on the secondary side and I pulled the baseplate off the carb today and ran a wire through them and they terminate in the same well as the transfer slot. So since I have them, should I expose even less of the transfer slot than .020? Apparently the guy I bought this carb from ran a pretty big cam.
Thoughts?

[7 skylark 1]

i would try closing up the secondaries and see what happens. if you go to http://www.innovatemotorsports.com/forums/index.php there is a bunch of people that know more and should be able to help out.. go to the general tunning section.

[SC72Buick]

I thought the HP Series Carbs all had power valve blow out protection, at least that is what it says on Holleys website. And when I did order new powervalves (different sizes) they were Holley branded if that matters.

The actual Holleys do have PV blowout protection, but that is a purple Pro Form baseplate:grin:

[SC72Buick]

Hey Paul,
Give me a call at Holley Tech 866-464-6553 and ask for Mike. We are open 8:00-5:00 CST (Mon-Fri). I can give you all the original Holley bleed sizes for the 1000HP. It is hard to say what is up with the ProForm blocks and baseplate you have. I would definately replace the metering block and fuel bowl gaskets. These are good for maybe 3-4 times on and off with the block then they need to be replaced to make sure they seal. Lets get the carb set all back up to factory Holley specs and start from scratch. What is the List number on the side of the main body????

Thanks, Mike

[pwm72]

Hey Paul,
Give me a call at Holley Tech 866-464-6553 and ask for Mike. We are open 8:00-5:00 CST (Mon-Fri). I can give you all the original Holley bleed sizes for the 1000HP. It is hard to say what is up with the ProForm blocks and baseplate you have. I would definately replace the metering block and fuel bowl gaskets. These are good for maybe 3-4 times on and off with the block then they need to be replaced to make sure they seal. Lets get the carb set all back up to factory Holley specs and start from scratch. What is the List number on the side of the main body????

Thanks, Mike
Hey Mike, sorry been traveling all week for work, just getting back on the boards now. I will try calling next week if you don't mind unless I can call this weekend. I actually sent a message to Holley Tech assistance a few months ago with no response (thru the holley website). I would love to set the carb back up to out of the box and take it from there.
The carb number is LIST 80514 HP Series and it is the annular booster model. Under that is shows 1908. On the top of the air horn is has 6R-7880 B.
Any info would be GREATLY appreciated.
Thanks much!

[pwm72]

Thought I would provide a little update on my issue. I had been speaking to Mike Kise from this board (he works at Holley) and he has helped tremendously...even sent me a new baseplate.

Anyway, I totally went through the entire carb and replaced all that I could so that I knew what I was working with. New gaskets, needle and seats, jets, powervalves, pump diaphragms, shooters, shooter screws, you name it.

With info from Mike (thanks again!) I sent it up as close to back to "out of the box" as I could. I am happy to report that the car starts, idles and drives. The idle mixture screws even work as they should now.

I had the car out on the weekend and there was an off idle stumble. So reading my holley book it suggests going up a shooter size. So my current combo is now:
84 jets Primary
88 jets Secondary
6.5 power valves front and rear
32 squirter primary
36 squirter secondary
Pink pump cam in the front and the brown cam on the 50cc pump in the rear.

My ignition is GM HEI w/ MSD 6AL, 14* initial with 20* mechanical all in my 2500rpm. No vacuum advance.

I have a TA 288/94 cam and have a steady 10hg of vacuum at idle in gear.
I just changed the plugs (running AC r43TS)

I had the car back out tonight after switching the front squirter and it seems to have helped the stumble a little, but I noticed that the stumble becomes much more pronounced as the car warms up. I was driving for about 10 minutes and every stop sign or light, I could not pull away cleanly. Once above about 2000rpm, watch out...but below that, I had a serious stumble. It does not seem to be popping back through the carb though as it was in the past.

Any idea what would cause the stumble to get worse as the car heats up under load?

[70aqua_custom]

no idea. It should need more fuel when it's cold. :Do No: but if it was me I'd increase the pump shot some more. I went through this with a Holley 750 DP and when I got it right she would smoke the tires instead of popping out of the carb.

[sailbrd]

Paul,
From what I see your problem is not the carb. (unless the carb is total FUBAR)
As far as I can tell no one is running that much fuel into what is a fairly mild motor. The biggest jets I ever ran with the 950 QuickFuel was 85's with power valves and that was very rich. Many setups are going with around 90 on the secondaries with no power valve. This is on motors with more cam, heads and compression than you have. The cam you are running should pull more than 10 inches of vacuum.

What do your plugs look like. If they are not brown (I think they should be black) then you need to look for something else. The only thing that makes sense to me is a big vacuum leak. If you have white or light colored plugs it has to be a leak.

Wish you were close enough to just bolt on my carb but no such luck.

Check to see if the carb pad on the manifold is flat.

Be careful with this one, spray either at the base of the carb and see if the idle jumps. If nothing there try this where the manifold and heads meet.

Crank the initial up to 20 degrees and see if the stumble goes away, will not hurt anything in low gear just testing for throttle response.

Post pics of the plugs you took out.

[LARRY70GS]

Paul,
I agree with Doug, you have a vacuum leak somewhere, maybe in the valley. Your SP1 may not fit right. You should have at least 13-14" of vacuum. My cam is 228/246, 118 LSA and I have 16" in gear at a 750 RPM idle.

[7 skylark 1]

i would try more initial timing. also try a blue or green pump cam on the primary. i run the 113 cam and have 13" vacuum. the more initial timing i give it the better it gets. i just locked out the advance and so far i am very happy with it.

[pwm72]

Thanks as always for the suggestions guys. I tried the ether trick (Starting fluid...right?) last night and did not detect any change in idle. I tried around the base of the carb and along where the heads/intake mate.

Stupid question for you though...on those of you running a big holley on an SP1, what are you doing to plug the PCV hole in the rear of the intake? Does your Holley have a vacuum port on the baseplate for the PCV? I have one baseplate (billet aftermarket) that has the vacuum port and one (stock Holley) that does not have the vacuum port.

Doug, I can post pics of the plugs that I have taken out, but I am not sure they will hold much of a key...they are really pretty black, but if you go back to my first post, the car was running so rich that you could not stand in the garage. I have not run the car much since I got the carb set properly and it has only been with the new plugs...and they appear white. I can post pics, but it is only after about 10 mins running time. Not sure if that has any value or not.

[pwm72]

Fow what it's worth, here are two pics of a spark plug with about 20 minutes run time on them...Took it out again today and I "think" I can hear a whistle when I boot into it. So I think the vacuum leak may be the issue. Would it whistle?
I pulled a few plugs and they all looked the same.

http://i23.photobucket.com/albums/b352/pwm72/P1010188.jpg

http://i23.photobucket.com/albums/b352/pwm72/P1010187.jpg

Thoughts?

[LARRY70GS]

Would it whistle?



Yes it would, find out where the whistle is coming from and you'll find the leak. Leave the vacuum gauge connected to the running engine. It will climb when you get near the leak with light oil or whatever you're spraying.

[sailbrd]

Paul,
I can't get anything from the plugs either. I am finding out that plug reading is so much different now with unleaded fuel that it is a waste of time. I just spent all day driving my car with an O2 sensor. The plugs are looking "good" and I am running 11 to 12 on the air fuel ratio. Way rich. Put it on the dyno and pulled some interesting numbers and learned a lot. Will share in a separate thread.

On thing I am now sure of. There is no way you can use the size jets you are trying. I was running 82 primary and 84 secondary and you see the numbers.

Now the pcv hole is where the pcv valve goes. It has a rubber grommet pcv valve goes in and connects to a big inlet at the base of the carb. I was going to ask you if you had checked the pcv valve. Those things can cause all sorts of problems. I think the next thing to try is block off every vacuum source, power brakes, distrubutor, pcv, etc. See if that brings the vacuum up. If it does we are making progress. Let us know. I really want this thing to work for you.

[DaWildcat]

Fow what it's worth, here are two pics of a spark plug with about 20 minutes run time on them...Took it out again today and I "think" I can hear a whistle when I boot into it. So I think the vacuum leak may be the issue. Would it whistle?
I pulled a few plugs and they all looked the same.

http://i23.photobucket.com/albums/b352/pwm72/P1010188.jpg

http://i23.photobucket.com/albums/b352/pwm72/P1010187.jpg

Thoughts?


Reading plugs with today's gasoline is much less fruitful than yesteryear.

The key to reading a plug is to know how it was behaving at W.O.T., and you can't see this by looking at a set after some driving around time. The trick to getting a good reading is to hit it hard, wide open throttle...then immediate shutdown so that part-throttle mixtures don't screw up the color. This might give you more insight.

Devon