IHADAV8.com - Turbo Buick Tech, and Nonsense
Tech Area => General Auto Tech => Topic started by: Scoobum on April 30 2017, 08:05:11 AM
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Gonna have him source a new regulator. Joe's a Mopar guy, so I may be able to get one out of Montreal.
Next up. The car shuts off as soon as you let your foot out of it from a WOT blast. The carb was setup in Florida...in hot humid weather.
Low 40's here. I'll assume it's not getting enuf fuel at idle? Readjust the idle mix screws...and retry? Where do I source vacuum from to set them?
The 'sight' glass on the two bowls shows fuel at the half...right between the top and bottom of the 'sight' glass. Correct setting?
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Stick a wideband on it Brad!
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Stick a wideband on it Brad!
If it was MY car I definitely would.
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Brad consider the float level. May be set a bit on the low side and has nothing left after a wide open blast
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Brad consider the float level. May be set a bit on the low side and has nothing left after a wide open blast
I campaigned a 77 Nova at Cayuga when I was in my late teens to early 20's. I haven't really messed with carbs since then. I'd set the float levels and mixture screws...then make a pass and check the plugs. Never had an issue with a carb going lean when closing the throttle blades quick. The idle 'hunts' on this car...which makes me thinks it's lean at idle. Get on the gas...and it pulls hard.
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Vacuum guage? or exactly what is the carb and who played with it??
Iwould think if there was a vacuum leak and somebody tried to tune around it could cause that issue.
a bg or demon?
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Brad, I forgot what carb is on it. Is it a Holley style double pumper?
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Brad, I forgot what carb is on it. Is it a Holley style double pumper?
Yeah...checked the vid and it's a 950 Quickfuel.
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Apparently that problem is not unheard of with that carb. speed talk and yb both have questions on it.
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Brad, start with the basics. Make sure the fuel levels are in the middle of the sight glass and not higher. Also check the primary throttle blades and see if they are adjusted correctly so that a slight amount of of the transfer slot is showing as it should be. As you probably know, it is very common to open the primary blades too much which can cause problems because the carb does not switch back to the idle circuits.
Also be sure the fuel pressure is holding thru the run.
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Thanks Steve. Will check with him if he has an in car fuel pressure gauge this week. Ball park figure what the fuel pressure should be? You can see an AFPR under the hood in the vid...so I can adjust it if need be.
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6-7 psi. Not more than 7
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I know you're asking Steve, my 2 cents. Sight glass aside, if the float level is too high, look down the throat of the carb at idle and make sure there isn't any fuel dripping from the nozzles. The vacuum source you want has to be below the throttle shaft, manifold vacuum. Turn the idle screw in one side at a time, starting on the throttle cable side, as soon as you start losing vacuum, stop. Turn out 1/4 turn. Adjust idle speed again and repeat on the other side. Standard for all carbs, timing must be set 1st tho. Sorry if I'm repeating stuff you already know.
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I know you're asking Steve, my 2 cents. Sight glass aside, if the float level is too high, look down the throat of the carb at idle and make sure there isn't any fuel dripping from the nozzles. The vacuum source you want has to be below the throttle shaft, manifold vacuum. Turn the idle screw in one side at a time, starting on the throttle cable side, as soon as you start losing vacuum, stop. Turn out 1/4 turn. Adjust idle speed again and repeat on the other side. Standard for all carbs, timing must be set 1st tho. Sorry if I'm repeating stuff you already know.
Carb appears to be brand new...Quickfue l 950. The car is a weapon...and looks to be built professionally ...or by someone that knows their shit. He has a new regulator on the way from Summit...so that SHOULD...finge rs crossed...keep the voltage up to 14...and keep the battery charged. If he gets the car to the track Friday nite...then we'll see what happens when he lets his foot out of it...and if it pulls the same shit again. If it does, I'm bringing along my vacuum gauge and will adjust the carb. If I'm busy with races, then I'll get my buddy Steve with the turbo'd Hayabusa to handle it. He's a licensed mechanic...and prolly still handles this stuff on a regular basis.
Question. I think Holley...or someone...sell s an EFI 'carb'. Could it handle this engine? It's a 440 stroked to 492...and has run a best of 10.5 at 128.
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Fast, FITech, Holley, Edelbrock, MSD, etc. all make throttlebody set ups. Some of these are better known for support than others.
On a car like this, I would probably not choose a throttle body set up because I think Port injection will come closest to extracting power from it close to a good carb and provide better drivability.
When you go FI, you better be prepared to learn to tune for best performance, or be prepared to pay some one to do it for you. yes, they all self learn but to get serious power across the band, I think you need to fill in the tables and smooth the holes out...
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Thanks Steve. Will do some research on it. Will post up when the regulator arrives. Hopefully it solves the voltage issue...and then deal with the carb. One disaster at a time.
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be sure he has a fuel pressure regulator on the car and set to 6 psi as I suggested
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be sure he has a fuel pressure regulator on the car and set to 6 psi as I suggested
I went back and checked the video and the AFPR is under the hood...purple in color...if that helps in identifying the brand. The fuel pressure gauge is in car. I'll set it to 6 if it isn't at that. Regulator is suppose to arrive Friday from Summit. It's shod with M and H 275/60/15 DR's. Any direction for pressure to run 'em at?
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no...I would say google is your friend as well as anyone at the track running them.
If I guessed, I might start at 16
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16 cold should be a good start. I'd expect 18-20 hot to work just fine. Set them @ 30psi before you two duke it out!
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Thanks guys...we'll try 16. Dan blew his back out. I may get the call. If that's the case, I'll ease it off the line...and lay into the whore.
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Was informed fuel pressure is at 3. Weather is nice...gonna call him to remind him to adjust to 6-7. Busy renovating my kitchen...and he lives 45 minutes away.
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assuming the guage is right, that is low. good luck on the kitchen
On a QF carb, the fuel level should be the middle of the window and not at the bottom of the hole like a Holley
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Texted him today. He's adjusting the fuel pressure Tuesday and installing the new regulator. We'll try it at Armdrop Saturday. Finishing up the baseboarding. Had a young lad install the ceramic floor. New shingles being installed in the next couple weeks. It's a 1 and half story house...pitch is insane. Having a kid do it. I ain't gettin' up there.
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New regulator is holding the voltage at 13...depending on how accurate the gauge is. One of the Mopar guys is bringing a known good fuel pressure gauge to set the fuel pressure at Armdrop on Saturday.
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Voltage should higher than that
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I agree Steve. I'm wondering how accurate the in car voltmeter is. Will check it from the back of the alternator tomorrow. This is Kevin Pelletiers car. He's a Mopar guy through and through. I got Dan to contact him via FB...and we'll meet up with him at Armdrop tomorrow. Kevin's gonna set the fuel pressure and set the carb up. There's an older gent that's a carb wizard...and he'll be there tomorrow as well. I'll report back tomorrow nite on how things went.
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nothing beats on hand experience!
Checking the voltage at the alternator vs another point is very useful. These old alternators are pretty crude in my opinion. They use a double field hook up to measure voltage drop and then try to correct for voltage loss. Usually that creates a high voltage instead of a low. It may be that the alternator itself is bad...and as we know, low voltage can cause an electric fuel pump to pump less than it should.
Some use a modern Denso alternator but you have to get the bracket right and in some positions, the post is almost touching the head.
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Got a text from Dan saying the volts are 14...but drop to 13 when he kicks the fan(s) on. He has a manual switch. Those fan(s) must be drawing a crapload of amps. 12 to 1 compression... engine tightens when it warms up...starter close to the headers. After a run, that battery would have to be at its peak to crank that thing over. That alternator must be working like a whore to keep up with the demand when those fan(s) are on.
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That alternator is probably only 39 amps.you know your next project
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Two guys opened a shop here in town...and all they do is rebuild starters and alternators. If it was my car, I'd have them upgrade the current alternator...o r build a killer one. I'll mention it to him today.
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I would be sure to switch the fans off at the line so the ignition, fuel pump have power
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We hooked up with Kevin. He came over to my trailer...look ed at my roll around tool cabinet...upri ght compressor and generator...an d I started handing him tools. The electric sender unit for the fuel pressure gauge was removed, cleaned and reinstalled. No change...the fuel pressure kept bouncing between 3 and 6. Because this car sat in storage, the consensus is the fuel filter could be partially clogged. He says some have a reusable element...and others are disposable. He took the car for a quick spin down an open runway...and when leaning into it...the fuel pressure started dropping off. If the fuel filter replacement doesn't work...then the pump may have gone south. He's also gonna try a mechanical fuel pressure gauge.
Kevin also adjusted the idle mixture screws. I saw him adjusting the one by ear. I walked over and handed him a vacuum gauge. Looks at me and says, 'You got one of those!?' I started laughing.
Timing was checked...and was to his liking. It has a solid cam...and a couple of rockers have a slight tick...needs adjustment. Plugs were pulled...and were black...and the gaps were a tad wide.
Dan's dropping by Kevins on Monday...and he's gonna go over the entire fuel system.
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Electric or mechanical pump?
Electric will have problems if the fan is on, I would guess. Mechanical pumps often have problems with the pushrod wearing out and bring too short.
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It's electric. It's the trunk mounted one in the vid. Not sure which brand. It was bouncing with the fan either on or off.
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Most electric pumps need to be mounted with the inlet level with the bottom of the tank
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I'll have to go back and check the vid.
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Steve...here's the vid. Fuel setup is at the beginning...ju st pause the vid and have a look.
https://www.youtube.com/watch?v=1BwiPoRlpxo&list=UUx5FoeyV2MovRUIlqWOdBag&index=10 (https://www.youtube.com/watch?v=1BwiPoRlpxo&list=UUx5FoeyV2MovRUIlqWOdBag&index=10)
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It looks good to me. Looks like a canister filter.
Is the cell vented?
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It looks good to me. Looks like a canister filter.
Is the cell vented?
That's a good question. I'll get Dan to get Kevin to check for that.
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Steve...the tank IS vented. Got a text from Dan confirming it.
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sounds like a clogged filter which would be surprising given it is coming out of a fuel cell, weak pump, or plugged line, then.
Be sure that pump is getting 14v at the pump.....
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Will do...thanks.
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Also, be sure the fuel line is insulated from heat under hood so the headers don't cook the fuel in the line on the way to the carb
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Just got a pic on my cell. Here's what's wrong. There's foam in the fuel cell to keep the gas from sloshing around. It deteriorated.. .and is stuck in the fuel line. I sent a pic to Jason and asked him to post it...as I haven't got internet on my phone.
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Damn! Never saw that, but I have not looked in many fuel cells, either! good catch! That will do it for sure!
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Posting for Brad. Same thing happened to my father in laws fuel cell in his Galaxie. We pulled the pump apart and there was foam debris on the inlet side of the pump.
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Yuck.
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Thanks for posting Jason. They removed the fuel cell and pulled all the foam out.
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Jesus! How old is the cell?
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Dan brought it up from Florida about 6 weeks ago. It had been sitting in storage for 2 years. The race gas in it deteriorated the foam. It was a nut and bolt restoration... and built professionally for racing in a certain class. You can see a weight box in front of the fuel cell. I'm hoping to convince Dan to race it in the Nostalgia class at SMP with me. Nostalgia is 1975 and older.
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Update. With the fuel line unclogged...th e fuel pressure is holding steady at 6 PSI.
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Guess the filter came to good use...glad that issue has been addressed