fuel or timing issue

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fuel or timing issue

Post  emptypockets on August 19th 2017, 10:07 am

I have a 69 460 stock bottom end doore heads, stealth intake, 1 inch spacer,1050 quick fuel carb, edlbrock rpm cam and springs, this is a parts lying around build. breaks down at 5400rpm. have davis unified hei distributer set at 35degrees all in at 2500rpm or so. richened the secondaries to 106 made a difference. it should turn to 6000rpm I would think
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Re: fuel or timing issue

Post  rmcomprandy on August 19th 2017, 12:22 pm

emptypockets wrote:I have a 69 460 stock bottom end doore heads, stealth intake, 1 inch spacer,1050 quick fuel carb, edlbrock rpm cam and springs, this is a parts lying around build. breaks down at 5400rpm. have davis unified hei distributer set at 35degrees all in at 2500rpm or so. richened the secondaries to 106 made a difference. it should turn to 6000rpm I would think

There must be a bottleneck somewhere in there ... all you gotta do is identify it.
That total timing sure is close enough.

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Re: fuel or timing issue

Post  maverick on August 19th 2017, 12:26 pm

Were the valve springs among the parts lying around?
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Re: fuel or timing issue

Post  emptypockets on August 19th 2017, 12:44 pm

springs are new
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Re: fuel or timing issue

Post  supervel45 on August 19th 2017, 2:22 pm


Did you look at the spark plugs?

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Re: fuel or timing issue

Post  BBFTorino on August 19th 2017, 2:32 pm

What size fuel line and system? What PSI into the carb?

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Re: fuel or timing issue

Post  supervel45 on August 19th 2017, 3:19 pm

Power Valves Blocked? Front Jet Sizes? Type fuel?

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Re: fuel or timing issue

Post  emptypockets on August 19th 2017, 5:08 pm

Plugs are tint brown. #8 fuel line. Holley 110 gph pump. Primery jets are 1 down from what carb came with.
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Re: fuel or timing issue

Post  emptypockets on August 19th 2017, 5:09 pm

Running vp110
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Re: fuel or timing issue

Post  supervel45 on August 19th 2017, 5:38 pm

https://www.summitracing.com/parts/qft-q-1050

Is it by chance this 1050? I was thinking Dominator until I remembered Stealth intake. That is why I asked about the type of fuel at your jet size.

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Re: fuel or timing issue

Post  supervel45 on August 19th 2017, 5:45 pm

Fuel filter type and is it clean and not restricted? Any cartridge filters behind the fuel inlet fittings?

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Re: fuel or timing issue

Post  emptypockets on August 19th 2017, 8:53 pm

That's the quick fuel carb. Have good fuel filter. No filters in inlets. Could air bleeds have effect on it. Runs good. Pulls hard to 5400rpm
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Re: fuel or timing issue

Post  supervel45 on August 19th 2017, 10:10 pm

emptypockets wrote:That's the quick fuel carb. Have good fuel filter. No filters in inlets. Could air bleeds have effect on it. Runs good. Pulls hard to 5400rpm

That's a very detailed topic. Short answer yes, longer answer is if they are stock air bleeds I think you are on the wrong trail. The secondary jet size you are at (106)  and factory jets for that QFT lead me to my present conclusion.

PS: If you want a better knowledge of air bleeds go to Racing Fuel Systems and study the topic.

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Re: fuel or timing issue

Post  supervel45 on August 19th 2017, 10:26 pm

One of the fastest cheapist ways to get a handle on fuel delivery problems is a visible fuel pressure gauge on a WOT pass.

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Re: fuel or timing issue

Post  emptypockets on August 20th 2017, 7:14 am

Thanks for the information.
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Re: fuel or timing issue

Post  zbob on August 20th 2017, 8:40 am

I had a stack of errors (mine) that had similar rpm brick wall. it would spit, miss fire and just stop accelerating.
..... I had run the magnetic pick up to the msd distrib along with the original harness. it is now right down the head intake all alone. I believe the alternator/regulator wiring was disrupting the pick up coil.
......the other thing I did was assemble the holley billet fuel filter backwards and was using it as a pre pump strainer. didn't help the fuel flow at all. I now have a wix diesel truck strainer in front of the pump and the filter correctly assembled as a after pump filter. I separated the float bowl lines to the holley supplied regulator(holly blue pump and reg). I had originally plugged one end on the regulator and fed the carb with one line. I also moved the reg right up to the carb.
....finally I raised the float level to the upper half of the sight glass. installed taller bowl vents. just in case. my carb is a 850 proform unit. for what it is worth I have it sitting on a one inch closed spacer and then a open spacer to a torker II intake. funny thing about the carb>when I disassembled it for a through cleaning the main body had quick fuel embossed on it, go figure.
.....now it runs up to 5400 rpm and with a juice cam it is what I expected. good luck. bob

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Re: fuel or timing issue

Post  supervel45 on August 20th 2017, 3:19 pm

zbob wrote:I had a stack of errors (mine) that had similar rpm brick wall. it would spit, miss fire and just stop accelerating.
..... I had run the magnetic pick up to the msd distrib along with the original harness. it is now right down the head intake all alone. I believe the alternator/regulator wiring was disrupting the pick up coil.
......the other thing I did was assemble the holley billet fuel filter backwards and was using it as a pre pump strainer. didn't help the fuel flow at all. I now have a wix diesel truck strainer in front of the pump and the filter correctly assembled as a after pump filter. I separated the float bowl lines to the holley supplied regulator(holly blue pump and reg). I had originally plugged one end on the regulator and fed the carb with one line. I also moved the reg right up to the carb.  
....finally I raised the float level to the upper half of the sight glass. installed taller bowl vents. just in case. my carb is a 850 proform unit. for what it is worth I have it sitting on a one inch closed  spacer and then a open spacer to a torker II intake. funny thing about the carb>when I disassembled it for a through cleaning the main body had quick fuel embossed on it, go figure.
.....now it runs up to 5400 rpm and with a juice cam it is what I expected. good luck. bob

The little things stack up don't they Bob. That's why I ask so many questions,LoL

Quite telling Proform makes QFT parts now owned by Holley. Lot of China Junk getting mixed in now days. Biggest problem I have with all that is the rubber components and 10% alky fuel or even straight gasoline. Pisses me off to no end as it is made to fail and they bend you over for better stuff when that's all they should carry in the first place.

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Re: fuel or timing issue

Post  supervel45 on August 20th 2017, 3:26 pm

Holley Fuel Injection=Apples IPhone Caching$$$$$$$$$$ Suspect Think about it. Laughing

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Re: fuel or timing issue

Post  BOSS 429 on August 20th 2017, 6:01 pm

emptypockets wrote:I have a 69 460 stock bottom end doore heads, stealth intake, 1 inch spacer,1050 quick fuel carb, edlbrock rpm cam and springs, this is a parts lying around build. breaks down at 5400rpm. have davis unified hei distributer set at 35degrees all in at 2500rpm or so. richened the secondaries to 106 made a difference. it should turn to 6000rpm I would think

try a diff carb on it, 106 jet?

whats in the front? power valve?
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Re: fuel or timing issue

Post  emptypockets on August 22nd 2017, 4:27 pm

I'm gonna mess with it. gotta be something simple
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Re: fuel or timing issue

Post  cool40 on August 22nd 2017, 10:18 pm

What's your air cleaner setup? Suspect
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Re: fuel or timing issue

Post  supervel45 on August 23rd 2017, 12:33 am

You might try pulling a hot wire straight off the battery to the power the HEI and see what happens. Also disconnect the tach if that does not help in case it or the wire is grounding somehow. Just a couple of ideas and you can rule out a couple of things easily.

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Re: fuel or timing issue

Post  rmcomprandy on August 23rd 2017, 10:11 am

supervel45 wrote:You might try pulling a hot wire straight off the battery to the power the HEI and see what happens. Also disconnect the tach if that does not help in case it or the wire is grounding somehow. Just a couple of ideas and you can rule out a couple of things easily.

YEP ... those things use a lot of current and need a relay installed in order to work well on a vehicle which was not originally available with them.

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Re: fuel or timing issue

Post  emptypockets on August 23rd 2017, 5:12 pm

no factory wiring. push button start. 70 amp push pull for ignition strait from battery. 14 inch x 6 tall k&n air filter
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Re: fuel or timing issue

Post  supervel45 on August 23rd 2017, 6:37 pm

You might try raising the float levels some front and rear and see if it makes any improvement on a short run. Don't raise them until they start dribbling out the boosters though. If it does improve, it will point you more to a fuel delievery problem if it is sucking the bowls down at WOT. Running on a low tank of gas can also show the same symptoms by uncovering the pickup line. Like I mentioned before having a fuel pressure gauge you can see from the cab really helps on these deals.

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