Discussion Forum - Northstar Chevelle Club

jim larson · 2K+ Club

Replace or just try to clean the old bronze fuel filter in the Holley?

dashboard · 2K+ Club

How long has the filter been in there? Pat at the Carb Shop told me a very high percentage of those filters are bad when new; he had a bag the size of a football full of bad ones.

Is this part of your won't go over 4000 rpm deal?

bowtie · Secretary

I thought there were aftermarket filters that fit in there that weren't the sintered bronze ones Might be another option. If you need to go original, remember that they used 2 different ones (long and short if I remember correctly), bring yours to compare.

jim larson · 2K+ Club

dashboard wrote:
How long has the filter been in there? Pat at the Carb Shop told me a very high percentage of those filters are bad when new; he had a bag the size of a football full of bad ones.

Is this part of your won't go over 4000 rpm deal?

It will go over 4000 and up to 5000; but it kind of sputters or misses.

SShink · 3K+ Club

I would start checking ignition parts. Is it points or HEI distributor?

Check the obvious, loose spark plugs or wires, moisture in the cap, points adj., rotor condition, etc.

Chris R · 2K+ Club

Does it sputter only under a load?

jim larson · 2K+ Club

dashboard wrote:
How long has the filter been in there? Pat at the Carb Shop told me a very high percentage of those filters are bad when new; he had a bag the size of a football full of bad ones.

Is this part of your won't go over 4000 rpm deal?

Kevin how to you tell they are bad? Are you refering to the clinder shaped filter with a cone shaped in the middle. Thanks.

jim larson · 2K+ Club

Chris R wrote:
Does it sputter only under a load?

@ WOT when running through the gears, happens about 4200 rpm.

jim larson · 2K+ Club

SShink wrote:
I would start checking ignition parts. Is it points or HEI distributor?
Check the obvious, loose spark plugs or wires, moisture in the cap, points adj., rotor condition, etc.

The old points system, I order a new set of points/condensor, since I figured after 5 yrs them maybe need to be replaced. New wires, dwell set at 29 degrees and doesn't seem to move. I'll have to check the cap and rotor, maybe t hrow on a different coil.

dashboard · 2K+ Club

Jim, I think the scientific method is to blow thru them; there should be almost no restriction. If you have a good one and a bad one there is a marked difference; it is possible to install them backwards and or incorrectly however.

Was the spring installed between the filter and the carb body?

How long has it been in there?

Really old filters can develop a varnish type coating that is restrictive. If the filter is/was installed correctly, fuel will by-pass these types filter if they become restricted so I would suggest this is not the problem if it was installed correctly. Your paper inline filter will not by pass however.

Have you checked both filters for traces of particulate contamination?

I think you’re going in the right direction with points and condenser first but………..it could be fuel.

Chris R · 2K+ Club

jim larson wrote:
Chris R wrote:
Does it sputter only under a load?
@ WOT when running through the gears, happens about 4200 rpm.

So if you were to do it at idle just sitting there. Does it sputter then as well? What if you rev it to 4200 when its parked in neutral?

Lost in the 60s · President

I know you want to keep things as original as possible, but I bought my last set of points several years ago. Since then I have installed Pertronix Ignitor III electronic ignition and black coils. I have installed 3 now and every one I could tell the difference as soon as it started. Much faster start, smoother idle and no miss, sputter as high as the cut-out is set for. You can open the gap on the plugs to .045 also for a stronger spark. They install in the original distributor and the only tell-tale sign is it has 2 wires coming out the bottom instead of 1.

dashboard · 2K+ Club

and if you put a piece of heat shrink over the two wires no one will ever know unless they remove the dizzy cap. The rev limiter is cheep insurance you can it at what ever RPM you want.

Now

John D · 2K+ Club

OK... lets look at this from a logical standpoint, and quit "throwing parts at it".

(assuming) that last "season" the car ran just the way it should... pulled hard and didn't have issues.
What has CHANGED since last fall??

Has the ignition system been altered?
Has the timing been changed?
Have the parts in the ignition system experienced any physical alterations other than 6 months of the calendar going by...?

Points don't go bad sitting in a distributor... (unless the key's been left "ON" and they happen to be closed), and plug wires won't be junk in 6 mos...

The item that has changed is the CRAP gasoline that was left in the fuel system... it isn't GAS anymore... it's the leftovers of methanol enriched pseudo fuel.

Think about it... What did you change since the last time the car ran well?

John D · 2K+ Club

To reiterate

I posted this awhile ago...

Lost in the 60s · President

I've had points sit open over a winter and get condensation corrosion on them and they never worked right again.

But YES, today's gas is crap. I always burn non-oxy in mine to avoid the ethynol and add a can of Sea Foam before parking for the winter.

Chris R · 2K+ Club

Your on the right track with the fuel system side of things. Ignition systems can handle sitting for long periods of time but gas doesnt like to sit around and can create problems in even a few months of sitting around. Ive had to pull the carb off my 66 a few times and clean the bowls because it didnt run right when I got it out of storage.

CDNSS · Member

I agree winter gas is not great and could be the issue but dependent on what brand of points you have in there they could be bouncing ....... the typical parts store points we get these days only last a few high rpm blasts then they start to bounce ........... so as already asked if this does it under free rev in neutral then you may want to check the points for bounce it will feel/ sound like a misfire

jim larson · 2K+ Club

Chris R wrote:
jim larson wrote:
Chris R wrote:
Does it sputter only under a load?
@ WOT when running through the gears, happens about 4200 rpm.
So if you were to do it at idle just sitting there. Does it sputter then as well? What if you rev it to 4200 when its parked in neutral?

It does it under load at WOT. It doesn't seem to do it, if car is is nuetral and run it up to 5000 rpm.

jim larson · 2K+ Club

John D wrote:
To reiterate
I posted this awhile ago...

Been out turkey scouting, then sleep, then snow and no electricity, computer just came on.

SShink · 3K+ Club

jim larson wrote:
Chris R wrote:
jim larson wrote:
Chris R wrote:
Does it sputter only under a load?
@ WOT when running through the gears, happens about 4200 rpm.
So if you were to do it at idle just sitting there. Does it sputter then as well? What if you rev it to 4200 when its parked in neutral?
It does it under load at WOT. It doesn't seem to do it, if car is is nuetral and run it up to 5000 rpm.

Sounds like possibly backpressure or an exhaust restriction. Do you have stock exhaust manifolds with the flapper door in the manifold for the heat riser tube? I had a similar problem at a lower rpm on a 327 that had stock manifolds and the flapper in it. Someone had wired the flapper open since it wasn't functional with the heat tube to the air cleaner anymore, and it partially closed on a cruise once, lost all power around 3000 rpm. Spent hours trying to figure it out then accidently bumped the flapper connection and discovered it had closed causing backpressure in the passenger side cylinders.

Chris R · 2K+ Club

jim larson wrote:
Chris R wrote:
jim larson wrote:
Chris R wrote:
Does it sputter only under a load?
@ WOT when running through the gears, happens about 4200 rpm.
So if you were to do it at idle just sitting there. Does it sputter then as well? What if you rev it to 4200 when its parked in neutral?
It does it under load at WOT. It doesn't seem to do it, if car is is nuetral and run it up to 5000 rpm.

Then your likely problem is fuel delivery then. Fuel system keeps up with the RPM's when there isnt a load and once you try to drive it. The load on the engine trying to move the car is too much for the fuel system to keep up with.

First thing I would do is put a fuel pressure gauge between the pump and filter and see where your at. 99% of the time, if the engine can rev without a load just fine, then your ignition system is suffice enough to supply enough spark when its under load too.

Ignition systems do not care what kind of load is on an engine. They just need to know what RPM to deliver the spark at. Fuel systems however, are dependant on the load of the engine. Its a carburator after all and a carbs main operating requirement is based on vacuum, when the vacuum is at max, your engine has no load on it and drawing fuel in takes very little effort thanks to the venturi effect. Once the RPM gets up there with a load of thousands of lbs from the weight of the car being put against it. The vacuum drops even further and if there is any varnish or debris preventing the fuel from being drawn in thanks to the extra demand, the fuel system cant keep atomizing enough fuel entering the intake and thus the engine stumbles. In a sense, the engine is leaning out at the high RPM's under load. It sounds like there is some debris trapped from this past storage season. Even a can of carb cleaner and some compressed air might do the trick.

Ive never had a holley with the bronze filter but is it possible to remove it and blow it out with some compressed air and put it back in and try it?

jim larson · 2K+ Club

Sounds like possibly backpressure or an exhaust restriction. Do you have stock exhaust manifolds with the flapper door in the manifold for the heat riser tube? I had a similar problem at a lower rpm on a 327 that had stock manifolds and the flapper in it. Someone had wired the flapper open since it wasn't functional with the heat tube to the air cleaner anymore, and it partially closed on a cruise once, lost all power around 3000 rpm. Spent hours trying to figure it out then accidently bumped the flapper connection and discovered it had closed causing backpressure in the passenger side cylinders.

Stock manifolds with heat riser installed, except I removed the inside flapper door, so it only looks stock.

-- Edited by jim larson on Friday 3rd of May 2013 05:37:31 PM

jim larson · 2K+ Club

Chris R wrote:

Then your likely problem is fuel delivery then. Fuel system keeps up with the RPM's when there isnt a load and once you try to drive it. The load on the engine trying to move the car is too much for the fuel system to keep up with.
First thing I would do is put a fuel pressure gauge between the pump and filter and see where your at. 99% of the time, if the engine can rev without a load just fine, then your ignition system is suffice enough to supply enough spark when its under load too.
Ignition systems do not care what kind of load is on an engine. They just need to know what RPM to deliver the spark at. Fuel systems however, are dependant on the load of the engine. Its a carburator after all and a carbs main operating requirement is based on vacuum, when the vacuum is at max, your engine has no load on it and drawing fuel in takes very little effort thanks to the venturi effect. Once the RPM gets up there with a load of thousands of lbs from the weight of the car being put against it. The vacuum drops even further and if there is any varnish or debris preventing the fuel from being drawn in thanks to the extra demand, the fuel system cant keep atomizing enough fuel entering the intake and thus the engine stumbles. In a sense, the engine is leaning out at the high RPM's under load. It sounds like there is some debris trapped from this past storage season. Even a can of carb cleaner and some compressed air might do the trick.
Ive never had a holley with the bronze filter but is it possible to remove it and blow it out with some compressed air and put it back in and try it?

Fuel is where my focus is. Still snowing this morning. When the snow is gone and it warms up, the next step is to burn all old gas out, fill with new gas , octane supreme 130, and a can of seam foam. Then install a new fuel filter ( bronze type.

jim larson · 2K+ Club

I just bought the filter today and took out the old one. Parts guy said not to handle it with greasy old hands. Now, which way does it go in? Don't know if the one I am taking out was installed correctly.

Parts guy also said maybe adding the additional filter I installed back between the gas tank and the start of the hard line to the front caused to much restriction. Any thoughts on that comment.

dashboard · 2K+ Club

Here's what Holley had in mind.

http://www.vintagemusclecarparts.com/pages/filterreplace1.html

jim larson · 2K+ Club

dashboard wrote:

Here's what Holley had in mind.

http://www.vintagemusclecarparts.com/pages/filterreplace1.html

Kevin, this guy is the expert when it comes to holley carbs. His name is Eric Jackson. Eric sent me the information about 30 minuets ago. Thanks.

dashboard · 2K+ Club

Everyone will have a opinion, here’s mine.

I would remove the filter prior to the fuel pump and use the bronze carb filter or replace it with an inline filter between the fuel pump and the carb. Fuel or any liquid for that matter should be pushed through a filter, not pulled through it. Unless you have gross contamination in your fuel tank anything in the fuel, be it particulate or moisture will move through your factory fuel pump.

When the engineer designed the fuel system he settled on that little bronze filter after talking with the guys at Holley and Rochester. That system worked well for a lot of years until on some cars it was replaced with a inline paper filter between the fuel pump and the carb.

A fuel pump needs a uninterrupted, unrestricted flow of fuel to it, any restriction will lead to cavitation or air bubbles in the fuel feed line. This is further aggregated by the low boiling point of our current gasoline at sea level. The stuff that comes out of the pumps today will boil at temps as low as 100 degrees at sea level, even lower temps if it in an aerated state. It is designed for fuel injected car where the fuel is kept under much greater pressure from the fuel tank to the injector

I can not think of a single application where a fluid filter is installed on the low pressure side of a pump, not oil, water, fuel, or hydraulic. The only use of a filter before a pump I can think of is in a air compressor.

Just my

What did your expert think about the extra filter?

Chris R · 2K+ Club

I didnt realize you had a filter on the low side of the system either and Kevin nails another good point. I would loose the low side fuel filter asap. Fuel pumps need to build as much suction as they can without restriction and going from the back of the car all the way up to the front should not have any restrictions in it. The engineers felt the sock inside the tank (which could also be part of the problem as well by the way) is enough to keep debris out and have the fuel system work just fine as well as keeping the restriction down to a minimum.

If the car was running just fine last year, I would pull the old filter out of the carb and match up the new one and re-install. Then get rid of the filter that is near the back of the tank.

jim larson · 2K+ Club

dashboard wrote:

I can not think of a single application where a fluid filter is installed on the low pressure side of a pump, not oil, water, fuel, or hydraulic. The only use of a filter before a pump I can think of is in a air compressor.

Just my
What did your expert think about the extra filter?

I didn't mention to Eric that I had installed a filter between the Tank and the Fuel pump.

Thanks for the advice Kevin and Chris. It will be removed today.

Lost in the 60s · President

I have an in-line filter on my Camaro in the rubber hose from the frame to the pump and it doesn't seem to affect performance at all. The '66 had one back at the tank and it reduced flow/pressure. I moved it up to the engine compartment.

dashboard · 2K+ Club

Just out of curiosity does the Camaro have a 5/16” fuel line and the Chevelle a 3/8”? Could that be the higher demand of the big block?

Chris R · 2K+ Club

Could be that the filter in Mitches Camaro has less resistance to pull through. It might also be that the Camaro has a shorter distance to pull fuel out of the tank then the Chevelle does. Thats a bit far fetched though but the gas that was used could be different between both cars too and even the good quality gas from one car to the next can create problems, gasonline doesnt like to sit around. Which is typically why myself and most others add additives like seafoam to the gasoline, keeps moisture down among other things.

How often did you drive the car last year Jim? Enough to run several tanks through it or is it a special occasion or show only type car? I know Mitch drives the hell out of both the Camaro and Chevelle.

jim larson · 2K+ Club

Probably about 800 miles @ 12 mpg, so about 70 gallons of gas. Filled last fall and added the marine grade stabelizer, lead, and a little MO. I just removed the filter back by the tank. I have an original NOS fuel pump, that was the factory pump used on the 66 360HP cars.

We'll see how it runs when the snow melts.

Lost in the 60s · President

dashboard wrote:
Just out of curiosity does the Camaro have a 5/16” fuel line and the Chevelle a 3/8”? Could that be the higher demand of the big block?

Both 3/8 ths. The Camaro is a factory SS car too.

I buy all the non-oxy premium at the same station.

Jon H · 1K+ Club

Jim, If the problem persists try leaving the bronze filter out of the carb. for a test run. I ran my old carb for several years without the in carb filter with no issues as I had the other inline filter.

SShink · 3K+ Club

Jim, saw this on TC and thought of your issue: http://www.chevelles.com/forums/showthread.php?t=439594

Have you double checked your timing? For some reason, I think you had issues last year with the timing?

jim larson · 2K+ Club

SShink wrote:
Jim, saw this on TC and thought of your issue: http://www.chevelles.com/forums/showthread.php?t=439594
Have you double checked your timing? For some reason, I think you had issues last year with the timing?

Thank for thinking of me. Interesting article. I installed new valve spring a couple of years again, thinking they are still good, I hope. Settled on the fuel or ignition issue, so waiting to run all the old gas out, I removed the fuel filter back by the gas tank and installed a new filter in the carb. When I put in new gas, I will also add some sea foam. I check the dwell and timing and they seem good ( 14* and 29*respectively); but its an old dwell meter and I am not confident it stays set up to 5000 rpm. As Chris indicated that if there were no issues when not under load, most likley a fuel problem. Hope that is true. Just bad gas hopefully and not a bad fuel pump. I picked up a new set of points an condenser from a Northstar Camaro Club guy at the swap meet on Sunday, so if new fuel doesn't work, I will throw those in the distributor. Then maybe a new pentronix unit.

The timing issue was that of having it set to low and as a result it caused the engine to overhead to the point that the radiator couldn't cool the engine on those 90+ day.

67ss · 1K+ Club

I just rebuilt a quadrajet the other day that had a bronze filter in it. I threw it away and used the short paper filter. Will the small quadrajet paper filter fit into the holley. I have not tried it myself but just a thought.

jim larson · 2K+ Club

Car is running fine again. I removed the fuel filter from back by the gas tank. Put in a new filter at the carb ( the old bronze type). New gas after burning out most of the old gas (91 non-oxy), added a can of sea foam and a little lead, and 10 oz of Octane supreme 130. I think I should put in a pentronix unit just to see how that seems to work.

CDNSS · Member

Good , certainly did not hurt to change out those filters but my guess it was the gas going thru that right now with my and other musclecar i help tune ......even my car witha drained tank in fall now with fresh "winter " gas we still have here runs like crap other car had old gas and missing under load , it was actually detonating on the old gas pbly had water in it

. FWIW I set points at 32* dwell on all the GM point dist I tune ( have sun machine do alot for the resto guys here ) plus when you put new points in after it runs for a short while . recheck they can change a bit reset and your good for long time ......... Pertonix etc ............ nothing wrong with those kits but they really do not give enough if any of a stronger spark ........i know they say they do .....they just replace the points as a trigger with an electronic trigger albeit more reliable . but quality points with a good coil will be fine ................ a nice electronic point conversion for a stock engine is the one made by "Lectric " installs with no change to your stock resister wiring same single wire coming out of dist as point dist etcetc good idea for resto cars that sit alot as points can get a build up on contacts from humidty if they sit along time between runnning