Need Some Help please

4 SPEED

4 SPEED

Well-known member
Joined
Jul 21, 2009
Messages
78
Location
New Jersey
My 74 was running fine today and then gave her some gas in second she started to bog down bigtime.
It got worse when I tried to move from a redlight, started breaking up real bad,almost didn't make it home.

Any suggestions welcome.
 
350 with Holley DP 700CFM
Electronic ignition

I was to keep going as long as I keep at an even speed.
Had to take it very slow in low gears
 
Fuel filter or fuel pump.. The electronic ignition is most likely an either it works or it doesn't thing. Most electronics are. Might also be a fuel feed problem, like a crack in a pickup hose, but I'd lean more toward a filter or pump.
 
when was the last time you filled it up?
depending on where you live, this could be the time of year your stations are changing their blends - so they run their tanks pretty low... which since water is heavier than fuel - causes problems
 
TimAT said:
Fuel filter or fuel pump.. The electronic ignition is most likely an either it works or it doesn't thing. Most electronics are. Might also be a fuel feed problem, like a crack in a pickup hose, but I'd lean more toward a filter or pump.
Click to expand...

I agree. Check your fuel pump. Fuel, air, spark.
 
Fuel pump is brand new and worked fine.
My experiece with fuel pumps is they work fine or they dont work at all.
This problem only happens when I start to give the engine gas and then it starts breaking up and bogs down. (doesn't do it if I rev at a standstill only when moving under a load)
I will replace the gas filter but my experience with filters is it's gradule thing over time and then your car wont run at all.
I am thinking maybe apower valve went on me.
I will call Holley today and get some feedback.
Sprayed the carb real good last night with gunk and soon as the rain stops I will see if it makes a difference.

Thanks for the input
 
When you say it "starts breaking up", I'm guessing that it's missing, and sputtering correct? Sounds like it might be going rich under a load, could it be a vacuum issue, or since this is a DP, maybe one of the pumps on the carb is giving you a problem. Have you looking down the carb to make sure both sides are squirting?
 
it sure sounds like a plugged filter - on my end of the world, that's a common problem right about now because the newly-added alcohol does a good scrub on the tank

if it free revs, then maybe look at the secondaries and the spark advance system - such as a messed up weight, or a vacuum canister that isn't working.
 
I called Holley before and They also said it is probably the in line filter.
I will replace that ASAP.
Will also dump some fuel cleaner in the tank.

Stay tuned
 
Last edited:
Check the fuel system as mentioned and if nothing found move on to ignition. If an HEI system they can fail. If the module they will run but miss when you hit the gas pedal as it can't fire the richer mixture. Modules fail when rotor goes bad and spark goes through rotor to module. If pickup coil car usually won't run at all.
 
daveL82 said:
Check the fuel system as mentioned and if nothing found move on to ignition. If an HEI system they can fail. If the module they will run but miss when you hit the gas pedal as it can't fire the richer mixture. Modules fail when rotor goes bad and spark goes through rotor to module. If pickup coil car usually won't run at all.
Click to expand...

that's a new one on me - when the module fails for me it doesn't work at all.
 
SuperBuickGuy said:
daveL82 said:
Check the fuel system as mentioned and if nothing found move on to ignition. If an HEI system they can fail. If the module they will run but miss when you hit the gas pedal as it can't fire the richer mixture. Modules fail when rotor goes bad and spark goes through rotor to module. If pickup coil car usually won't run at all.
Click to expand...

that's a new one on me - when the module fails for me it doesn't work at all.
Click to expand...

I agree, but I have rarely had a REAL GM module fail, aftermarkets, yes.....and another cutsey little failure I caught pants down, the HEI in cap coils have crimped connectors on the solid core wire primary, they go to the + and tach/control module...Well they didn't clean the wire off the formvar it was made with, and so I caught one with no +12 on the tach side, and I"m thinking the coil is flamed, looked totally normal, soldered the connections, off and running for years.....go figger, ever since then, I solder ALL of them HEI coils, OH, and just for shits and grins, make damn sure that coil frame is actually connected to the middle/ground and don't ask me how I know this,

Ok, I fess up, I left off a ground wire, and the thing was arcing over to one of the other two connectors, and it burnt hell out of the coil/cap/etc....engine ran fine for a while, but when the crap hit the cap it started to run like shit, and when I pulled that coil cover....:suicide::sos::lol:
 
had the ignition module fail on a 3.8L V6 ..... it did exactly what you describe.... idles fine and sputters under load, will stall at full throttle.....

not saying this is your problem, just a possibility worth looking into if the fuel filter turns out to be ok and fuel supply is not the issue.........
 
mrvette said:
SuperBuickGuy said:
daveL82 said:
Check the fuel system as mentioned and if nothing found move on to ignition. If an HEI system they can fail. If the module they will run but miss when you hit the gas pedal as it can't fire the richer mixture. Modules fail when rotor goes bad and spark goes through rotor to module. If pickup coil car usually won't run at all.
Click to expand...

that's a new one on me - when the module fails for me it doesn't work at all.
Click to expand...

I agree, but I have rarely had a REAL GM module fail, aftermarkets, yes.....and another cutsey little failure I caught pants down, the HEI in cap coils have crimped connectors on the solid core wire primary, they go to the + and tach/control module...Well they didn't clean the wire off the formvar it was made with, and so I caught one with no +12 on the tach side, and I"m thinking the coil is flamed, looked totally normal, soldered the connections, off and running for years.....go figger, ever since then, I solder ALL of them HEI coils, OH, and just for shits and grins, make damn sure that coil frame is actually connected to the middle/ground and don't ask me how I know this,

Ok, I fess up, I left off a ground wire, and the thing was arcing over to one of the other two connectors, and it burnt hell out of the coil/cap/etc....engine ran fine for a while, but when the crap hit the cap it started to run like shit, and when I pulled that coil cover....:suicide::sos::lol:
Click to expand...

at least you don't do any of that regular stuff when you blow it up
 
SuperBuickGuy said:
mrvette said:
SuperBuickGuy said:
daveL82 said:
Check the fuel system as mentioned and if nothing found move on to ignition. If an HEI system they can fail. If the module they will run but miss when you hit the gas pedal as it can't fire the richer mixture. Modules fail when rotor goes bad and spark goes through rotor to module. If pickup coil car usually won't run at all.
Click to expand...

that's a new one on me - when the module fails for me it doesn't work at all.
Click to expand...

I agree, but I have rarely had a REAL GM module fail, aftermarkets, yes.....and another cutsey little failure I caught pants down, the HEI in cap coils have crimped connectors on the solid core wire primary, they go to the + and tach/control module...Well they didn't clean the wire off the formvar it was made with, and so I caught one with no +12 on the tach side, and I"m thinking the coil is flamed, looked totally normal, soldered the connections, off and running for years.....go figger, ever since then, I solder ALL of them HEI coils, OH, and just for shits and grins, make damn sure that coil frame is actually connected to the middle/ground and don't ask me how I know this,

Ok, I fess up, I left off a ground wire, and the thing was arcing over to one of the other two connectors, and it burnt hell out of the coil/cap/etc....engine ran fine for a while, but when the crap hit the cap it started to run like shit, and when I pulled that coil cover....:suicide::sos::lol:
Click to expand...

at least you don't do any of that regular stuff when you blow it up
Click to expand...

I tend to learn the hard way....and all this shit was pre internet and maybe 4-5 guys I could call, most of them getting laid, some of them racing, all of us working 40+, and a JOB, like ...... plus hanging our own cars together, best we could......

And so, I trying to help my son get a LS into his '57 Chebby pickup.....

going to be interesting....me in Florida, him in Kalifornia.....:surrender::smash::smash:
 
Ok, I added some fuel line cleaner and dry gas.
It seems to be running a little better but when I give it some gas it surges.
Before it would just bog down.
Next step is to change out the fuel filter.
If that doesn't work then to the electrical I go.
 
before you do that, get carb cleaner dowse out the air bleeds and general throttle body.

Also, I presume holley carb (since you called them). You may wish to do a quick clean/rebuild on the carb - especially check the booster, and (way outside the box, Mrvette issue) the power valve to see if it's ripped.

then check that vacuum advance is functioning, and whether or not the pins for the counterweights are worn....
 
Cleaned and inspected Holley Carb.
Added more dry gas
Changed gas filter

Car runs a little better but still surges a bit and there is some breaking up when I get on it.

Just ordered a new distributor from Summit Racing.
Was cheaper to buy new one then to rebuild the old one.
Stay tuned.
 
You must log in or register to reply here.
Top