76 stalling out
Thread Starter
Instructor
Joined: Nov 2012
Posts: 209
Likes: 7
76 stalling out
Hey guys, last year my 76 started developing a problem, it starts fine, idles fine, runs fine, but if you punch the gas (in gear) it wants to fall on its face and stall out. Reving the motor in park doesn't do it, I got to have the load of the vehicle on it.
I have the Holley Terminator efi and electronic distributor on my 350, the system uses 2 fuel filters and I'm wondering if one is getting plugged? Or if maybe I need to look into my distributor timing.
Also since I was being cheap at the time when I did the efi swap (i can't remember, 2012 maybe) I didn't buy a high end ignition coil, I just got the cheap msd blaster pack, maybe that ignition coil is going out? Maybe was never big enough to begin with....
I didn't work on this last year because expendable income was basic non-existent, something about starting my own business in a pandemic lol ... But I've lucky recovered and can finally work on my toys again. Thanks in advance.
I have the Holley Terminator efi and electronic distributor on my 350, the system uses 2 fuel filters and I'm wondering if one is getting plugged? Or if maybe I need to look into my distributor timing.
Also since I was being cheap at the time when I did the efi swap (i can't remember, 2012 maybe) I didn't buy a high end ignition coil, I just got the cheap msd blaster pack, maybe that ignition coil is going out? Maybe was never big enough to begin with....
I didn't work on this last year because expendable income was basic non-existent, something about starting my own business in a pandemic lol ... But I've lucky recovered and can finally work on my toys again. Thanks in advance.
Burning Brakes
Joined: Jun 2019
Posts: 1,209
Likes: 931
From: Georgetown, Tx
Another 76' guy here..
Unfortunately, this problem is difficult to ‘arm chair’ diagnose. Greg, many sub systems can present the same symptom you describe.
You can have lousy gas or a bad carb or a failing fuel delivery system. Vacuum leaks can cause timing problems and many old vettes are prone to cracked and leaking vacuum hoses; down to the transmission, too. You can have poor grounds or corrosion in electrical connectors dropping voltage. I’ve even seen a 76/77 vette with a plugged cat converter show the same symptom.
My suggestion is simple. Don’t chase ghost. Use basic troubleshooting techniques for automotive engines; fuel, air, fire. Begin with one sub-system and look it over very closely and then move to the next.
Start anywhere you care to, but inspect each subsystem thoroughly and one at a time. You know what to do!!
Unfortunately, this problem is difficult to ‘arm chair’ diagnose. Greg, many sub systems can present the same symptom you describe.
You can have lousy gas or a bad carb or a failing fuel delivery system. Vacuum leaks can cause timing problems and many old vettes are prone to cracked and leaking vacuum hoses; down to the transmission, too. You can have poor grounds or corrosion in electrical connectors dropping voltage. I’ve even seen a 76/77 vette with a plugged cat converter show the same symptom.
My suggestion is simple. Don’t chase ghost. Use basic troubleshooting techniques for automotive engines; fuel, air, fire. Begin with one sub-system and look it over very closely and then move to the next.
Start anywhere you care to, but inspect each subsystem thoroughly and one at a time. You know what to do!!
Last edited by 76-Vetteman; May 9, 2021 at 06:16 PM. Reason: typo
Thread Starter
Instructor
Joined: Nov 2012
Posts: 209
Likes: 7
Got it on the road today finally for the first time this year. I didn't think of it but maybe it could be a plugged catylitic converter...when I bought the car in '12 it had a Holley 650 dp and the exhaust always stunk of unburnt fuel and I could never dial the carb in right to get rid of it so I put two magnaflow cats on it and problem solved.
But now as I drove it today, it's way down on power, like I said it starts, idles, runs fine but give it some gas and it works hard to produce nothing. Now that I'm running an efi system maybe I can probably ditch the cats, maybe that old Holley carb had them close to plugged. Guess we'll see...
But now as I drove it today, it's way down on power, like I said it starts, idles, runs fine but give it some gas and it works hard to produce nothing. Now that I'm running an efi system maybe I can probably ditch the cats, maybe that old Holley carb had them close to plugged. Guess we'll see...
Le Mans Master
Joined: May 2007
Posts: 5,007
Likes: 1,114
From: North tonawanda NY
Hey guys, last year my 76 started developing a problem, it starts fine, idles fine, runs fine, but if you punch the gas (in gear) it wants to fall on its face and stall out. Reving the motor in park doesn't do it, I got to have the load of the vehicle on it.
I have the Holley Terminator efi and electronic distributor on my 350, the system uses 2 fuel filters and I'm wondering if one is getting plugged? Or if maybe I need to look into my distributor timing.
Also since I was being cheap at the time when I did the efi swap (i can't remember, 2012 maybe) I didn't buy a high end ignition coil, I just got the cheap msd blaster pack, maybe that ignition coil is going out? Maybe was never big enough to begin with....
I didn't work on this last year because expendable income was basic non-existent, something about starting my own business in a pandemic lol ... But I've lucky recovered and can finally work on my toys again. Thanks in advance.
I have the Holley Terminator efi and electronic distributor on my 350, the system uses 2 fuel filters and I'm wondering if one is getting plugged? Or if maybe I need to look into my distributor timing.
Also since I was being cheap at the time when I did the efi swap (i can't remember, 2012 maybe) I didn't buy a high end ignition coil, I just got the cheap msd blaster pack, maybe that ignition coil is going out? Maybe was never big enough to begin with....
I didn't work on this last year because expendable income was basic non-existent, something about starting my own business in a pandemic lol ... But I've lucky recovered and can finally work on my toys again. Thanks in advance.
Last edited by augiedoggy; May 10, 2021 at 12:30 PM.
Thread Starter
Instructor
Joined: Nov 2012
Posts: 209
Likes: 7
Yeah between the efi ECU and electronic distributor they do control the timing, and does use an O2 sensor. If I get it out again soon I'll check the air/fuel ratio, it hasn't thrown up any errors or faults yet.
