Ford Muscle Cars Tech Forum banner

331 Stroker Misfire / Stall

3K views 6 replies 3 participants last post by  ethanwk 
#1 ·
Hello everyone,

I'm new to this forum as a poster, but have read countless topics over the years. You all are a huge help.

I've been having a really annoying issue lately since the weather has turned colder. Recently, I've developed a misfire / stall when the engine is relatively cold. After about 15 minutes of driving, it seems to improve but it'll dang near die at stop signs until it's been "warmed up" (middle of water temp gauge) for about 10 minutes. Below are my engine stats as well as a couple things I've tried. Any help is welcome!

331 stroker
Mild "street" cam (not sure of exact specs, but definitely not a stock cam)
Edelbrock RPM heads
 
#2 ·
Car / Motor Setup

65 mustang

331 stroker
C4 Transmission
Mild "street" cam (not sure of exact specs, but definitely not a stock cam)
Edelbrock RPM heads
Headers
Performer 289 intake
Holley 4160 carb (haven't rebuilt it yet)
1" Carb Spacer
Mallory unlilite distributor
Accel Super Stock Coil
8mm Wires
Autolite 3924 spark plugs (.04 gap)
Timing: 13 Degrees initial about 36 degrees total @ 3500rpm
No Vacuum advance (it has never had it since I've owned the car, and the motor runs really bad with both ported and manifold vacuum)
Manual Steering, Manual brakes
 
#3 ·
Things I've done to try to fix the issue:

Sprayed starter fluid all over exposed intake seams, carb base, and PCV hose / Fitting.
checked PCV Valve (it shakes around like its supposed to)
Sucked air through PCV hose (it holds pressure)
Checked all vacuum ports on carb to confirm they're plugged
New Wires
New plugs (3924 gapped at .04)
installed a known good coil (the motor actually ran worse than with the super stock)
tried a different fuel pump (no change)
New Fuel Filter
Sprayed some carb cleaner in the fuel bowl vents in case the carb was gummed up. (while running)
Adjusted the idle mixture with a vacuum gauge about a dozen times using the Holley published method.
Currently getting about 18 - 19 of vacuum.
Confirmed my accelerator pump was shooting a good squirt of gas.
New Choke cap (choke works beautifully)
new fast idle cam
 
#5 ·
Thanks for the reply!

I'll try adjusting the choke cap to keep it closed off longer when cold started. Good advice on the PCV valve. I figured if they weren't gunked up and stuck open / closed that they worked. Cant hurt to just replace it anyways.
 
#6 ·
Does it seem rich or lean? Does the exhaust burn your eyes? Problems like you describe are usually carburetor related. Either that, or vacuum leaks. Edelbrock carbs are generally the most 'user friendly' on street cars.

If I were to throw some money at your car in an effort to cure your issues of possible vacuum leaks and carb issues... as well as add some more power... I'd sell the Performer 289 intake (50 year old, restrictive design) and replace it with a more modern Performer RPM. You'll lose zero low end power, and pick up midrange and top end. I'd also replace the existing carb with an Edelbrock with a manual choke. The manual choke models have a more performance oriented tune. This way, you could eliminate vacuum issues with changing the intake, and rule out the carb.

As for intake gaskets, stay away from the Fel-Pro Print-O-Seals. They tend to tear over time, creating vacuum leaks. Also re-torque the intake bolts several times, as they tend to compress and settle. I actually GREASE the intake face of the gasket, so the manifold can slide down into place without tearing the gasket.

Good Luck
 
#7 ·
Well, I'm happy to update that a new pcv valve from Napa really improved my idle. The new valve seems to have a heavier internal piece that doesn't seem to open and close as easily as the old one. I put the new valve in, and re-tuned the carb and she seems to run much more confidently at idle. Hopefully this was the issue. only time will tell.

Thanks for chiming in, everyone. I'll update if the problem persists.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top