Engine cutting out
Thread Starter
Instructor
Joined: Jan 2012
Posts: 215
Likes: 6
From: Mebane, NC
Engine cutting out
Took a road trip over the weekend. Car was running fine at 70 on the interstate until we got to the steep 3 mile hill over the Blue Ridge Mountains. As I added more gas to maintain speed the engine started stumbling and loosing power. Back off on the throttle all is fine again. I'm thinking the secondaries aren't working correctly. Is it possible to clean them without dissassembling the carb? Not afraid of a rebuild if that is necessary, hoping for a quick fix while I still have some good driving weather. I have not yet checked the timing, will do that soon.
Race Director
Joined: May 2006
Posts: 18,737
Likes: 2,583
really doubt the secondaries would be the issue since you would have to have your foot really into it before they would start opening. When is the last time you checked the basics, not sure what year you have, if points, dwell and timing, plugs, cap, rotor, fuel filter. You also dont mention what carburetor you have?
Drifting
Joined: Jul 1999
Posts: 1,542
Likes: 43
From: Plano TX
If your car is HEI equipped this is also a sign the HEI ignition module failure. They may also run fine until engine heat gets to the module.
If this is the problem also replace the rotor as it will have burned through causing arcs to the module (a lot of rust looking stuff on the advance weights)
Dave
If this is the problem also replace the rotor as it will have burned through causing arcs to the module (a lot of rust looking stuff on the advance weights)
Dave
2026 Loser of the Year
Joined: Sep 2013
Posts: 36,599
Likes: 7,046
From: New Or-leens Loo-z-anna
I just went through a similar problem this week...check the spark first...a blue spark about 3/4 inch long should jump when you remove the boot and hold it near a non-painted metal/area/spot with the engine running......a bright orange spark will only cause more problems like loss of power/poor gas mileage.
Then check everything else....I ended up having to disassemble the carb---I removed the top plate...the jets were nearly stopped up with fine trash. The small ifilter in the carb inlet had disintegrated....I also added a "see=thru" in-line filter between the fuel pump and the carb for extra protection.
Then check everything else....I ended up having to disassemble the carb---I removed the top plate...the jets were nearly stopped up with fine trash. The small ifilter in the carb inlet had disintegrated....I also added a "see=thru" in-line filter between the fuel pump and the carb for extra protection.
Last edited by doorgunner; Nov 10, 2014 at 05:03 PM.
Thread Starter
Instructor
Joined: Jan 2012
Posts: 215
Likes: 6
From: Mebane, NC
more info
Thanks. All usefull information. Will start troubleshooting tomorrow. '73 car, '81 350 with a slightly more aggressive cam (no details PO installed), 4 speed, quadrajet, no HEI. No pinging, slight backfireing on deceleration. Couple years but only a 800-1000 miles since last tune up. Gas was fresh.
Thread Starter
Instructor
Joined: Jan 2012
Posts: 215
Likes: 6
From: Mebane, NC
Thanks
The fuel tank is new, don't think the problem is at that end. I haven't looked at a diagram yet, assume the carb filter is where the line enters the carb. Is it a clean and reuse or do I buy a replacement. Also been reading other posts. They say to pull off the top to check float levels, clean jets, etc. Can the gasket be reused, I'm guessing it is paper and will probably tear. Can they be purchased seperately or do I need to buy a whole kit? Dr appts and honeydos...won't get to the car for a couple days.
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
I agree with reelav8r, sounds like a fuel problem. If the tank and filter are good, the pump is next likely. I would check that before taking the top of the carb off. Stock replacement pumps are cheap.
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Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Filter in the carb inlet is a toss and replace item, paper filter. The carb gasket is paper like but durable. It can be ordered seperate from a kit. Have your carb number handy to do it to get the right gasket. If careful you should be able to re-use it.
Removing top of the carb can be intimidating if you've not done it before. Just be careful putting it back on to prevent bending your primary metering rods. It's not as easy as it sounds to get it right.
Removing top of the carb can be intimidating if you've not done it before. Just be careful putting it back on to prevent bending your primary metering rods. It's not as easy as it sounds to get it right.
Thread Starter
Instructor
Joined: Jan 2012
Posts: 215
Likes: 6
From: Mebane, NC
Jets
I've been rebuilding carbs...lawn mowers, chain saws, outboards, MGs, etc for many years. With the introduction of fuel injection my experience on car carburators has been little in the last couple decades. This is my first experience with the Quadrajet. When you say richen up the jets, I would assume you mean make them bigger. How does one do that? Parts replacement? Carefull use of a drill?