I want to get my car ready to do some summer cruising and have run into an annoying problem. When I bought the car I noticed that if you punched the gas it would bog down and sometimes die. I replaced the sparkplug wires, cap and rotor and am still having the same problem along with a backfire now. At idle or slow acceleration it seems to run fine but punch the throttle and POP-chug-chug-die. The previous owner said he rebuilt the carb(2bbl) and I have new plugs to put in just havent done it yet. I am having a brain fart though trying to think of the cause of the backfire. Its been awhile since I had something to tinker with. Any ideas on what the cause may be or how I can trouble shoot? Doesnt seem to be a vacuum leak, carb may be running a little rich, seems like plenty of spark and no apparent miss at idle, although at higher throttle it sounds like a miss develops. Thanks for reading. Paul
You don't say what carb it is, but is the accelerator pump working? With the engine off, look down in the carb and pump the throttle, and see if you see gas shoot in. Is the timing right and is the advance hooked up and working?
Some one might help a little better if you said Make,Model,size eng..some detail to know what we're tryin to help with..
Ask "GRITS" about timing he could probably tell something about it . Watched a video filmed by his wife I believe the ***le was" Oh honey your hair". Just a wee bit of a backfire.
Make sure the centrifugal weights in the distributor are working also along with everything they said.
Need more info! If its a sbc, check for a lazy rocker arm (valve covers removed, engine idling). If you find one or more, you need to replace the camshaft, lifters and timing chain/sprocket ***embly. It takes only ONE scrubbed exhaust lobe to make a very gutless chevy. And if the cam is "scrubbed", where did all those metal particles end up? Far too many of them by-p***ed the filter and flowed with the oil right through the bearings. Your call!
Edelbrock/holley ? if it was ran out of time for a bit it could be power valve i had that problem on my sbc
Yep, agree. You gotta find the tune set-up parameters and get it to it. Check & set idle mixture, and 'run a timing light over that puppy'.
HEY FNG, this isn't how it's done!!! These guys all jumped in to help you, and you just disappear! Either answer the questions, or at least THANK THEM, and let them know you got it fixed!
Where did he go? I would think, without knowing the abilities of the previous owner, the "rebuilt carb" is suspect. Hook up a vacuum gage. And get to work!
You might give the guy the benefit of the doubt. His first post was yesterday evening. He may not have internet access except in the evening. Lets see if he responds to questions this evening. And stilldreamin, it would be useful to know if the backfire is in the exhaust or through the carburetor. Jon.
First off, Thanks for all your advise. I work second shift and had to pull overtime last night so I wasn't home until 6am today, then had to sleep and run errands for the kids today before I could get back online. I apologize about the lack of info. The car is a 1964 dodge 330, engine is a 318 poly with a 2bbl carb unsure of make atm think it is a rochester everything appears factory. I still need to change the plugs didn't have the socket for these plugs on hand and haven't had time to pick one up yet. I think the timing may be off a little, don't have a timing light anymore so I have had to adjust it by ear. I am thinking a combination of timing, carb tuning is the problem as well but when I started this post my thinking was fuzzy from lack of sleep (lots of overtime lately) so I didn't state all the info I should have plus my wife was nagging at me that it was time to go to work so I was trying to hurry. I will try the plugs, and check the points maybe try and borrow a timing light and get back with you all. I am sure the carb needs some work but I am not a carb guy so it's going to be a challenge adjusting it. Again, thank you all for your input and the online trouble shooting it did help ***ure me I was on the right track.
Oh and backfire is through the carb, only when I punch the throttle slow acceleration no problems but seems to be a slight miss at high rpms. The accelerator pump appears to be working fine as well.
My vote is for timing. Start with the idea that everything is working properly but just out of adjustment before you start tearing into things. Bad timing has a way of disguising itself as a host of other issues ranging from a leaky intake gasket to ignition problems
Those old 318 A engines were notorious for developing sloppy timing chains which would retard your valve timing and kill your low RPM to mid RPM performance.
I snuck on the computer at work tonight so gotta make my reply fast. Thanks so much for the help. i am hoping to get a chance to work on it more this weekend, have been talking to some local gearheads and seems timing is the likely suspect although I think it may just be a touch of all of the above acting up together. As far as the impatience..I'm the last one that should throw stones about that, I'm about as patient as a 2yr old most of the time. Besides, I should have given more info right off the bat(I knew better) was just in a hurry and..well already explained the rest. As soon as I get everything fixed I will post again. Paul
Well, always check, and fix if necessary, the timing before messing with the carb. So I would say you are on the right track to getting it fixed. Try to find a vacuum gauge. Really helps to have one. Sorry to have been impatient. I forget that others may not have the amount of time to be here that I do! Keep us updated (without getting into trouble). edit: man, roadrunner got his post in while I was typing! Kinda makes mine useless. Good stuff there 440roadrunner!
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