before the problem this is what i have 1949 dodge coronet, original 230 flathead six with a giromatic thans, still 6 volt its pretty much all original when i am driving it and i hit 20 o 25 miles an hour the car starts pulling back and backfiring like it wants to shut off if i step on it the car pulls back and start slowing down (like when you break with the engine, or when you drive on first and let go of the clutch whitout shifting to another gear) or if i start ****ing with the gas pedal (steping on it and letting it go real fast) the car goes a little faster till about 35 or 40 after that its when it starts backfiring i allready has new fuel pump new spark plugs new spark plug wires rebuilt carburetor new cond., rotor, points changed all the fuel cleaned the gas tank cleaned the fuel line i am runing out of ideas, ive had two mecanics look at it but they dont know about working on old cars anybody knows what i am talking about or has had the same problem any advice or ideas on whats cousing the problem i will REALLY APRECIATE IT THANKS GUYS!!!!!!
are you sure that your timing is correct and that your timing advance is working right? my first thought is that it sounds like you have a timing issue. -scott noteboom
ITS GOING TO SOUND STUPID BUT HOW DO I CHECK IT? ive had a hard time looking for info on the car in the internet i cant even find the timing order
I suggest you also post this question on the forum at www.p15-d24.com The entire membership there is composed of us mopar flathead six lovers, and many of those guys have been around these motors for decades. To me, it sounds like a): your vacuum advance is not working, b): your timing chain has either jumped a tooth, or has stretched badly. c): your cam has become very badly worn. Is this a new problem, or has it slowly got worse? Or was it like this when you got the car? In my opinion, you're wasting your time trying to find a mechanic who knows these things. Much better to spring for a manual off ebay, and start fixing it yourself. That's what hot-rodding is about, and that's what the Hamb is about. BTW; if your car has the original motor, I think it's more likely a 218 than a 230.
kinda sounds like to much air and not enough gas...you said the carb was rebuilt right?.....did you mess with the timming when you changed the the plugs and wires?...i say dont touch the timing if you havnt fooled with it..and adjust your carb....just my 2 cents could be wrong
Sounds to me like the points are incorrectly set. That would change the timing also. Your issue sounds like a higher rpm problem, could also be a fuel supply problem. Not to sound mean, but if you can't find anyone that can work on it, who has done what has been done this far? Get a book, these are about as simple and cars come. Learn how to fix it yourself. Good luck. Gene
1) Make sure your ballast resisor is OK. 2) Make sure your coil is hooked up properly. (positive to positive, etc.) 3) Make sure your fuel filter is clean.
I vote for a timing problem also. I have had cars act like this when the timing was too far advanced. It would run up to a certain RPM but then it would almost start to strangle and under a load it would backfire. The timing was so far advanced that when the advance kicked in it would almost try and run the engine backwards, so to speak. I would try to find out how to time it properly, or at least if nothing else... check the points gap, and then simply set the distributor back a bit and see if it runs any better. You would set the distributor back by rotating it the same direction that the rotor turns. If you have no timing marks you might paint a mark at the distributor base just so you know where you started at, that way you can always put it back if my advice is ****py... Tomo
Check these out...... Vacuum advance cannister is bad- [or the point mounting plate] is sticking and not letting it advance.... Open up that carb and see if there is any ****-dried up gas or contamination blocking a jet..sometimes a "rebuilt " carb has been installed [has had gas in it] then returned to store and the next owner thinks he is the first when it is actually screwed from the dried gas until bowl is cleaned out]
i have done all the work myself the only reason i got the mecanics is becouse a guy told me that it was something serius and that it needed a profesional on those cars
it has had the problem since i got it i read on my friends book that the coronet came with the 230 engine actually i am using tha book to do all the work 1938 to 1953 all makes and models so it has very limited info on my dodge
I read your post and you made no mention of checking the fuel filter. I had a similar problem with my truck going up to Iola this year. Replaced the fuel filter and has been fine since. Just my 2 cents.
I had those symptoms with th wrong points. They bolted in ok but they were in differnt position on the plate and opened with the rotor further around in the cap. when the combination of vacuum and centrifugal advanced the timing the rotor was pointing at the next cylinder's wire in the cap and backfired like a shotgun. I put the old points back in till I could get the right ones, that fixed it. Also start it up in the dark and look for arcing from those 'new" plug wires. That could do it too. I've had brand new wires be bad right out of the "made in China" box.
had a 53 chevy truck... 235 six. it would start right up and idle well. it would also drive well in first gear (3 speed stick) but when I went to second it would pop and not run for ****. did all the stuff people do in these cases. points, check timing, advance all that stuff. took a compression check and had a dead cylinder. so I had a sticking valve, weak spring, or maybe something went down the carb and lodged itself in the valve seat. never found out cuz I sold it before I could get around to fixing it.
I seriously doubt the timing chain has jumped a tooth. It's commonly mentioned, but not commonly seen. Your engine is a 230. I have a '50 Wayfarer with 230/Fluid drive that had a similar problem, but worse- I would rev the engine, in gear or out, to certain rpm, and it would cut out so bad it was like I was "on" the rev limiter in a drag car. Absolutely would not rev past that point no matter how I played the throttle. It ended up being a combo of a shot vac advance, and a sticky mechanical advance. Top that off with the worn out throttle shafts in my dual carbs (vacuum leaks) and I had quite the mess. I always use Standard/Blue Streak brand ignition products.
It sounds to me like someone gave you points for a 12 volt car instead of a 6 volt. Either that or the coil is wrong. I would go for points first they are cheap. Make sure they are properly set. To check the timing there are two ways to do it. 1. use a timing light and unhook the vacuum line from the distributor and plug it. Find the timing mark on the Harmonic Balancer and move the dist until the light flashes with it in just the right spot. 2. Loosen the dist hold down bolt and using one hand to turn the dist. a little at a time and the other hand to quickly accelerate the engine at the carb find the possion of the distributor that allows the fastest acceleration. gumpa
I'm w/ gumpa; points are cheap and easy. When I can't find a spec, I just set 'em to .017 and quit worrying. To check fuel filter: drive the car in a fairly deserted area where you can get it to run funny. Simultaneously turn off the key and put in the clutch, and coast to the side of the road. Unhook the top of the carb, and see how much fuel is in it. Worth a try. You could also check mix by running a propane booster w/ a long hose from the engine compartment. Get a buddy to ride shotgun and try feeding propane while the car acts up. This'll make a lean condition go away (at least while you're feeding the propane...): it'll make a rich condition worse. Ignition timing can be figured w/ a good (dial-back) timing light. That and a vacuum gage will tell you everything you need to know about your spark curve. I've also had an ignition condensor cause weird part-throttle running problems (idle and WOT were okay). BTW, someone mentioned new plug wires being faulty. I had a whole 2 week old set of tune up parts on a '62 beetle years back. Bought it all at schuck's. ****er ran okay until it just refused to start one afternoon, about 30 miles from home. Dad came w/ bosch parts, we swapped 'em out, and volia! Started on first crank. A couple years later, working at honda shop, saw LOTS of cars come in for no-start and driveability w/ 'made in italy' on dist cap. New caps fixed problem. Moral: buy ****ty parts; you'll get better at replacing them! -bill PS: if you need specs, PM or email and I'll look up in manuals for ya.
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