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3 Cylinder misfire after shop work on carburator
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Author:  NilsDavey [ Sat Apr 18, 2009 5:55 pm ]
Post subject:  3 Cylinder misfire after shop work on carburator
Hello everyone.

This is a tragic story and no doubt. After taking my perfectly running Dodge Dart Sport to Jiffy Lube it came out stalling at idle. Presuming it was the carburator which had some worn threads i took it to a local shop to get a new one fitted. Sadly the Holly Reman i bought from Autozone was defective and overflooded. The second carb was a Reman Champion which had faulty threads on the fuel line.

So they put the old carb on and i changed out the distributor. Only now the engine is misfiring on 3 cylinders. I've checked the electrical leads and changed out the sparkplugs on the three misfiring cylinders but its still misfiring.

Anyone got any idea where i go from here? Any and all help appreciated. I've got to pick my girlfriend up from the airport on Wednesday and i'd like to do it in a car rather than on the bus.

Thanks in advance!
Author:  ceej [ Sat Apr 18, 2009 6:05 pm ]
Post subject: 
Check your firing order. You may have crossed some wires.

CJ
Author:  SlantSixDan [ Sat Apr 18, 2009 6:40 pm ]
Post subject:  Re: 3 Cylinder misfire after shop work on carburator
Quote:
Hello everyone.
Hi there. Welcome on the board. Go get these three books as quickly as you can and start reading.
Quote:
After taking my perfectly running Dodge Dart Sport to Jiffy Lube
Oops…that was an error. Those quicky oil change places not only tend to use low-quality filters, but they are notorious for fouling things up, often seriously, as for example by under- or over-torquing the oil drain plug. Many engines have been cooked this way. The kids who work there have trouble reliably doing even the simple stuff, even on the current-model cars they kinda know a little about, let alone on a car made before any of them was born. If you can't or don't want to change your own oil, have a real mechanic do it for you; it may cost more upfront but the long-term savings are enormous.
Quote:
it came out stalling at idle. Presuming it was the carburator which had some worn threads i took it to a local shop to get a new one fitted. Sadly the Holly Reman i bought from Autozone was defective
Ouch…you are really going thru the school of hard knocks here, learning what not to do by doing it. :-( "Remanufactured" parts are junk, and this is most especially true of carburetors. If your original is not rebuildable (and/or you no longer have it), give yourself a fighting chance of having the car run well; fit a new carburetor. They're harder to find, but not especially costly compared to "reman" junk. You don't say what year your Dart Sport is; I may have a new carb for it on the shelf — send me a PM if you like.
Quote:
So they put the old carb on
Oh, good, you've got the original (assuming it is the original and not an earlier "reman"). Carburetor operation and repair manuals (and some training movies) are posted here for free download.
Quote:
i changed out the distributor.
Okeh…why? What indication was the car giving that it needed a replacement distributor? Won't-idle problems are usually related more to carburetion or valve adjustment rather than ignition.
Quote:
Only now the engine is misfiring on 3 cylinders. I've checked the electrical leads and changed out the sparkplugs on the three misfiring cylinders but its still misfiring.
On which three cylinders?

Tune-up parts and technique suggestions in this thread, and don't forget these engines require periodic valve adjustment.
Author:  NilsDavey [ Sat Apr 18, 2009 6:48 pm ]
Post subject: 
Hey thanks for getting back so quick.

Changed the distributor because after the shop (not jiffy lube but the place that was installing the carburator) worked on the car the chap suggested it could be the distributor as already one or more cylinders were misfiring (although they werent before he dicked with the carburator).

My sport is a '74. The carb seems pretty ok just some worn bolts that can make it loose.

I've checked the firing order already today but i was stressed so i'll check it again tomorrow. I'll read into valve adjustment etc. Thanks again. Will probably write more of my woes tomorrow.
Author:  NilsDavey [ Sat Apr 18, 2009 6:59 pm ]
Post subject: 
Oh sorry and the cylinders that arent running are 6, 4, 3 and possibly 1. ARGH.
Author:  SlantSixDan [ Sat Apr 18, 2009 7:05 pm ]
Post subject: 
Don't overlook the possibility of a bad manifold-to-head gasket creating vacuum leaks...
Author:  NilsDavey [ Sat Apr 18, 2009 7:14 pm ]
Post subject: 
i forgot to mention the did a compression test on one of the cylinders that wasnt firing and it came out fine.

In my mind they have 'done' something to the engine that is the cause of the misfiring problem. And JiffyLube 'did' something to the carberator or timing to induce the stalling issue. Its not stalling now but i cant drive a car around thats running on 2-3 cylinders. And im very much an amatuer at this (as you can probably tell!)
Author:  slantzilla [ Sat Apr 18, 2009 7:46 pm ]
Post subject: 
Make sure the wires are in the correct direction. Almost sounds like the order is set up for the wrong rotation. :shock:
Author:  Karasik87 [ Sat Apr 18, 2009 8:25 pm ]
Post subject: 
Jiffy lube did nothing to your carburator. Not saying they are shining examples of auto-mechanicl engineering and repair, but unless some stalwart technician wanted to try and get you to buy an air filter, they went nowhere near your carburator. the only thing i can foresee going wrong at a jiffy lube, is someone reached down from hood attemping to wrench off the filter, and hit/rotated/nudged the distributor.
Author:  Karasik87 [ Sat Apr 18, 2009 8:35 pm ]
Post subject: 
Did you have anything else done at the jiffy lube besides an oil change?
Author:  NilsDavey [ Sun Apr 19, 2009 10:15 am ]
Post subject: 
Just oil change. I ifgured they might have loosend the timing or messed with the distributor by mistake as they were clanging around on that side of the car. But seeing as i've replaced the distributor, rotor, and cap now the problem is the misfire.

I'm about to go out and give it another check. Will report back later.
Author:  sandy in BC [ Sun Apr 19, 2009 10:55 am ]
Post subject: 
I bet Jiffy Lube nudged the timing off while trying to get the filter off. I bet the new dist is not installed correctly.

Are we talking about points or EI distributor?
Author:  NilsDavey [ Sun Apr 19, 2009 2:07 pm ]
Post subject: 
First off: Thanks to everyone for the responses. I appreciate it very much.

Ok so i've been out in the 98º sunshine. Re-worked the spark leads so they are definately in the correct order. Only cylinders 4 and 2 are working.

Can you explain the difference in points / EI to someone who knows nothing? The distributor runs with a rotor that spins around the cap hitting points... so i guess its that?

The guy who installed the distributor suggested that the heads were gone and someone else suggested that the cylinders had seized. I dont have the skills to fix anything inside the engine.

Any clever ideas?

EDIT: Because im about to blow my lid and buy a new car. Which would suck.
Author:  Aggressive Ted [ Sun Apr 19, 2009 2:31 pm ]
Post subject: 
Reading these posts sounds like your getting the run around, folks guessing and not really fixing. With out seeing or hearing your car it is hard to determine what the problem is.......being that you have a 74, if it is stock you shouldn't have points but Electronic Ignition. Bumping the cap during an oil change could have caused some damage when you started it up after the oil change. If the cap was off center the rotor could have hit the cap causing damage to the rotor or the cap or both. So look at the inside of the cap and the tip of the rotor to see if there is any damage. Compare them to the pictures in your repair manual or on the web.

Let us know what you find.
Author:  polara pat [ Sun Apr 19, 2009 2:45 pm ]
Post subject: 
"Just because you're paranoid doesn't mean they're not after you." It sounds like you're getting some ridiculous suggestions from some of the "mechanics" you are dealing with. A seized piston will prevent all the pistons from moving so your motor wouldn't run at all. The guy who suggested that the heads were gone"...I don't even know how to respond to that. There's just one head and where has it gone? How are you determining that those particular cylinders aren't firing? Are you pulling the plugs and grounding the lead to check for spark while cranking? That's how I might do it but it's a two man job unless you do it from under-hood but I don't suggest that at this point. If I had to guess, I would say that your distributor has been put in one tooth out (for starters). It will run like this but really poorly. Just take your time and listen to some of the big brains on this forum. It's 99.9% good advice.
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