OK from the beginning. I bought a 67 barracuda original 273 car now has a 360 with supposed 10:1 compression and the Mopar perf. 509 lift hydraulic cam performer intake and holley 3310 750 carb.. The engine I'm told is fresh and it appears to be. I had the car running decent but I wanted to upgrade the distributor which is a single point I believe to be from the 273 engine. I bought a proform electronic conversion kit from Summit. I installed it and the car would not run. I swapped out the ECU with one from one of my other cars and it still wouldn't run. I sent the kit back and exchanged it for a rebuilt points distributor. The car would run with the new points distributor but would not idle. The idle would go from 1500 RPM to nothing and just stall. I bought a Petronix ignitor and installed it in this rebuilt distributor but had the same problem. The car will not idle correctly. I tore this distributor apart and even though it was rebuilt the advance springs were stretched so I replaced them but it did not help. Today I took the entire electronic ignition off my 73 340 Cuda and installed it on the 67. It is a mopar kit with the orange box and I used an extra 4 pin harness I had in stock and wired it correctly.I also used the coil from the 73 Cuda. The car ran but still would not idle. If I crank the idle up to about 2000rpm it will run but lower than that it just stalls. I put on a different carb and there was no change. The engine has low vacuum at idle (I assume from the cam) so I tried a 3.5 power valve, a 2.5 power valve and even a block off plug none of which helped. I did a compression check and a leak down test and all was good but the car would not idle. If I get it to idle for a minute as soon as I rev it the idle either stays high or comes down too low. I started thinking maybe the camshaft is installed incorrectly or something else internal was drastically wrong.. As a last resort I stuck the original points distributor (which now has the new points and condensor from the rebuilt distributor that were removed to install the ignitor) back in the car and it idles fine. Does anyone have a clue why no other distibutor will work in this car?
Can anyone figure this out
- Thread starter 500duster
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66plyValiant
Well-Known Member
check the engine vacuum, it should be 16-22 inches of mercury at idle, (possibly lower with a hot cam) but it should be a fairly constant vacuum signal, something makes me think you may have a vacuum leak creating a leak condition. also check the spark plugs to see what color they are. Kinda wierd it only runs with a points distributor. when you wired it to electronic ignition was it wired like the diagram below?
rtse440
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I also think you have a vacuum leak. Do you have power brakes? If so plug the vacuum port on the intake. Try plugging your PVC port also. The next thing I would do is get the engine running, get yourself a propane torch do not light it open the valve a little and move it around your intake, carb. base. If the engine idle changes you have a vacuum leak .
ignition was wired just like in the diagram. I just took it for about a 20 mile drive with the original points distributor in it. It surges at cruising speed, has a little bit of a dead spot off idle. I stood on it from a dead spot and it is a real pig off the line. I don't have a tach in the car but after about 3000rpm or so it starts to pull pretty good. It idled fine at every stop I made. I let it idle for awhile after I pulled it in the garage and it idled fine. I checked the vacuum earlier when I had the electronic ignition in it. It would not idle well but the vacuum gauge would go from 7 inches down to zero. When I would rev it a little the gauge would jump right up. I'll check it again tomorrow now that it idles with the original distributor.
harvenator
A fish called Wanda
I agree about the leak and also had dizzy problems. 2 new Cardone dizzys from Autozone, a used dizzy from a running 318, a used dizzy from a 340. I finally tried a new Pertronics setup my friend had and no problems at all. I've ordered a new Proform dizzy.
Seems as if there are a lot of shitty dizzys out there, both used and new.
Seems as if there are a lot of shitty dizzys out there, both used and new.
demon seed
The Original Demon Seed
What's your battery voltage, when switching over from the points ignition to orange box or eqivalent you needed to change over to the new regulator and bring your battery up from 12.5/13 to 14.5 volts. A higher voltage on the primary of the coil will give you a hotter spark also.
Yes with that .509 MP cam 6-7 inches of vacuum at idle is about right so you can usually forget about power brakes.
Yes with that .509 MP cam 6-7 inches of vacuum at idle is about right so you can usually forget about power brakes.
I just completed a major wiring upgrade in my 67 for the same reason(s). If you look at the factory wiring diagram you'll find a blue w/white tracer starting at the ignition switch. It is actually 2 very small wires in one female terminal. One of them goes directly to the instrument panels round connector and ends there so its of no help.or hinder. The other goes through the bulkhead and on to the ignition / ballast resistor.
Later models having 60 amp alternators and electronic ignition also got a much larger gauge of wire in this and some other circuits.
To install a larger wire is one option but passing more current through that 40+ yr old ignition switch may shorten its life.
To install a relay is a safer bet.
I did both larger wire and relay for reasons not related to your car.
Later models having 60 amp alternators and electronic ignition also got a much larger gauge of wire in this and some other circuits.
To install a larger wire is one option but passing more current through that 40+ yr old ignition switch may shorten its life.
To install a relay is a safer bet.
I did both larger wire and relay for reasons not related to your car.
I'm still not sure why this engine will only run with the original points distributor but it was kind of a good thing it was acting up as it caused me to investigate further. I had some responses as to a vacuum leak so i checked for leaks from on top of the intake and found nothing so I dug further. I pulled the engine to find the previous owner who had just put the motor in installed it on 1 broken motor mount and the other mount had the nut on about 1/2 turn and the nut was cross threaded. If the motor would have made any power it would have come through the hood. The intake was leaking from underneath and sucking oil into the intake ports. The cam was 4 degrees retarded. I figured i had better pull the pan and when i did it was a real mess. There was metal shavings an inch deep around the drain plug. I pulled the main caps and looked at the bearings and I have never seen anything like it. They are smashed and smeered and flaking and peeling and scored. I don't know if the wrong bearings were installed or what happened. I didn't even bother to put a micrometer on the crank as it is junk. The motor was already .060 over so I pulled the new pistons and the cam out, marked the lifters as to which lobe they were on and i'm going to scrap the rest. The heads are J heads with bigger valves but i don't trust them without being checked out. I was able to find a fresh 360 locally yesterday. I tore it down as I'm not very trusting any more and everything looks good with this new engine although it is lower compression with a milder cam. I'm anxious to see if this engine runs with a different distributor. I hope to have it in this coming weekend.
I just went through this and explained this in another thread. Ill see if I can fnd it and paste it
I posted this before for someone.... 15 initial 36 total Max 38 any more then that you causing damage. Do you know that before top dead center is the plug firing before the piston reaches the top on firing stroke. If you install a bigger cam do not use the vacuum advance. Here is the cheap way to get it close enough for a driver. Take the distributor apart .Weld the advance slots shut toward the insde or the shaft, this to achieve proper rpm total. The slots are .470 factory close them up and file them open to .370 Take out the big spring on one weight and leave the small one on the other . this is the same as two Mopar Light springs. Now when your initial is at 15 your total should be 35. This gives you 20 retard for start up from 35 total. A motor will run is best a 35 -38 at all times. It just needs the 20 retard to start. MSD digital 6 has this built in so you can lock your distributor at 35-38. Before these new digital ign. You would have your coil hooked to a toggle and turn it on after the starter was ingaged. This would allow the motor to start spinning to eliminate cyl. kick back.when running a locked distributor. The 69 that just left here just had it done the car was like night and day. If you are running a factory cam and all pretaining factory parts and you want economy leave the advance in place. This is for cars with engine mods done. But rember a 4bbl is a 8.5 advance and a 2bbl is an 11.0 its stamped in the arm.
Lock your distributor advance and set the timing at 35 total. Your cam is big enough for start up without initial. wants you see I am right you can go for the 15 initial. The springs only decide what rp the total comes in at. Like I said above The new MSD digital -6 has the initial built in. when I start my duster it fires at 16 degees before top dead center, When the motor exceeds 800 rpms it advances and locks the timing at36 degrees before top dead center. It never drops back down to 16 until it is shut off.
Lock your distributor advance and set the timing at 35 total. Your cam is big enough for start up without initial. wants you see I am right you can go for the 15 initial. The springs only decide what rp the total comes in at. Like I said above The new MSD digital -6 has the initial built in. when I start my duster it fires at 16 degees before top dead center, When the motor exceeds 800 rpms it advances and locks the timing at36 degrees before top dead center. It never drops back down to 16 until it is shut off.
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