Hi everyone,. m a new member and was hoping to post a few pics etc today to get me started on the site...Instead, Ive spent my day of trying to get my 68 Polara to run!! I have very basic engine skills but am happy to work on brakes, chassis etc. This one has got me stumped so could do with some informed advice from the experts!
Car has been running lovely until a few days ago. I started her up on the driveway and after running for about 5 seconds, she died instantly. Turned over again and started but big exhaust backfire. I assumed, rightly or wrongly, that this was probably unburned fuel in the cylinders as she had cut out on full choke (auto). I used her for couple of runs the same day but she was sluggish and hesitant and was backfiring a bit. I thought this might be fouled plugs so today, I put a new set in. The old ones were ok, and didn't look fouled. Then started her and again she ran perfectly for about 5 seconds (just enough time to get her out of the garage!!) and died instantly again. Ive checked for fuel to the carb which is ok, swapped the coil and HT lead for my spares but no joy. Turns over fine but no signs of firing. Ive checked as best I can for leaks in carb etc but Im fishing in the dark if Im honest as my skills are limited. I gave in at about 4pm, pushed her back into the garage Im renting and went home to ponder (unsuccessfully!).
I dont mind throwing some money at her for repairs etc as she is a lovely, original car but I don't want to do it blindly.....anyone got any ideas please?? Specs are 383 4bbl, Edelbrock carb, electronic aftermarket ignition, 727, and 8 3/4 rear.
Many thanks and all the best.....Steve
68 Polara starting/ running probs
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68 Polara starting/ running probs
Last edited by Steve on Thu Feb 02, 12 6:05 pm, edited 1 time in total.
Welcome aboard Steve, nice to see you here.
I'm sure you'll get a stack of advice, but my thoughts go straight towards the ignition and seeing if you have a spark and particularly one that arrives at the right time!
If you system is running a condensor annd a ballast resistor, I'd check those out as well, one of our electrical engineers will be along to tell you how...I hope
I'm sure you'll get a stack of advice, but my thoughts go straight towards the ignition and seeing if you have a spark and particularly one that arrives at the right time!
If you system is running a condensor annd a ballast resistor, I'd check those out as well, one of our electrical engineers will be along to tell you how...I hope
Hope you don't have a mechanical voltage regulator as they can cause problems with the electronic ignition , they like a nice smooth voltage which the old type regulator does not give you, change it for an electronic one , also the orange boxes can give up if you don't have a good earth
John Rutledge
when someone is turning it over to start
stick a multimeter set to 20V range between the engine side of tha ballast resistor and earth
see if its about 12 volts
once it starts it should drop to 8 Volts for your 8 volt ballast resistor coil
if its 8 when starting and dropping to 5 or 6 when running
(you might have a problem withe the balast resistor but unlikley...they work or they are burnt out nothing in between)
(less tan 8 volts) the ignition box will struggle and the spark will be marginal.
5-6 volts when running isn't enough voltage to push the 3-4 amps necessary to power coil and run the ignition box
issue will probably be corrosion at
1) bulkhead connector
2) connector for the 4 wires from the ignition switch
3) connectors on the ballast
4) poor connections from earth lead to body and body to battery, if you have bolt on replacement battery clamps that bolt to the wires take em off and clean them and the wire (although this would be evident by sluggish starter or click of death as well)
5) poor earthing of the igntion box
what happens is in damp weather the connectors corrode and get coverd in white or green flour like stuff...which when damp is like a metal salt paste i.e really quite conductive
when we have high pressure and extereme cold like now it promotes really dry conditions all humidity is locked up as ice on the ground
its great for drying the washing but the metal salt i.e corrosion in yer lectrics drys out as well and becomes very none conductive making each connector more resistant
a resistant connector eats the volts up that you need to run the ignition system.
car runs until coil heats up a bit (i.e its resistance increases) then that resistance + any excess caused by dodgy connections pushes it just too far
and parp de parp de parp followed by cutting out followed by pig to start
it will start the next day from cold and fail the same way again just as you get it up the drive
been there and done this recently...morning with the emery cloth and some vasline and all now ok. worse if the car ever in its life lived near the coast, as brass bullet and spade connectors hate salty air and salty air leaves a residue on everything it touches
Dave
stick a multimeter set to 20V range between the engine side of tha ballast resistor and earth
see if its about 12 volts
once it starts it should drop to 8 Volts for your 8 volt ballast resistor coil
if its 8 when starting and dropping to 5 or 6 when running
(you might have a problem withe the balast resistor but unlikley...they work or they are burnt out nothing in between)
(less tan 8 volts) the ignition box will struggle and the spark will be marginal.
5-6 volts when running isn't enough voltage to push the 3-4 amps necessary to power coil and run the ignition box
issue will probably be corrosion at
1) bulkhead connector
2) connector for the 4 wires from the ignition switch
3) connectors on the ballast
4) poor connections from earth lead to body and body to battery, if you have bolt on replacement battery clamps that bolt to the wires take em off and clean them and the wire (although this would be evident by sluggish starter or click of death as well)
5) poor earthing of the igntion box
what happens is in damp weather the connectors corrode and get coverd in white or green flour like stuff...which when damp is like a metal salt paste i.e really quite conductive
when we have high pressure and extereme cold like now it promotes really dry conditions all humidity is locked up as ice on the ground
its great for drying the washing but the metal salt i.e corrosion in yer lectrics drys out as well and becomes very none conductive making each connector more resistant
a resistant connector eats the volts up that you need to run the ignition system.
car runs until coil heats up a bit (i.e its resistance increases) then that resistance + any excess caused by dodgy connections pushes it just too far
and parp de parp de parp followed by cutting out followed by pig to start
it will start the next day from cold and fail the same way again just as you get it up the drive
been there and done this recently...morning with the emery cloth and some vasline and all now ok. worse if the car ever in its life lived near the coast, as brass bullet and spade connectors hate salty air and salty air leaves a residue on everything it touches
Dave
The Greater Knapweed near the Mugwort by the Buckthorn tree is dying
Gents,
Thank you very much for these very practical suggestions!
Ive printed Daves message so I can work methodically through each step as it sounds like you have experienced exactly what I have (except my car stops dead after a few seconds). Im going to clean and examine everything and see how I get on. Ive got some quick release terminals on the battery and Im tempted to get rid of them. Poor earths seem to feature a lot in many problems so will definately check all those. Ballast resistor check sounds easy enough with another set of hands so will crack on with that aswell (wish the car was at home as Im itching to do it!).
One final thing......Ive recently put a new mechanical voltage regulator on in an attempt to cure lights and heater fan getting brighter/ stronger in unison as I drive. Anyone know where I can get an electronic one and is it a 'bolt on' addition?
Im also reading up on the main jet suggestion but am hoping its something easier to deal with as carbs scare the life out of me!!! (at least Im honest!)
Sorry more questions but Im keen to learn from the pros and thank you all again for your advice and suggestions,
Cheers Steve
Thank you very much for these very practical suggestions!
Ive printed Daves message so I can work methodically through each step as it sounds like you have experienced exactly what I have (except my car stops dead after a few seconds). Im going to clean and examine everything and see how I get on. Ive got some quick release terminals on the battery and Im tempted to get rid of them. Poor earths seem to feature a lot in many problems so will definately check all those. Ballast resistor check sounds easy enough with another set of hands so will crack on with that aswell (wish the car was at home as Im itching to do it!).
One final thing......Ive recently put a new mechanical voltage regulator on in an attempt to cure lights and heater fan getting brighter/ stronger in unison as I drive. Anyone know where I can get an electronic one and is it a 'bolt on' addition?
Im also reading up on the main jet suggestion but am hoping its something easier to deal with as carbs scare the life out of me!!! (at least Im honest!)
Sorry more questions but Im keen to learn from the pros and thank you all again for your advice and suggestions,
Cheers Steve
It could be any number of things but it does sound like the ignition timing is way out. A few years my car began running rough and I just about made it home. Checked the timing and it was about 30 degrees retarded. I noticed I could move the relucter on the distributer shaft, the roll pin that holds it to the shaft had broken. Fitted a new roll pin and all was well again.
So the first thing to check is the ignition timing.
So the first thing to check is the ignition timing.
1970 Road Runner, 505CI, 4 speed, GV overdrive, 3.91 gears.
11.98 @ 117mph on street tyres
11.98 @ 117mph on street tyres
-
mopar_mark
- Posts: 6711
- Joined: Fri Jul 14, 06 8:01 pm
- Location: Windlesham, Surrey
Some timing gears have plastic coated gears, if it strip, timing jumps & has had happened to me - quick & cheap check is to pull a rocker cover, make sure motor is on TDC & check to see inlet/exhaust position on No 1 Cylinder
EDIT Ignore that, I didn't see/read the bit about new plugs & running for 5 secs
EDIT Ignore that, I didn't see/read the bit about new plugs & running for 5 secs
"I spent a lot of money on booze, birds and fast cars. The rest I just squandered."
Thanks Mick... Ive got a timing light (never used it though!) so will check that when I work out how to do it without the engine running. Im trying to think logically about it and am guessing I attach it to the battery +/- and number 1 plug lead, ignition on, somehow hand crank till the timing marks line up at 5 deg BTC and see if the light comes on???? (told you Im a novice!) Or can I check with the engine just cranking over without actually running? Suppose would show same as if running just slower strobe relevent to rpm??
Just to add to this, ive found a passage in a 1968 Chrysler Master Technicians Manual that relates to cold weather starting. It says that if the engine starts then stalls in the cold, instead of the usual throttle pedal to the floor then all the way up before start, as in normal weather, push the pedal to the floor then release it halfway and hold instead. Hold there, start then release when engine running smoothly. Never even considered this method.... any thoughts??
Just to add to this, ive found a passage in a 1968 Chrysler Master Technicians Manual that relates to cold weather starting. It says that if the engine starts then stalls in the cold, instead of the usual throttle pedal to the floor then all the way up before start, as in normal weather, push the pedal to the floor then release it halfway and hold instead. Hold there, start then release when engine running smoothly. Never even considered this method.... any thoughts??
Has the engine got spark, if it has, check your fuel pump is working and that you have fuel to the carb, as Mick said, something may have moved or broke to cause the issue.
I had a ballast resistor go once, when i took it off it was broken along the back, it would run for a bit then stop, also check your reluctor gap but dont use steel feeler gauges use brass .006 and .008.
Mick
I had a ballast resistor go once, when i took it off it was broken along the back, it would run for a bit then stop, also check your reluctor gap but dont use steel feeler gauges use brass .006 and .008.
Mick
Got spark for at least few seconds as runs fine and I loosened the fuel pipe at the carb and fuel came out so happy with pump. Got a test to do as per earlier post to check ballast resistor so thats on going. Not sure exactly how to check reluctor gap but will take dist cap off and have a look. Should tell me how in the workshop manual. Going to check for spark after she has cut out tommorrow and check timing. Also going to clean all connections and earths as per advice and see how I get on then.
Cheers....Steve
Cheers....Steve