cranks with spark and fuel but wont start - I must be missing something

[oldrock]

my son's 72 charger with stock 318 is having a problem I just can't figure out. I am hoping someone will think of something I forgot to check. Here is what is happening.

Car wouldn't start monday so since I am working from home that day I say "no problem son, I will sort it out for you today". Thinking it can't be that tough I start the basic diagnosis stuff. I crank motor and starter working fine but engine doesn't fire although it does sound like it is trying to fire a little. So next thing I check is to see if it has spark. Sparks at coil so I pull rotor cap and all looks good there. Move on to pull a plug and see if plug is sparking which it was. I did notice spark was thick but looked orange instead of blue. Not sure if that is an issue or not since it was a nice wide spark on the bosch super plugs. Next I notice the plug looked wet so I think flooded. I crank the motor with pedal to floor several times and no luck. I go check the plug again and wet again. Humm, I think maybe carb issue so I try tapping with a hammer to see if that will free a stuck needle. Repeat process and no start and plug looks wet again. So next I try pulling and drying off all plugs. Re-install them and crank engine with pedal to floor and still no start. Check plug and wet again. So I break down and take the fuel line off the carb and pull the float needle. No dirt visable so I use air to blow the opening out and re-install. Still no start and plug still wet. So now I am thinking time to pull top of carter 2 barrel carb. Float working fine and fuel level seems fine (half way up). Look around carb and don't see anything jumping out at me. All seems in order, with no clogged jets and accelerator pump shooting a nice strong stream when applied.

So I am stumped at why this thing doesn't run. Any thoughts? I should mention we have changed out pretty much all the ignition items including new starter, rotor, points, capacitor, cap, coil, wires, plugs. Car was running fine for 2-3 weeks after changes were made.

[TylerCharger69]

Ballast resistor....it will crank and fire over...but it won't stay running.....Me thinks  definately ballast resistor

[R2]

Sounds like it is cranking,,,,but not even starting,,,,,,,, ?


sounds like the plugs are fouling out,,,wet,,,,for some reason....

sounds like you have spark,,,,and fuel.........

did you check to see the rotor is where it should be at TDC,,,( ie,,,you didnt skip a timing gear ? ) might want to bring it to TDC,,,and see where the rotor is facing,,(should be facing #1 plug wire on the cap or 180* off from #1),,,,,, (easy to check,,,you need to make sure you have some compression in addition to spark,,and fuel....)

I would try some starter fluid down the carb,,,,and see if this works,,,if the rotor/compression issue look ok........

I have not had much luck just "cleaning" wet plugs,,,,i usually have swapped in a fresh set,,,,,

[oldrock]

thanks for the comments. I did check the rotor to make sure it was alligned correct according to manual. I also did try starting fluid and no go. I didn't try swapping out the plugs but will give that a shot today and see if that helps.

Re ballast resistor... that is one of the few parts we did not change out. If I am getting spark at the plug, could it still be an issue? If so, I can sure go up to the auto shop and see if they carry them in stock and try it. Is there a brand preference on them or just oem style? Over the years I have had to replace alot of the parts on one car or another but never had to change a ballast resistor. I assume it is just a plug and play affair? 

Re compression, I do have a compression tester and haven't done that. I just did the sounds ok test by listening to the starter cranking and it had the normal sounding rhrr, rhrr sound leading me to believe compression is ok. I can go check compression on each cylinder to see if they look ok if the other suggestions don't get it going. 

[R2]

Sounds like you have compression,,,and the rotor sounds ok,,,,,,,

I would try a fresh set of plugs,,,, **

I was more under the impression a bad ballast would result in the car starting,,,but dying when you let off the key

(maybe swap the ballast first,,,quick and easy compared to pulling all the plugs)

wouldnt hurt to keep a spare ballast resisitor around even if it doenst fix the problem.

let us know......

Doug

[oldrock]

ok time for an update... I replaced the ballast and no go. Changed out all plugs and still no go. Went ahead and changed out the fuel filter since I had picked one up and no difference. THe car will try to start when I crank it but won't quite keep running. I checked the manual to confirm each wire is routed to the correct cylinder and that all were attached properly. Also inspected the wires which are all good since they were replaced in the summer.

Do you think a clogged up intake manifold could be causing these problems? I was told a few months ago that it is a common problem for these old engines and since I have checked everything else just wondering if maybe that could be it? Otherwise I can't imagine why if I am getting spark and fuel to the plugs it won't run 

Maybe I need to hook up the compression tester and see if that could be the issue although it sure sounds like it is making compression based on the way the engine sounds when cranking it over. Anything else I should try? This is really stumping me and I hate to take it to a shop but might have to break down and have it towed into one if I can't sort this one out. I really don't want to do that so anyone have any other ideas???

[mikepmcs]

Let's go back to the fact that you have orange spark and not blue spark.  I think you might have a grounding problem(ie not enough juice to fire the gas if that makes sense)  There is a thread very similar to this one somewhere on this site and it turned out to be a bad ground I think.
I'm going to PM Ron to see if he can lend a hand on this one.

[b5blue]

This is a long shot but we use to pop a potato in the exhaust pipe of "someone's" car just to mess with them. I'm not saying look for a potato but could the exhaust be plugged up somehow? (the result of a "tatered" car was it ether would not start or it blew the tater out, ether way it was funny)  Also it could be "super soaked" with fuel now in which case you would need to pull the plugs, disconnect the coil and stop fuel, then crank it over to vent it out, be certain the battery is maintained at full charge to keep spark strong while trying to get the engine started. I've been following this but your doing what I would.  

[R2]

can you swap in another rotor ( do you still have your old one ),,,,

is the cap dry underneath ?,,,, no moisture,,,,,

i agree,,,it sounds like the spark is not hot enough to fire the plugs,,,and keep it running.......

you said you did verify the rotor is facing the right position at TDC on the cap ?

the other thing might be to swap in the old coil,,,,,maybe the coil is going away,,,,

I would try the rotor/cap/coil/coil wire route at this point........( hopefully you have your old stuff there )

[oldrock]

thanks for the help guys. No obstruction in pipe so we can rule that out. I do have the original coil but it was reading over 2 ohms resistance and the new one was at 1ohm so doubt that is the issue. There is no moisture in the rotor cap and visually it looked good but I do have the old one so will try swapping that out since you just to see if it might be the issue. Didn't save the old points or capacitor so can't swap those out but it was running good for weeks after the swap so doesn't seem too likely course you never know. I am starting to think maybe the lack of blue spark could be the issue also. Maybe just not hot enough to get things going. I wonder if just for grins I should hook up the accel super coil off my 69 mustang on there to see what it does? I think it is 50k or something so if any coil will glow the plugs that one would.

[firefighter3931]

It sounds like there's lots of resistance in the ignition system. Pull a plugwire and get the multimeter out....should be less than 100 ohms/ft.

Sometimes it's near impossible to salvage fouled plugs....i would swap in a new set of NGK's and give it a try. A weak ignition system can lead to fouling as well as flooding the engine during multiple attempts to re-start. 

Pull the dipstick and smell it...if there's a strong odor of fuel ; change the oil and filter asap. The last thing you want to do is wash out the cylinder walls and ruin the ring seal.


Ron

[oldrock]

I did go ahead and change out the plugs today so they are new and that didn't solve it. I will check on the plugwires to see if that is an issue tomorrow. I will also check the oil. I checked it a couple days ago and didn't smell a strong gas smell but if that is a possibility, I will sure change it out. We only have a few hundred miles on it since last oil change but I was wanting to switch to a better oil filter anyway after reading frams suck so this would be a good excuse to go ahead and do that.

I am starting to think this one is going to get the better of me 

[69charger440]

I did go ahead and change out the plugs today so they are new and that didn't solve it. I will check on the plugwires to see if that is an issue tomorrow. I will also check the oil. I checked it a couple days ago and didn't smell a strong gas smell but if that is a possibility, I will sure change it out. We only have a few hundred miles on it since last oil change but I was wanting to switch to a better oil filter anyway after reading frams suck so this would be a good excuse to go ahead and do that.

I am starting to think this one is going to get the better of me 

I am still thinking vacuum leak, but Hive_Mind (Another Member) had a similar problem and we took look at the spark plug wires and found some cuts that were making the headers absorb the spark!! Hopefully spark plug wires solve this for you!!! 

[R2]

I am starting to think this one is going to get the better of me

Nope,,,,we gotta figure this out,,,it's killin me,,,lol

hard to see "all" the wires going bad enough to kill it,,,,,, could the coil wire be suspect ?,,,

i would still check the cap/rotor change/ and swap a coil in before calling Capt Hook

[Corellian Corvette]

Wow looks like you're tried a lot. For certain check the resistance of the plug wires. What's strange, is that it was running so I tend not to think that's the problem.

Try this. Put on a thick set of gloves and make sure your battery is charged 

Get a spare spark plug.

First start with the wire plugged into the coil - put the wire close to the cap and you should see it arc. Then, pull out each plug wire. Plug in the spark plug to the wire, and ground it to any piece of metal. Have your son crank the car and check EACH wire for spark. This will tell you definitively if you are getting a spark at the plug. Make sure you see each plug spark. It's possible you have a couple bad wires but this will answer that definitively.

Also - pull the carb. Do you see gas on the bottom? You may be dripping gas out of a well plug

Lastly - take all the vaccum lines off the car and plug them up. Go around the intake manifold and re-torque it just to be on the safe side.

My bet, just by reading this, is that you have a carb leaking gas out of the bottom somehow.

let us know how it works out!

[elacruze]

It sounds like there's lots of resistance in the ignition system. Pull a plugwire and get the multimeter out....should be less than 100 ohms/ft.

Sometimes it's near impossible to salvage fouled plugs....i would swap in a new set of NGK's and give it a try. A weak ignition system can lead to fouling as well as flooding the engine during multiple attempts to re-start. 

Pull the dipstick and smell it...if there's a strong odor of fuel ; change the oil and filter asap. The last thing you want to do is wash out the cylinder walls and ruin the ring seal.


Ron

Don't forget KISS!

If you've wetfouled the plugs, and have a weak spark they will probably fail to fire or short without sparking when under pressure inside the cylinder, which of course you can't see...remove the plugs, crank the engine over for about 10 seconds with them out, replace with new plugs, preferably copper or silver electrodes (less resistence) and verify that your plug wires have low resistance as Ron says.
Oh yeah, number the wires before you take the plugs out so you're sure to get them in the same place...move the wires around so any points of contact with metal that may be shorting to ground are broken also.
That  should get the car running, but won't answer the question why it happened in the first place. Sounds like you have an ignition issue. What system do you have, stock electronic, points, etc? How old are the wires?

[Corellian Corvette]

agree! Also - what coil do you have exactly? Some coils perfer to get a full 12v - specifically the lower resistence ones like the Flamethrower ii / iii that need a full 12v. try bypassing the ballast resistor and running a full 12v at the coil.

CONVERSELY - you could be burning out coils if the ballast is bad. If you're somehow running a full 12v to a coil not designed for it, they will burn up fast.

There is actually a pretty good troubleshooting guide here for Pertronix systems (http://www.pertronix.com/support/tips/default.aspx) read the part about coils.

You say you're running points? Are you sure you have the dwell set properly? too much gap could be a problem (it will act like your timing is all wrong). I'm actually a fan of those electronic converstions - I run them in all my cars no problem. Have you considered trying to install one of those?

[TylerCharger69]

oh...points?....if not the ballast resistor....points may be burned up.......also....as the car turns over.....does it sound normal or does it sort of "gallop"?  Maybe a timing chain issue if that's a symptom

[oldrock]

thanks for all the additional info guys. Gives me lots of things to take a look at today. Maybe a timeline of what we did will be helpful here. We bought the car at the begining of summer and spent all summer restoring it for my son to use as his first car. At that time, we changed plugs, wires, brakes, all fluid change, radiator hoses replaced, etc to get the car inspected as well as body work and a home paint job. My son was still 15 at the time so it wasn't driven yet.

My son didn't start driving it to school daily until a couple months ago. The car was running but had some hesitation off idle so we went ahead and bought a rebuilt 2 barrel carb from summit and installed that along with replacing ignition items including points, rotor, rotor cap and capacitor. At that time I didn't replace the coil or the ballast resistor. Son drove the car to and from school daily for a few weeks with no problems. A few days ago, Josh was driving and said the car started cutting out on him when he accelerated so he drove it home and parked it. When he tried to start it the next morning, it would try to start but would not run.

So that is when all the "fun" started. I am not an expert mechanic by any means but do have a 69 mustang of my own and have tinkered with hotrods for a long time so I do know basic stuff. I have tried everything I can think of and just cant seem to get it going. I will check the items mentioned today and see if maybe one of those is the issue. That comment on the timing chain has me kinda worried. I am sure hoping it isn't a timing chain problem as that would be a pain to change out. I have to run payroll this morning but will go work on the charger after lunch and report back. Thanks for all the help.   

[elacruze]

Son drove the car to and from school daily for a few weeks with no problems. A few days ago, Josh was driving and said the car started cutting out on him when he accelerated so he drove it home and parked it. When he tried to start it the next morning, it would try to start but would not run.

*Ahem*

Be certain the liquid on the plugs is actually gasoline...could very possibly be water or waterED.

Eric

[69charger440]

I did go ahead and change out the plugs today so they are new and that didn't solve it. I will check on the plugwires to see if that is an issue tomorrow. I will also check the oil. I checked it a couple days ago and didn't smell a strong gas smell but if that is a possibility, I will sure change it out. We only have a few hundred miles on it since last oil change but I was wanting to switch to a better oil filter anyway after reading frams suck so this would be a good excuse to go ahead and do that.

I am starting to think this one is going to get the better of me 

I am still thinking vacuum leak, but Hive_Mind (Another Member) had a similar problem and we took look at the spark plug wires and found some cuts that were making the headers absorb the spark!! Hopefully spark plug wires solve this for you!!! 

WRONG POST!!! Sorry!!

[mikepmcs]

I'm still sticking with the weak spark/bad ground theory.  Keep it simple, I can't stress that enough.  It's easy to go off on tangents and get all wound around one idea and it is totally something else not even related. 

[oldrock]

ok time for another update... tried the following things suggested and still no luck 

tried swapping out old dis cap - no change

swapped out old coil - no change

swapped out old coil wire - no change

checked ohms at ballast resistor -was within specs

measured ohms for all plug wires - gradual increase as length goes up so ok

pulled plug early on and was not wet - after cranking a few cycles was wet

looked at wet plug - smelled like gas with slightly oily look

looked at oil - did not see any antifreeze in it

tried cranking with pedal down and with pedal off, tried cranking with choke closed, partially closed and open and always the same. Engine tries to kick at first and then nothing. Interestingly enough, if I wait a few minutes before I crank, the engine does run for a couple seconds when I first crank it. After that, just tries to start and eventually no starting at all.

As a first car, I had to do some coaxing to get the Mrs. to agree to let Josh have an old muscle car. As the cost continues to creep up, I am starting to wonder if I did the right thing. At some point, you have to ask is it smarter to keep changing out things hoping I get it going, take it to a shop who may just waste more money changing things or consider finding a rebuilt moto at a decent price?

I have to say I have never been so stumped on a carb motor. I have had old mustangs since I was 16 and although I have' had plenty of stuff break, never such a hard thing to figure out.

[oldrock]

Oh and forgot to add, I would have checked timing but timing light is at a friends house so going to need to get that to see if maybe timing chain jumped or something weird like that. Thought about moving distrib around today just to see what happened but thought I better wait so I can see if timing changed.

[R2]

Sorry its not working out......

not sure if you mentioned it,,,,,

-did you change the rotor as well ? ( ie swap in the old one ? )

- dumb question,,,but is the batter fully charged ? ( i had this happen once with a weak battery,,,,might be worth throwing it on the battery charger,,,,or checking the connections real well,,,,,or trying "jumping" it while you try and start the Charger,,,, )

again,,,hope it works out....

you'll get it...