come to my rescue.... Skipping...

[Khyron]

O.k.. so here is the long and short, i've been having issues with the Charger skipping and backfiring... this what what i've gone through, earlier this year i was driving the car home and it started to surge, like it was skipping the ignition... I thought my carb finally crapped the bed and got a new one.. the old one was a 750, new one is an 850... so Replaced the plugs because I figured the fouled out but ater 2 times out, the problem came back... this continued to happen, i would make a change, replace the plugs, and after a few times out it would start skipping again... I brought it to a frined after about a month of aggrivation and he saw that the voltage comming out of the MSB box was low, so we replaced everything...

new distributer
Wires
plugs
MDS 6AL box
MSD Blaster 2 coil
Cap
Rotor...


Rebuild the Carb, 4150 series 850 with mecanical secondarys. 82 jets all the way around. 6.5 power valve, 34 squirter... she's running about 19 on the vacuum gadge... I took the charge rout about 4 times, and now the problem is back... when I idle it pop out the exaust.... when I drive the car surges... has power...looses power....had power...looses power.

I removed and inspected all th eplugs. the plugs are clean... as I said, they where new, no burnt crap or anything that shows it to be fouled.

The MSD power is hooked through a 10 gauge wire to a fuse box, then to the ignition relay, then to the battery. Im getting voltage through all points as 12.5 volts... should be more then enough right?

Im at my wits end... WTF is this cars problem?

Motor stats 67 440 bored .030 over
eddie RPM heads
roller rockers
torker 2 single plane intake
lunati .513 lift cam
flat top forges ross racing pistons
eagle crank
skat H beam rods
Idles at 12 degree and it 35 degree total... ignition doesn't seem to jump around at idle.


HELP ME before this freaking thing see's E-bay and I buy a fuel injected new chally! I think I included as much info as i can think of...


BTW: can plugs be fouled if they are spotless?

[mikepmcs]

cam wiped maybe?  IDK just throwing that out there cause you seem to have everything covered.

[Khyron]

i would hope not, it's has maybe...MAYBE 1000 miles on it.... however, going back and reading some other posts from fireman and the rest of u guys... im wondering if maybe a valve isn't right? but they are brand new heads, bought last year in PA... but installed around octomber of last year.... would a valve issue do this? pop out the exaust and kill a cyl? ... i even had it run and pulled plug wires to see if maybe one wasn't firing, you know, listen for a tone change.... didn't help much, just have me one hell of a ZAP once ....

and then, if it was.... why would a plug change stop it.... then it come back. I've put 6 sets of Fing plugs in this so far LOL. Been using autolites for the eddie heads.

[Khyron]

I try to be thorough before posting problems but this one has be stumped.

[b5blue]

12.5 volts is low, 13.5 is more like real world. Battery, is it tested and in tip top shape? What are you running for an alt. could be MSD is getting marginal voltage/amps and your getting a cascade effect, spark weakens, cylinders load up and clear? How/what are you running for a fuel pump? If you feed from battery side (anything) you are stuck feeding when running after alt. output runs through bulkhead in and out and if battery is weak plus your drawing off it (Making Alt think it's even weaker) Get me? I'm trying to think of what you have not so far?  Check connectors and ground straps any all electrical. (Before giving up)

[Khyron]

hmm, o.k.... well the Battery is only about 5 months old... I swap it out under warrenty every year ;-) so it's reading good... The battery is however in the trunk... and it's a high volume mechanical pump...

So I think Im seeing what you are getting at, so maybe I should get some more 10 gauge wire and run it fromt the MSD <located in the front> and hook it directly to the battery? so that Im not at the rest of the systems mercy?

Ohh, Alt is a standard 60 amp, and has been on the last 3 motors, it's runnign great and hasn't been an issue before. This car has always run a MSD box since i've owned it... first upgrade I made.

[Back N Black]

Did you check fuel pump push rod? i had similar problems and the fuel pump push rod was worn with only 700 miles on the new build. I figured it was the high volume pump because it seem really hard to push the pump lever. I changed it out with a stock pump and new rod ans 800 miles later and the rod is GTG.

[Khyron]

hmm, never looked at fuel delivery, fuel was always arounf 7 psi

[Khyron]

I just thought, could it be a volage regulator issue, even if the MSD is hooked directly up to the battery?

[b5blue]

Check here  www.madelectrical.com  for tips, running anything off battery side is not 1st choice in my book, specially from trunk, keep in mind the longer any wire runs the bigger it must be. My old alt. (factory) didn't charge well at idle and the back and forth discharge at idle then recharge above idle overworked everything. If (at idle) you don't have dimming headlights at night or wipers that slow when you turn the heater fan on, your OK then. A battery that young should be fine.     

[BigBlackDodge]

Exorcism!




BBD

[Khyron]

Check here  www.madelectrical.com  for tips, running anything off battery side is not 1st choice in my book, specially from trunk, keep in mind the longer any wire runs the bigger it must be. My old alt. (factory) didn't charge well at idle and the back and forth discharge at idle then recharge above idle overworked everything. If (at idle) you don't have dimming headlights at night or wipers that slow when you turn the heater fan on, your OK then. A battery that young should be fine.     

it's an old mopar. the lights dim, car doesn't charge well at idle. charges while driving.... MSD suggests being hooked directly to the battery though, it's got a built in fuze, so your saying not too?

[Khyron]

no answers? :-(

[TylerCharger69]

With that .513 lift cam.....You state that you are using roller rockers.....Is it a roller cam and lifter set up as well?  And....What ratio of rocker arms?....1.5?....1.6?   And  maybe weak valve springs?   I dunno....I'm just throwing ideas out there because these ingredients arent posted in your original post.    But I have to agree  that 12.5  is NOT optimum  but if it reads that across the board....i dont see that being the problem as you describe it as to be intermittent

[b5blue]

no answers? :-(

My charging issues ended with a 120 amp Denso alt. kit from Mancini, no dimming or other problems anymore. I didn't rewire the car just put it in. I don't know much about your ignition system, I never used MSD. Do a search I posted pics. if interested.

[Khyron]

hydrolic rollers with a 1.6 lift, springs are from lunati and are good for a .600 lift. 12.5 is not running, i'll take a reading with the charger running.

The only think that makes me doubt a valve or spring issue is it doesn't do it when I change the plugs.... im so freaking confused.

[firefighter3931]

What plugs are you using ? This engine has eddy heads right ?

Ideally, i would like to see more initial timing in the 16-18* range at idle and 34-35* total all in by 2500 rpm.


Ron

[Khyron]

Im using Autolite plugs, I can get you the actual part number... I could give her more initial... but she's at 35 total at 2500 - 3000

[firefighter3931]

It seems that the issue corrects itself initially with the plug change then returns.  I'm suspecting a plug issue...either defective or incorrect heat range. I like the NGK BCPR6ES plugs in the e-heads with pump gas compression. These are by far the best plugs for a street motor.


Ron

[Khyron]

I'll be more then happy to buy the new plugs.... but this wasn't ever an issue until earlier this year..... but i'll try anything once, I will get those plugs tommorow.

anything else you can think of for me to do as well?

I can se ethe heat range thing.... but for the defective, 6 sets would need to have been that way... Im hating the car at this point.

[firefighter3931]

It could be many things ; defective cap or rotor, bad ignition wires, reluctor in the dizzy etc....

Run a resistance test on your ignition wires and see what you've got. You should have no more than 250ohms per foot.

keep us up to speed Jason 


Ron

[Khyron]

hmm, new cap and rotor..... brand new wires.... 3rd distributer because i kept thinking I was getting bad ones... see, this is why we're so confused....  I'll run a resistance test to be safe though.


ohh and second carb

[flyinlow]

I agree with Ron on the NGK BCPR6ES plugs. I use them in my eddy heads. Just changed after 15k looked good. ( 446/ E Heads/Lunati 60303)

.

Ignition : put an electrode ( bolt will work) in the coil wire hole in the distributor cap . Hold the coil wire with a grounded and insulated pliers. Hold it against the electrode and have someone start the engine. See how far the ignition will jump. My MSD will jump about 3/4 of an inch with a bright blue spark before the engine dies.
My MSD starts the car while cranking when the voltage has droped to 11.8. When I go to the track I unplug the alternator and the MSD works fine on just the battery (trunk mounted optima).
I run 25* timining at idle / 36* total . I ran 15 * timming before I watched Waynes video and it ran ok that way. If you are running vacuum advance try unplugging it. I had to limit my vacuuum  advance to about 8-10 * to keep from missing/ bucking at light throttle cruising speeds

Fuel: My carter HV street pump wil fill a 2 liter in well under a minute at idle . 8-9 psi ,regualed down to 6psi. Try with the gas cap off or loose.

fuel pump pushrod I had go bad showed up at extended high power settings.

I would think a bad cam or spring would show up with a vacuum gauge. Irratic

Couple ideas anyway   

[ionracer24]

check ur pushrods and valve springs, also did u change the power valve on the carb when u rebuilt it???  those are always likely culprits for back firing, missing etc....

[mhinders]

.... when I drive the car surges... has power...looses power....had power...looses power.

...that sounds to me like a fuel supply problem. Vacuum in the gas tank? Pump not able to supply enough fuel?

I removed and inspected all the plugs. the plugs are clean... as I said, they where new, no burnt crap or anything that shows it to be fouled.

What color were the plugs? Were they kind of white indicating a lean, possibly overheated condition?
Martin

[Khyron]

all good ideas, I have some things to do later for the charger, I will pick up those spark plugs tonight...

Yes the power valves where replaced when the carb was rebuilt, brand new 6.5's

69 Charger, old fuel cap = lots of venting ;-)

hmmm, fuel pump rod.... i'll have to look into that one.

Main problem will be, when I replace the plugs, the problem will go away and I won't be able to test anything else till it happens again LOL

I wall yank the valve covers and check the pushrods and rockers...

Spark plugs are clean as hell, almost look brand new, one or 2 or lightly toastes... nice clean burn.

[ionracer24]

all good ideas, I have some things to do later for the charger, I will pick up those spark plugs tonight...

Yes the power valves where replaced when the carb was rebuilt, brand new 6.5's

69 Charger, old fuel cap = lots of venting ;-)

hmmm, fuel pump rod.... i'll have to look into that one.

Main problem will be, when I replace the plugs, the problem will go away and I won't be able to test anything else till it happens again LOL

I wall yank the valve covers and check the pushrods and rockers...

Spark plugs are clean as hell, almost look brand new, one or 2 or lightly toastes... nice clean burn.

cool! let us know what happens, i love diagnosing engine troubles..vicariously of course  hehe

[flyinlow]

The car runs fine after you change the plugs ... for a while.  What is differrent about new plugs?  If you put a your car on a Sun oscilascope you can see the firing voltage of each plug. New plugs idling run about 5000-8000 volts to jump the gap . Older,but not fouled plugs, take  a little higher voltage ,say 8000-10000.  This is with resistance wires . Voltages go up under load to 15000-20000 .   Any of these volatages can be fired by a stock ignition sytem ,let alone an MSD system. Mixtures at the extremes of the envelope can increase firing voltages. I am not suggesting you run out and buy a Sun scope , but is you ignition system providing a healthy spark all the way to the plugs?

Is you fuel system providing enough quantity to the carb?

[flyinlow]

If the engine runs fine after a plug change, then acts up after you drive it a few times.

The engine is mechnically ok , except for maybe the fuel pump push rod. Wiped cams and bent push rods do not come and go.

[b5blue]

You did so much replacing is why I was thinking some kind of drain adding up to weaken spark. Good Luck!

[Khyron]

I was thinking the same B5... each piece was replaced as a diagnostic measure, then finally as a "F it i'll replace it all" measure

I ordered my new Plugs that where suggested. I bought a bunch of wire and a new voltage regulator. I'm going to re-wire the entire ignition system then change the plugs and replace the voltage regulator with a higher end consistant one. ... yes, I was a sucker and bought the $50 one LOL

[Khyron]

flyinglow.... great information.... I wish I had a way to test the voltage on the plugs.... i suppose i could put my tounge on the end and have someone crank it over ;-)

on a serious note... i'm gonna have to find a way to test that.

[Brock Samson]

 It's cause your heartless, might i suggest you go intercept a train... 

[Khyron]

It's cause your heartless, might i suggest you go intercept a train... 

lmao! the firebird owner a friend of yours? LOL

[Brock Samson]

 no, i think it's just an inexperianced  kid that got carried away after getting popped with some weed, and panicked after closing on a cruiser at 100+ MPH in the fast lane.. and lost it off the shoulder,.. really tragic.
Sorry to read of your persistant problem off the top I'd say a carb going bad but as I read more,.. i really don't have any idea... 
Sure makes me appreciate that mine runs so damn good without much if any attention...

[b5blue]

I know you have a ton invested in new parts, I went into an intermittent no start problem the same way, swapping out 3 different ECU's, checking wires and voltage, finally gave up and bought new engine harness, A688 kit from Don at FBO and bang! Ran so well I had Don set-up a dist for my build just to really get things dialed in (phased, curved, advance and vacuum advance adjusted) and it purrs like a tiger. Mine to ran for many moons with the exact ignition set up and parts, one thing that pissed me off was it would not start and I would put a 15 year old ECU back in and then it would start! I did find problems in the old engine harness/bulkhead area, but ignition was wired separately off a switch. At one point I replaced the old switch and the new one broke! The car is trying to tell you something.......it's not in the nature of the beast to be unreliable.....like every GM I owned.   

[Khyron]

I know you have a ton invested in new parts, I went into an intermittent no start problem the same way, swapping out 3 different ECU's, checking wires and voltage, finally gave up and bought new engine harness, A688 kit from Don at FBO and bang! Ran so well I had Don set-up a dist for my build just to really get things dialed in (phased, curved, advance and vacuum advance adjusted) and it purrs like a tiger. Mine to ran for many moons with the exact ignition set up and parts, one thing that pissed me off was it would not start and I would put a 15 year old ECU back in and then it would start! I did find problems in the old engine harness/bulkhead area, but ignition was wired separately off a switch. At one point I replaced the old switch and the new one broke! The car is trying to tell you something.......it's not in the nature of the beast to be unreliable.....like every GM I owned.   

good point, well, I did take some of your advice ... last night when I was in the garage smoking a cigar I torn out the wiring for the Voltage regulator and all the wires going to the MSD box... I will rewire all of it tonight and mount the MSB box a bit closer to the battery, I started to thing the same as you "Maybe the wire is just old and not performing up to snuff"

Will have an update for you guys tonight or tomorrow. you should see the spaghetti mess of wiring I have to fix LOL

I would buy a new harness, however all my wiring is remounted and all hidden in fenderwalls, under the dash, and I would just have to splice the new one anyways ;-) may as well replace all the wiring one by one

[flyinlow]

Ok , no more voltages..

Put a phillips screwdriver in the plug boot oft a long wire (#7 or #8 plug , this will give you the most resistance). Start the engine and see if the spark will jump 1/2 inch minimum, bright blue spark.

You can run a long plug wire with a plug inserted. duct tape the plug on top of the hood somewhere it can be seen while driving.  Go for a drive after dark in your 7 cylinder car. It will be missing , but should go down the road. If the engine surges or loses power you can see if the ignition  is still firing.

Crude ,but ,effective....

[Khyron]

hehehe funny yet effective ;-) Well, I just got done re-wireing the entire ignition system with new better wire... Installed new voltage regulator, mounted the MSD box in a safe place,,, and ran out of wire 2 foot before compleating LOL

I don't want to splice because.... well, this is what im trying to undo...

I'll update tommorow.... I'll take her for a spin with just teh new voltage regulator and new wire, see if there is a difference... if not.... i "tape the spark plug to the hood" LMAO

I figure 14 gauge wire since the original was thinner...

[b5blue]

Good Luck!   

[Khyron]

O.k.... after a bit of tweeking the skip seems to be gone, I'm gonna re jet the new carb not that she's running right and maybe some better wires.... One of the wires didn't ohm good and skipped.

[b5blue]

Use Firecores! Firefighter (Ron) has them, best I ever used! Very glad you got it! I did a check, "most cars have a working voltage @ 13.5 to 14.8 volts" considered "normal" generally. (For future reference)      

[Khyron]

I need wires tommorow, can I get them tommorow?

[BrianShaughnessy]

I need wires tommorow, can I get them tommorow?

I didn't know you were still having problems Skippy!!!   

You won't get firecores tomorrow...  his trailer was setup just behind the MA booth at the Nats tho.   I meant to get a set for the 5.9 GC but he wasn't quite organized when we chatted on Thursday and I never got back around. 

But they come highly recommended...  just be sure on your lengths that you need.    You got them funky looms and stuff going on.

[Khyron]

well, 2 nights out now an dthe car is running flawless....hope i didn't jinx myself... I believe I will order a set of the firecores then, im running some cheap temp wires now... I was running teh accell 9.5mm wires and was going to get another set of those, but I would rather give the biz to one of our guys, I can loose the funny looms if it means I can run really nice wires.... so they are pre cut or can I gt a set of cut to fit?

[BrianShaughnessy]

so they are pre cut or can I gt a set of cut to fit?

Your choice.      Contact Firefightin Ron or Rick directly on his website:  https://www.customwiresets.com/home.php