backfires when i try to get after it.

83StangSGT(P)

Member

Oct 12, 2009

48

0

6

Upstate NY

Apr 8, 2013

#1

• Apr 8, 2013

• #1

i have an 83 gt i bored 60 over and put gt 40 3 bar heads on it. Has Edelbrock 650 thunder series carb, lunati voodoo cam shaft smallest one. summit racing sold me a kit u cant order any more. drove for a couple years awesome no issues. Starts and idles beautifully. revs right up fine not moving to red line easy. i took it out on its maiden spring voyage. new plugs motor craft platinum plugs. brand new msd wires and rotor. has msd rtr pro billet dis and coil set at 12 to 15 degrees ive tried. driving easy no issues. i try to punch it in any gear 3/4 to full throttle around any rpm and it looses power and backfires. get right out of it and go back cruising im good. i walked it up to about 4500 to 4800 and it takes it. what condition is this. my Edelbrock owners manual seems very generic.

 

83StangSGT(P)

Member

Oct 12, 2009

48

0

6

Upstate NY

Apr 8, 2013

#2

• Apr 8, 2013

• #2

.

 

M

mr2gq

Member

Jun 16, 2011

65

2

7

stockbridge ga

Apr 8, 2013

#3

• Apr 8, 2013

• #3

Sounds like your ignition is breaking up under a load. What's you battery voltage? Mine started doing the exact same thing when the alternator took a dump and it was running off just the battery. But then again mine is fuel injected

 

jrichker

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Apr 9, 2013

#4

• Apr 9, 2013

• #4

If you still have a working stock distributor, put it back in place of the MSD distributor.

 

88LX5.Oh

15 Year Member

Dec 30, 2011

1,442

204

94

Arkansas

Apr 9, 2013

#5

• Apr 9, 2013

• #5

Possibly could be having an issue with the vacuum advance portion of the distributor?

I had a buddy with an MSD distributor and he was constantly having issues with it. I would do what JR said and swap it out for a stock one

 

Noobz347

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Jan 4, 1985

42,941

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Apr 9, 2013

#6

• Apr 9, 2013

• #6

Try JR's advice first.

Open your hood at night and check for arching. Look at the plugs for burned electrodes and gap. Make sure you're running Autolites and not some "oh so kewl platinum" messes or other gadget type spark plug.

 

83StangSGT(P)

Member

Oct 12, 2009

48

0

6

Upstate NY

Apr 10, 2013

#7

• Apr 10, 2013

• #7

I just dug out my old distributor. Would it work with my 6al box? I couldn't see any arching at night. Plugs are motor craft stock replacement for 93 cobra. doubled checked all gaps were.054. Ill swap out asap and let everyone know how i make out. i appreciate the help.

 

83StangSGT(P)

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Oct 12, 2009

48

0

6

Upstate NY

Apr 10, 2013

#8

• Apr 10, 2013

• #8

I have my mint stock distributor (has very minor corrosion on reluctor paddle ill emery cloth clean) in front of me and its a three wire triangle plug. My msd is also three wire strait plug. could i cut the msd plug and install on my stock one. I had the car built while i was in iraq in 06 so im learning as issues pop up. i cant figure out if my old mechanic had to re wire my car when i swapped to the msd or just cut the old plug. Im color blind so im very cautious about wiring. set it on fire once burned out some in line fuses back in 08. Is there any wiring differences between my old one and the pn 8352 msd. I dont have the stock dura spark box on the fender. What would i have to do use my stock distributor. my current wiring for pn 8352 set up is figure 12. http://www.msdignition.com/WorkArea/DownloadAsset.aspx?id=15032386255. Again i truly appreciate all the help.

 

f8tlfiveo

My wife likes my spool and blow-off valve.

Aug 8, 2007

1,585

102

64

Lancaster, PA

Apr 11, 2013

#9

• Apr 11, 2013

• #9

I had this issue when I put the p heads on.. Spark plugs wires were arcing off the headers. You could rev the motor fine. But when you put a load on it, it would sputter

 

83StangSGT(P)

Member

Oct 12, 2009

48

0

6

Upstate NY

Apr 12, 2013

#10

• Apr 12, 2013

• #10

I have doubled checked all my wiring. it was RF interference from my pick up being 6in away from a power source. I tried to clean up my engine bay over the winter. Guess its back to the mess until i can afford the shielded harness. I appreciate all the help

 

jrichker

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Apr 12, 2013

#11

• Apr 12, 2013

• #11

Good find!
Shielding braid is available at electronics parts supply. It can expand 3 - 4 times its inner ID and shrink back down just by pushing and pulling on the braid. You may find that it will slide over the connectors and then shrink back down. If the connectors have removable pins, then it's very easy to do. Just remove the pins from the connector shell, slide the braid on and put the pins back in the connector shell. Only ground one end of the braid to avoid ground loop problems.



I came us with this place by Googling shielded braid...
http://www.daburn.com/2355tinnedcoppershieldingflatbraid.aspx