Timing or Carb Issues ????

runedawg · 11-30-2004, 12:36 PM

I have a 73 dodge truck with a 318 in it. It has the performance electronic ignition kit, summit street coil, and orange ignition module. Also it has an Edelbrock performer intake wit a Holly 600 4 barrel carb.
The prob im having is that it keeps backfiring through the carb and it tries to stay running when you turn the key off.
What causes this and what is the correct ignition timing for my set up

joe rod · 12-14-2004, 03:39 PM

I don't know mutch about carbs. I do know about timing. Make sure you don't have a wire crossed and in the rite order, and make sure youre timing is on. If you're timing is off or a plugwire is crossed it will backfire.
The correct timing will be on the intake manafold. if it is not it is 1 8 4 3 6 5 7 2. start with #1 cylinder up and if it still backfires you might be half off on the timing.

flntlokr · 10-09-2005, 10:55 AM

I just went thru the half off timing thing. It wouldn't run at all that way. (see the 'Dead Ram' thread) Run-on (dieselling) is usually due to super-rich mix which allows the engine to keep going for a while because the hot combustion chamber will ignite a rich compressed fuel mix without spark. Bad timing will also make it happen (late timing I think) and can also make for carb fires. Stick a vacuum gauge on it to help the diagnosis and tuning. And surely check the firing order just in case.

chevyguy · 10-09-2005, 11:07 PM

Carb cannot cause any of the symptoms described above Sorry flntlokr, But this is a timing issue all the way, backfiring comes from improper ignition timing and dieseling comes from advanced ignition timing. Retard the distribiutor and yes using a vacuum gauge helps, but not required. Simple start the motor and turn the dist counter clockwise until the motor starts to bog down, turn to the center of the 2 positions and tighten it down,If you are unable to find a satisfactory timing setting then i susoect the motor has jumped time and it is time for a new timing belt, or just upgrading to a chevy motor.

fanbladez · 11-05-2005, 02:11 PM

well also backfiring and continueing to sputter after ignition is off could be bad gas i;ve had problems similar and thats what it was but just a guess on my part

chevyguy · 11-05-2005, 04:19 PM

Correct, but very unlikely.Bad gas cannot cause backfiring though, This is a timing issue not a carb issue. Both symptoms point to timing. Is it backfiring thru the carb or thru the exhaust.

Itstali25 · 11-05-2005, 04:20 PM

^ I concur doctor

Truck_Man · 11-17-2005, 02:41 PM

Im thinking the timming is advanced to much.

chevyguy · 11-17-2005, 07:36 PM

Umm the timing would have to be reterdid too much since it is backfiring thru the carb. Advanced would be backfiring thru the exhaust.

HVY84CHVY · 11-18-2005, 05:51 PM

chevy motors, LIKE A ROCK (to chevy guy) willl be around forever

10-09-2005, 11:07 PM	#4
chevyguy Senior Member Join Date: Sep 2005 Location: ALABAMA Posts: 3,370	Carb cannot cause any of the symptoms described above Sorry flntlokr, But this is a timing issue all the way, backfiring comes from improper ignition timing and dieseling comes from advanced ignition timing. Retard the distribiutor and yes using a vacuum gauge helps, but not required. Simple start the motor and turn the dist counter clockwise until the motor starts to bog down, turn to the center of the 2 positions and tighten it down,If you are unable to find a satisfactory timing setting then i susoect the motor has jumped time and it is time for a new timing belt, or just upgrading to a chevy motor. __________________ Friends dont let friends use body lifts USMC 92-96 USCG 98 to present

11-05-2005, 04:19 PM	#6
chevyguy Senior Member Join Date: Sep 2005 Location: ALABAMA Posts: 3,370	Correct, but very unlikely.Bad gas cannot cause backfiring though, This is a timing issue not a carb issue. Both symptoms point to timing. Is it backfiring thru the carb or thru the exhaust. __________________ Friends dont let friends use body lifts USMC 92-96 USCG 98 to present

11-05-2005, 04:20 PM	#7
Itstali25 Senior Member Join Date: Jul 2004 Location: Southern Missouri Posts: 708	^ I concur doctor __________________ http://www.cardomain.com/ride/644045 Trucks are just cars when they grow up!!! If your gunna get a truck....Get a TRUCK!!

11-17-2005, 07:36 PM	#9
chevyguy Senior Member Join Date: Sep 2005 Location: ALABAMA Posts: 3,370	Umm the timing would have to be reterdid too much since it is backfiring thru the carb. Advanced would be backfiring thru the exhaust. __________________ Friends dont let friends use body lifts USMC 92-96 USCG 98 to present

11-18-2005, 05:51 PM	#10
HVY84CHVY Full Member Join Date: Sep 2005 Location: MA Posts: 30	chevy motors, LIKE A ROCK (to chevy guy) willl be around forever Last edited by HVY84CHVY; 11-18-2005 at 06:06 PM.

11-30-2004, 12:36 PM	#1
runedawg Junior Member Join Date: Nov 2004 Posts: 2	Timing or Carb Issues ???? I have a 73 dodge truck with a 318 in it. It has the performance electronic ignition kit, summit street coil, and orange ignition module. Also it has an Edelbrock performer intake wit a Holly 600 4 barrel carb. The prob im having is that it keeps backfiring through the carb and it tries to stay running when you turn the key off. What causes this and what is the correct ignition timing for my set up

12-14-2004, 03:39 PM	#2
joe rod Junior Member Join Date: Dec 2004 Posts: 6	I don't know mutch about carbs. I do know about timing. Make sure you don't have a wire crossed and in the rite order, and make sure youre timing is on. If you're timing is off or a plugwire is crossed it will backfire. The correct timing will be on the intake manafold. if it is not it is 1 8 4 3 6 5 7 2. start with #1 cylinder up and if it still backfires you might be half off on the timing.

10-09-2005, 10:55 AM	#3
flntlokr Full Member Join Date: Sep 2005 Location: Victoria, BC Posts: 10	I just went thru the half off timing thing. It wouldn't run at all that way. (see the 'Dead Ram' thread) Run-on (dieselling) is usually due to super-rich mix which allows the engine to keep going for a while because the hot combustion chamber will ignite a rich compressed fuel mix without spark. Bad timing will also make it happen (late timing I think) and can also make for carb fires. Stick a vacuum gauge on it to help the diagnosis and tuning. And surely check the firing order just in case.

11-05-2005, 02:11 PM	#5
fanbladez Junior Member Join Date: Nov 2005 Posts: 5	well also backfiring and continueing to sputter after ignition is off could be bad gas i;ve had problems similar and thats what it was but just a guess on my part

11-17-2005, 02:41 PM	#8
Truck_Man Senior Member Join Date: Oct 2005 Posts: 213	Im thinking the timming is advanced to much.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
carb problems	F150on40's	Ford Truck Forum	3	01-05-2005 07:52 PM