Rough start, rough idle, engine sputter

Engine, transmission, rear-end, driveline, fuel system etc..
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maxmac
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Rough start, rough idle, engine sputter

Post by maxmac »

318 Poly in a '65 Town Wagon

Recently upgraded to electonic ignotion - new distributor, plugs, e-core coil. 7mm Wires.

Process so far:
Reset to TDC and set timing 0 (tried minus 5 and plus 5 but either ran rough or no power) with vacuum disconnected and plugged
Had to reset idle - incremental adjustments to air/idle screws
set idle adjustment screw on carb. Original 2 bbl carb but reuilt last year.

On cold starts, truck sputters and if I give it gas by pumping pedal it will eventually fire. Once it fires and warms up it will idle but will idle rough - either too high or it will fluctuate - rev high then drop and almost stall.

Every time I drive it turns into a test & tune session. What am I missing??? Does this sound like a timing/ignition issue or carburation/fueling issue?

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MadMC63
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Re: Rough start, rough idle, engine sputter

Post by MadMC63 »

You should check you're top dead center. Harmonic balancers spin with age and the mark can be wrong. The way you described the engine performance leads me to believe there is a timing issue. Bring the engine idle speed up to about 1500/2000 and move the distributor in whatever direction to achieve best engine performance. Typically best performance occurs with around 28/30 degrees total advance.
1971 Dodge D100
So what's wrong with setting beneath a single pull string incandescent light bulb writing angry letters?

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MadMC63
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Re: Rough start, rough idle, engine sputter

Post by MadMC63 »

To be more precise, if it were an LA I would think the distributor drive gear was one tooth off.
1971 Dodge D100
So what's wrong with setting beneath a single pull string incandescent light bulb writing angry letters?

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maxmac
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Re: Rough start, rough idle, engine sputter

Post by maxmac »

MadMC63 wrote:You should check you're top dead center. Harmonic balancers spin with age and the mark can be wrong. The way you described the engine performance leads me to believe there is a timing issue. Bring the engine idle speed up to about 1500/2000 and move the distributor in whatever direction to achieve best engine performance. Typically best performance occurs with around 28/30 degrees total advance.
I figured this might be the issue. I've checked TDC twice now.... will do again and verify...

stumblinhorse
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Re: Rough start, rough idle, engine sputter

Post by stumblinhorse »

This could be a number of things. I just changed out everything that you did as well. But I did it one thing at a time and checked it as I went. I would suggest you completely go back to the beginning and start with the a normal running engine with the old dizzy and plug wires etc and leave the new plugs in. Then do a step at a time. Then you are certain what is causing the miss. I did it in these steps. Installed plugs and did timing and made sure it ran fine. Then I Installed the new Dizzy with the old cap and wires and then did timing and made sure it ran fine. Then I swapped the cap and made sure it ran fine, then I did all the wires and did a final timing.

Good luck!
1969 D100 LWB 318 np435
2001 2500 SWB 5.9 Cummins nv5600
2016 3500 SWB 6.7 Cummins 68RFE

PwrWgnDrvr
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Re: Rough start, rough idle, engine sputter

Post by PwrWgnDrvr »

stumblinhorse wrote:This could be a number of things. I just changed out everything that you did as well. But I did it one thing at a time and checked it as I went. I would suggest you completely go back to the beginning and start with the a normal running engine with the old dizzy and plug wires etc and leave the new plugs in. Then do a step at a time. Then you are certain what is causing the miss. I did it in these steps. Installed plugs and did timing and made sure it ran fine. Then I Installed the new Dizzy with the old cap and wires and then did timing and made sure it ran fine. Then I swapped the cap and made sure it ran fine, then I did all the wires and did a final timing.

Good luck!
If it "ran fine" why would u keep changing parts?
Or, if one of the unchanged parts was bad, how could it "run fine"?

stumblinhorse
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Re: Rough start, rough idle, engine sputter

Post by stumblinhorse »

PwrWgnDrvr wrote:
stumblinhorse wrote:This could be a number of things. I just changed out everything that you did as well. But I did it one thing at a time and checked it as I went. I would suggest you completely go back to the beginning and start with the a normal running engine with the old dizzy and plug wires etc and leave the new plugs in. Then do a step at a time. Then you are certain what is causing the miss. I did it in these steps. Installed plugs and did timing and made sure it ran fine. Then I Installed the new Dizzy with the old cap and wires and then did timing and made sure it ran fine. Then I swapped the cap and made sure it ran fine, then I did all the wires and did a final timing.

Good luck!
If it "ran fine" why would u keep changing parts?
Or, if one of the unchanged parts was bad, how could it "run fine"?
I think the OP said he "upgraded" those parts, that means something different to me than they were broke. As with all my posts I only comment on something I have hands on experience doing. And with all advice given on a forum, you get what you pay for.

Good luck @maxmac. I'm out....
1969 D100 LWB 318 np435
2001 2500 SWB 5.9 Cummins nv5600
2016 3500 SWB 6.7 Cummins 68RFE

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