Sputtering Question

[NC Rover]

What causes a vehicle to keep wanting to run even after you have turned it off? I keep having to stall the rover to get it to cut off. Now, there are a few items adding to this problem.

1.) Carb has not been thoroughly cleaned...even though it looks pretty clean.
2.) Exhaust has a leak somewhere underneath
3.) Would the timing be off?

When the rover runs, it seems to drive fine...however I have to keep the choke pulled out just a little bit for it to run smoothly.

Also the exhaust gets the occasional pop and sputter while idling.

The spark plugs are new and gaped properly. The plug wires are also new. Fuel is clean and a can of Seafoam has run through the tank.
With that said, would you think this is a timing issue or just a mix of air getting into the exhaust and a dirty carb that has not been tuned properly?

[Les Parker]

NCR,

What dist. and carb do you have.
There is avail for the Weber 34ICH and Zenith 36IV, a fuel shut-off solenoid, that generally deters "running-on" or "deiseling"

[Daurie]

What is your idle set at? If I idle mine up much higher than 750 it tends to run-on. What carb are you running?

I also have a slight pop/sputter on idle that seems to come and go. If I advance my timing it worsens. I have my timing set around 3deg advance which seems fine and the pop seems to have all but dissapeared. My theory on the pop (mine anyway) is it's a valve problem. Maybe a stick valve that doesn't seat perfectly. I don't get too worked up over it as the engine runs fine and has good power. One day I will pull the head and look things over.

[thixon]

Run on is usually caused having the timing advanced too far.

[sven]

Run on is usually caused having the timing advanced too far.

I agree, Ive had this happen to me too. Also check for exhaust manifold leaks,

[NC Rover]

What is your idle set at? If I idle mine up much higher than 750 it tends to run-on. What carb are you running?

Not sure what the idle is set at. I wouldn't know how to find that out. It is a Weber Carb and a Lucas Distributor.

Maybe my timing is off.

[NC Rover]

NCR,

What dist. and carb do you have.
There is avail for the Weber 34ICH and Zenith 36IV, a fuel shut-off solenoid, that generally deters "running-on" or "deiseling"

I have a Lucas distributor and a Weber carb. I'll take some pics and post them up.

[gambrinus]

Tweek your timing back just a touch. Loosen your dist, and turn it maybe 1/16th of a turn. See if that helps. Go another 1/16th and try again. How rich are you running?


RW

[Momo]

Exhaust has a leak somewhere underneath.

There's the probable source of your pop and sputter, and backfiring on deceleration if you have any. Tighten up all your exhaust system bolts.

Could be ign as gambrinus said, fiddle with it a bit at a time.

Also, your run-on can be caused by low octane gasoline, too, though I doubt
it would affect you 2.25 even if it's been decked to a higher compression ratio.

This stuff is kind of fun to trouble shoot, what with tweaking your mixture, idle, ign advance, etc. Trick is to find the spot where it starts with ease, idles smooth, has power, and doesn't backfire, ping or run-on. Sometime it takes awhile...hope you like the view under the hood...

[4flattires]

Run-on by dieseling is caused by fuel in engine igniting without spark.

A good 5 minute read. I agree with 95% of this.

http://mgaguru.com/mgtech/engine/ro101.htm

Jeff

[NC Rover]

There's the probable source of your pop and sputter, and backfiring on deceleration if you have any. Tighten up all your exhaust system bolts.

Could be ign as gambrinus said, fiddle with it a bit at a time.

Also, your run-on can be caused by low octane gasoline, too, though I doubt
it would affect you 2.25 even if it's been decked to a higher compression ratio.

This stuff is kind of fun to trouble shoot, what with tweaking your mixture, idle, ign advance, etc. Trick is to find the spot where it starts with ease, idles smooth, has power, and doesn't backfire, ping or run-on. Sometime it takes awhile...hope you like the view under the hood...

Thanks for the info. I turned the idle back just a hair and tightened the exhaust bolts. No luck. I always use premium gas so thats not it.

I'll see if I can turn the distributer back just a bit. I have no idea if its running lean or not. There is no white smoke (or any smoke for that matter) coming from the exhaust. The tightened exhaust bolts helped a bit with the backfiring but I believe I need new exhaust gaskets.

[thixon]

A good 5 minute read. I agree with 95% of this.

http://mgaguru.com/mgtech/engine/ro101.htm

Jeff

Great link, and good info.

After reading it, it reminded me of an MGB I had that would diesel like there was no tomorrow. I could'nt fix it no matter what I did. Finally, I ended up pulling the head to have it rebuilt. There was buildup all over the valves. After the rebuild, it ran great. Could have been hot spots due to the buildup.

If you cant fix it by adjusting timing, fuel mixture, etc., you could always buy a new head gasket, yank the head for inspection and de-coke if its nasty in there. You'd also get a chance to see whats in there!