Timing issue

[82_k10]

I have a 1982 k10 I recently bought with a 350 sbc. Here recently I had to replace the heads on the truck and with that I changed the headers and got the edelbrock 1406 carb cleaned and vacuum tested. I also changed the cap, rotor, spark plugs, spark plug wires, etc. Now with that I have to set the distributors timing. I have a timing light with a degree set on it so I just put it on 12 and line up the mark on the timing cover to 0. Now when I start it it runs and revs fantastic. But, when I go take it down my driveway, it does fine the first time then I go take it back down for the second time and it starts misfiring and sputtering. Sometimes the motor even dies. I have cleaned the mechanical advance weights and replaced the springs, even put some softer springs and tried it again but still comes out with the same problem. I am plugging the vacuum and doing all things right (at least I think) to set the timing. Really confused on this and thought someone that knew more than me might have a good opinion. Anything helps. Thanks

 

[Hugomartin]

I have a 1982 k10 I recently bought with a 350 sbc. Here recently I had to replace the heads on the truck and with that I changed the headers and got the edelbrock 1406 carb cleaned and vacuum tested. I also changed the cap, rotor, spark plugs, spark plug wires, etc. Now with that I have to set the distributors timing. I have a timing light with a degree set on it so I just put it on 12 and line up the mark on the timing cover to 0. Now when I start it it runs and revs fantastic. But, when I go take it down my driveway, it does fine the first time then I go take it back down for the second time and it starts misfiring and sputtering. Sometimes the motor even dies. I have cleaned the mechanical advance weights and replaced the springs, even put some softer springs and tried it again but still comes out with the same problem. I am plugging the vacuum and doing all things right (at least I think) to set the timing. Really confused on this and thought someone that knew more than me might have a good opinion. Anything helps. Thanks

Try driving it again with the iac plug disconnected. Not sure if ur 1406 has an iac. Someone correct me if this is bad advice but I see no other way to keep these trucks from stalling out at the worst of times wich can cause a wreck!

 

[da_raabi]

No IAC on a carb, that's EFI stuff. Are you sure you are getting constant 12v to the coil? Does it matter if the motor is hot or cold? How hacked up is the wiring? All sensors and stuff still in place? Emissions stuff?

 

[Bextreme04]

Could be a fueling issue too. Did you reset the idle mixture screws on the 1406 for the new parts? Did you make sure the float level is correct and not getting stuck open?

 

[82_k10]

Could be a fueling issue too. Did you reset the idle mixture screws on the 1406 for the new parts? Did you make sure the float level is correct and not getting stuck open?

I have not touched the idle screws or anything. When the carb was cleaned he also put it on a motor and tuned it . Now thinking about it I might need to do it myself on my motor.

 

[82_k10]

No IAC on a carb, that's EFI stuff. Are you sure you are getting constant 12v to the coil? Does it matter if the motor is hot or cold? How hacked up is the wiring? All sensors and stuff still in place? Emissions stuff?

I have not checked the volts considering the motor ran fine before the head replacement. Does the same hot or cold. And the wiring is a mess from some previous owner. As I know of there are no emmisions stuff on the motor or if there is it’s not hooked up. Another thing I forgot to add is the motor is open headers and I’m sure that can affect the vacuum with no back pressure but I don’t think that is my problem.

 

[Curt]

Edelbrock has directions exactly how to turn the carb.However,I agree the float could be hanging up or not properly adjusted.So,if that’s the case,any idle adjustments or mixture would be short lived.

Fuel pressure is a issue as well,those carbs run best at about 5 psi.

Until you have the carb close to tuned,setting your timing would be a challenge.10 deg BTDC is a good starting point at 650-700 rpm.IMO

 

[82_k10]

Edelbrock has directions exactly how to turn the carb.However,I agree the float could be hanging up or not properly adjusted.So,if that’s the case,any idle adjustments or mixture would be short lived.

Fuel pressure is a issue as well,those carbs run best at about 5 psi.

Until you have the carb close to tuned,setting your timing would be a challenge.10 deg BTDC is a good starting point at 650-700 rpm.IMO

Thx. I will check on the float. This really didn’t occur to me since it’s a freshly rebuilt carb. I have not tested the fuel pressure but I do know it is pumping quite a bit so I will check that also.

 

[82_k10]

Update on the truck. Checked the distributor it has a constant 12 volts. Now I can’t even get it to run good with 12 degrees advance so I’ll be checking with that carb here hopefully in the next few days.

 

[82_k10]

Also forgot to mention the timing mark is jumping a little bit around the timing plate. Also confusing me very much thinking about just buying me a new distributor and carb.

 

[squarelyfe]

Have you pulled any spark plugs to see if they are black sooot covered or oil wet? Describe the condition when running like crap?

 

[82_k10]

I did pull the spark plugs they were a little wet and very black but I cleaned them up played with the idle screws on my carb and haven’t checked them since.

 

[Octane]

Set timing at 10° and adjust carb mix and idle

 

[squarelyfe]

After you run it for a while pull the same plugs and see if they are wet again. You may be misfiring from too much gas being dumped due to leaking well plugs on the bottom of carb, float sticking open dumping the excess fuel, over rich condition or oil. Can you hear any popping or backfiring in the exhaust?

 

[82_k10]

After you run it for a while pull the same plugs and see if they are wet again. You may be misfiring from too much gas being dumped due to leaking well plugs on the bottom of carb, float sticking open dumping the excess fuel, over rich condition or oil. Can you hear any popping or backfiring in the exhaust?

Yes there is quite a bit of backfiring when revving.