318 new carb, stalls
02-24-2009 | 06:22 AM
#1
Guest
Posts: n/a
318 new carb, stalls
Hey guys.
I have a 72 D100 with a 318 and I put a new carb on it a few weeks ago. When its warmish outside (above 60) then it starts no problem. but when it's below 60 its a 15-20 min battle to get it going. If I can get it to idle, as soon as i put it in drive it dies. even when the engine is halfway warmed up.
I should mention it has a manual choke and i've tried it with the choke in all positions. (I generally start all the way out and slowly push it in while I crank to get it started.)
The new carb is a Champion carburator. I think the issue is with the rediculously rigged way in which the carburator meters fuel when the choke is not fully open.
(
I might be able to get pictures later, but it basically has a second iddle screw that hits a piece of metal that looks like almost half a pie. and when the choke is pushed in, more of the curve is turned, so this pushes the throttle out further adding gas. Its like something off an old british car...)
Anyways anyone with any advise (Including return the carb, cause I'm thinking that might be the way to go.) I would greatly appreciate it.
Thanks!
-Brandon
I have a 72 D100 with a 318 and I put a new carb on it a few weeks ago. When its warmish outside (above 60) then it starts no problem. but when it's below 60 its a 15-20 min battle to get it going. If I can get it to idle, as soon as i put it in drive it dies. even when the engine is halfway warmed up.
I should mention it has a manual choke and i've tried it with the choke in all positions. (I generally start all the way out and slowly push it in while I crank to get it started.)
The new carb is a Champion carburator. I think the issue is with the rediculously rigged way in which the carburator meters fuel when the choke is not fully open.
(
I might be able to get pictures later, but it basically has a second iddle screw that hits a piece of metal that looks like almost half a pie. and when the choke is pushed in, more of the curve is turned, so this pushes the throttle out further adding gas. Its like something off an old british car...)
Anyways anyone with any advise (Including return the carb, cause I'm thinking that might be the way to go.) I would greatly appreciate it.
Thanks!
-Brandon
02-24-2009 | 06:29 AM
#2
Admin
Joined: Apr 2008
Posts: 8,173
Likes: 200
From: Goffstown, NH
Welcome to the forum.
Why did you replace the carb that was on there? What size carb is it? How many barrels? Anything else done to the motor?
We will need a little more info and pics a re a plus.
It sounds like the idle is too low, the timing is off and the carb need to be adjusted. You will probably have to adjust the timing and mixture screws multiple times before you get it close to being good.
Why did you replace the carb that was on there? What size carb is it? How many barrels? Anything else done to the motor?
We will need a little more info and pics a re a plus.
It sounds like the idle is too low, the timing is off and the carb need to be adjusted. You will probably have to adjust the timing and mixture screws multiple times before you get it close to being good.
02-24-2009 | 08:00 AM
#3
Guest
Posts: n/a
Well, I replaced the old carb because there was play in several of the shafts and I was told by an old mechanic (who seemed to know such things) that a rebuild kit would not do, that I would need to replace the carb if I ever wanted it to stay adjusted correctly. So that's why I replaced it.
Its a 2 barreled carb, as was the original. There is nothing really done to the motor. The truck has 300k mi on it and I'm not sure how long ago a rebuild was done, if at all. Its ball of grease, but doesn't really leak too much oil, and when I changed the oil, I didn't smell any burnt gas/oil leading me to believe that the rings/valves are ok. I know the water pump was done at some point because of the red rtv squishing out, and I assume that the timing belt was done at the same time.
The distributor seems a bit odd though. I tried to check the timing, but I couldn't seem to find the mark with a timing light (leading me to believe its off quite a bit, but maybe I'm doing something wrong. I don't have a ton of experience with these old beasts, though I have set the timing on other vehicles without a hitch.)
I know the previous owner messed with the distributor because he told me he sanded off the corrosion on the points.
Could he have put it in 180 out and then just wired it up so that it would run? seems like that would work, but complete mess up timing adjustments.
I will try and get some pics at lunch.
Its a 2 barreled carb, as was the original. There is nothing really done to the motor. The truck has 300k mi on it and I'm not sure how long ago a rebuild was done, if at all. Its ball of grease, but doesn't really leak too much oil, and when I changed the oil, I didn't smell any burnt gas/oil leading me to believe that the rings/valves are ok. I know the water pump was done at some point because of the red rtv squishing out, and I assume that the timing belt was done at the same time.
The distributor seems a bit odd though. I tried to check the timing, but I couldn't seem to find the mark with a timing light (leading me to believe its off quite a bit, but maybe I'm doing something wrong. I don't have a ton of experience with these old beasts, though I have set the timing on other vehicles without a hitch.)
I know the previous owner messed with the distributor because he told me he sanded off the corrosion on the points.
Could he have put it in 180 out and then just wired it up so that it would run? seems like that would work, but complete mess up timing adjustments.
I will try and get some pics at lunch.
02-24-2009 | 08:39 AM
#4
Admin
Joined: Apr 2008
Posts: 8,173
Likes: 200
From: Goffstown, NH
If the Dizzy was out 180 then it wouldn't run at all.
It sounds like you just need to adjust the timing and mixture screws all at once (If you adjust one then you will have to adjust the other).
The way I like to start of with a new carb is to set the screws all the way in and then back them out 1.5 turns. That is usually a good starting point. Next you will want to watch the RPMs as you adjust both (assuming you have two) mixture screws. The RPM will go up as you let more gas in and go down as you let less gas in. Somewhere in there the RPMs will stop going up (should be around 750 RPM when fully warm).
After that you will want to play with your timing. The timing marks should be in the harmonic balancer. You may have to just clean yours really good to see them. I'm sure someone will pipe in as to what the timing should be cuz I can't recall off the top of my head.
After you get the timing just right, take it out for a spin. See how the motor acts. You will probably have to adjust the timing and mixture screws some and keep retest driving.
It sounds like you just need to adjust the timing and mixture screws all at once (If you adjust one then you will have to adjust the other).
The way I like to start of with a new carb is to set the screws all the way in and then back them out 1.5 turns. That is usually a good starting point. Next you will want to watch the RPMs as you adjust both (assuming you have two) mixture screws. The RPM will go up as you let more gas in and go down as you let less gas in. Somewhere in there the RPMs will stop going up (should be around 750 RPM when fully warm).
After that you will want to play with your timing. The timing marks should be in the harmonic balancer. You may have to just clean yours really good to see them. I'm sure someone will pipe in as to what the timing should be cuz I can't recall off the top of my head.
After you get the timing just right, take it out for a spin. See how the motor acts. You will probably have to adjust the timing and mixture screws some and keep retest driving.
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