Carb and Idle Problems
#1
Carb and Idle Problems
Hello Everyone,
I finally got my baby running! She's an 84 GSL which I just replaced the engine in (best $250 I ever spent). She's running a little rough and I don't think the secondaries are opening up since it feels under powered and it struggles between 5000 and 6500, wont really go past that. It's a stock carb, stock engine. The carb has had a recent rebuild, per the previous owner, so it's pretty clean. I've taken it apart and can't find any clogs.
I can't get the idle below 1500 without the car dying and the idle will flutter about +/- 100 rpms. When I try to get the idle lower, the engine will shake and run rough. I don't think the mixture is right, so I've been playing with that some and it helps a little, but it isn't smooth. Also, when I'm looking down into the carb, I'm seeing the front barrel pull more gas then the rear. The rear only opens up like the front when I take the rpm up to 3500 or higher.
Anything I can look at for the idle??? I've ventured past my limited knowledge and have run out of ideas.
Also, a wierd timing thing... When I put the timing on the rear plugs, I can see the timing marks and set the timing fine, but when I switch over to the front plugs, I can't see the marks. I made a while mark exactly opposite the timing marks on the pully, and I can see that mark when I time the front plugs. I can't understand what could be causing that. I know both sets are sparking, but I can't know why the fronts are sparking at the wrong time. Please help with this. I'm at a loss here....
Thanks in advance,
Levent
legokcen@bellsouth.net
I finally got my baby running! She's an 84 GSL which I just replaced the engine in (best $250 I ever spent). She's running a little rough and I don't think the secondaries are opening up since it feels under powered and it struggles between 5000 and 6500, wont really go past that. It's a stock carb, stock engine. The carb has had a recent rebuild, per the previous owner, so it's pretty clean. I've taken it apart and can't find any clogs.
I can't get the idle below 1500 without the car dying and the idle will flutter about +/- 100 rpms. When I try to get the idle lower, the engine will shake and run rough. I don't think the mixture is right, so I've been playing with that some and it helps a little, but it isn't smooth. Also, when I'm looking down into the carb, I'm seeing the front barrel pull more gas then the rear. The rear only opens up like the front when I take the rpm up to 3500 or higher.
Anything I can look at for the idle??? I've ventured past my limited knowledge and have run out of ideas.
Also, a wierd timing thing... When I put the timing on the rear plugs, I can see the timing marks and set the timing fine, but when I switch over to the front plugs, I can't see the marks. I made a while mark exactly opposite the timing marks on the pully, and I can see that mark when I time the front plugs. I can't understand what could be causing that. I know both sets are sparking, but I can't know why the fronts are sparking at the wrong time. Please help with this. I'm at a loss here....
Thanks in advance,
Levent
legokcen@bellsouth.net
#3
Senior Member
This could be a multitude of things. Before messing with the mixture too much, I would check for vacuum leaks. There are several threads on this already. Search on: "rough idle", "vacuum leak", and it should point you in a direction.
Rich
Rich
#4
Nikki-Modder Rex-Rodder
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The carb idle problem is a vacuum leak- from what you describe, it's leaking on the left side of the carb as you face the carb from the drivers fender.
Regarding the timing, you don't check the timing by "front and rear" plugs. The top plugs are the trailing plugs, and the bottom are the leading plugs.
Get a Haynes manual.
If you still experience power problems at 5500 rpms, after you've set timing correctly and fixed your vacuum leak, then a new fuel filter is the cause.
Though you should replace it anyway (it's only a couple bucks and Napa always has 'em) noone can say if your power problem is due to your other problems or a dirty fuel filter. It just so happens that the "power cut-off RPMs" of a dirty filter is just what you described.
Regarding the timing, you don't check the timing by "front and rear" plugs. The top plugs are the trailing plugs, and the bottom are the leading plugs.
Get a Haynes manual.
If you still experience power problems at 5500 rpms, after you've set timing correctly and fixed your vacuum leak, then a new fuel filter is the cause.
Though you should replace it anyway (it's only a couple bucks and Napa always has 'em) noone can say if your power problem is due to your other problems or a dirty fuel filter. It just so happens that the "power cut-off RPMs" of a dirty filter is just what you described.
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