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New Weber, New Distributor, New Problem!

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M

MGBloke

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I have a 1967 MGB Roadster. I recently had a Weber dgv carb put in, as well as a brand new Mallory unilite distributor, just to improve performance. I've got the setting correct, I'm sure of it, and my timing light leads me to believe that the timing is right on too. But, the engine missed a lot. Hit, hit, miss, hit, hit, hit, miss, hit, miss, hit, etc., with seemingly no pattern. It has new plugs and plug wires, so I don't think it's them either. It idles decent, and doesn't die, and honestly, it doesn't quite die when driven, it just lurches around a whole lot. Any ideas. Thanks.

Joey
 
At whut RPM is the hit/miss coming on? DGV's are as (delivery) pressure sensitive as SU's... and float levels count too. I'm ~assuming~ here that the dizzy cap an' rotor are new.

This sounds like a "slop tolerance" in th' dizzy at th' drive dog.

Not quite enuff info to form a well thought out suggestion though.
 
I put a new weber on my 79 and it runs like a champ. Like the last fellow said, check the ingition system. Who knows, you might get lucky. My passion now is restoring my old 72. What a job!
 
How do you test a coil? It's pretty old and I wouldn't be surprised if that had something to do with it.

It's idling at about 1200 and the missing starts at about 16-20.

Dizzy cap and rotor are new.

I'm going to fuel around with the fuel mixture a bit and see what that does. I think I'll check the fuel line too to see if the flow is alright. Thanks guys. Any more advice is always appreciated.

joey
 
Best coil test for this situation:

Step one: Remove old coil, toss in nearest dustbin.

Step two: Fit new coil.

Neither hard nor expensive, and rules out that possibility.

Careful you don't lean it out too much.

I STILL think you should be looking to float level and delivery pressure... but that's just my tuppence worth.
 
In my last post I refered to my 79 that I installed a Weber carb. in. What I forgot to say is, that The Weber carb. is pretty sensitive to fuel pressure. Check your fuel pressure and make sure it doesn't exceed 3.5 pounds of pressure. That is the maximum pressure Weber calls for. If your pressure is at 3.5 pounds at idle, check it with the engine running at a higher RPM. If the pressure increases, check the alternator output. If the alt. is over charging, due to a bad regulator, some fuel pumps will put out a little more pressure due to the increase in voltage. Sounds crazy, but true.
 
Alright everyone. I feel accomplished, for I have solved the problem. It was as simple as possibly could be. The condenser on the distributor was going out. I just threw another condenser at the distributor and vroom, fired up, idled lean 'n' low, revs high 'n' mighty, and has more power than I've seen it have in a long time. Murphy's law, I guess. Try all the complicated solutions and when they don't work, spend about 5 bucks on the cheapest part possible, and only then will it work. Thanks a lot for your advice guys.

Joey
 
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