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Fri Jun 27, 2014 3:24 pm

I have a dead cylinder and need a way to locate it besides pulling the plug wires. I'm running IDAs and we all know it's a giant bitch to get access to the plugs on cylinder 1 and 3. I just changed the plugs so that is out of the equation. I'm running a Mallory Unilite with a Hyfire 6AL box. I'm also curious to know if there is a way to check the plug wires with a multimeter. The plug wires are Aroura spiral core 8mm wires. Thanks for any info.

Fri Jun 27, 2014 3:39 pm

Try pulling plug wires at the distributor cap.

Fri Jun 27, 2014 4:19 pm

Some of the old tricks:
the old, see which exhaust pipe is hotter than the others, now with IR thermometer.
Using a neon bulb pen tool (champion ct-436) to see which spark plug wire is acting different.
Instructions
http://books.google.com/books?id=lNQDAAAAMBAJ&...mp;f=false
http://www.aliexpress.com/item/Free-shipping-car-r...98776.html
Spark plug wires should have X-many ohms per foot. Some are as high as 5000 ohms per foot, so you have to know what it's supposed to be, or compare them. The good spiral wires are WAG maybe just 500 ohms per foot or something like that. Hopefully the manufacturer says what it should be.

And of course......observing the spark plugs

Fri Jun 27, 2014 6:08 pm

With the plug wires off at the cap there are sparks going all over the place!!!! The warm exhaust runner vs the cool one is on my to do list thanks Glen. I'm hoping this won't be expensive... I'm thinking I could also have a tight exhaust valve as there is popping/backfiring in the exhaust. thanks Doug

Fri Jun 27, 2014 6:21 pm

c.ruber wrote: With the plug wires off at the cap there are sparks going all over the place!!!!
That's a problem, maybe start with a new cap and rotor.

Sat Jun 28, 2014 6:02 am

Check your idle jets

Sat Jun 28, 2014 11:18 am

Maybe I misspoke about the problem I'm having with the engine. It has a miss at higher rpm with popping out the exhaust. I adjusted the valves and still has the same problem. Definitely not a smooth acceleration from idle, very rough with the popping in the exhaust. All four exhaust runners are hot(used my hand). I think the carbs may be out of sync.
I tried to sync them with my snail synchrometer. I found them to be off just a little. So I disconnected the linkage (CSP) and tried to adjust the idle speed screws on the IDAs. When I did the 3/4 side, the engine just quit...After trying to start the engine again several times I gave up. Vacuum leak?? I just replaced the manifold base gaskets, although I feel that the amount of gasket is thin after cutting them to match the intake port. I'm frustrated and running out of patience.

Sat Jun 28, 2014 11:55 am

:) There are different methods used in adjusting duals....matter of choice.

I always would disconnect #1/2 carb.

Back off the mixture screws 2 turns.

Turn the idle screw just enough so the throttle plate moves and then 1/4 turn more of the screw.

Would then start engine and allow to warm up.

Depending on the cam, idle will vary.

I like the Unisyn...chose the middle mark as a idle reference to equal the carbs idle position.

Once they are in synch will slowly turn in the mixture screw on each throat until engine hesitates and then back 1/4 of a turn.

The mixture screw will vary depending on the size of the Jugs inside.

Will double check with the unisyn for comparison etc if needed.

Then will blip the carbs using both hands for positive response.

This procedure above may take 2-3 times doing until things are satisfactory and then will re connect #1/2 linkage.....adjusting as needed for equal carb response.

I had 48IDA carbs on my VW dragster until going to NOS and then a Turbo.

They are easier to work on then the 40/44's

Sun Jun 29, 2014 5:27 pm

I'm gonna have to put this on the back burner until I get some parts in the mail. I'm gonna try a different set of manifold to head gaskets and see what I get after that. I hope it's as stupid as a vacuum leak. Do any of you use a sealant/adhesive to keep the manifold to head gasket from sucking in and creating a vacuum leak? The last time I installed a set on my engine there wasn't much gasket after I trimmed to match the intake port. Thanks DS

Mon Jun 30, 2014 9:12 am

I swapped my 55 idle jets for 60 idle jets and have the same problem. When I pulled the plugs they all looked good but #3 had a lot less carbon on it than the others. I know #3 usually runs hotter,so this normal?

Mon Jun 30, 2014 12:38 pm

I was having a similar problem as you chanced the distributor cap and problem solved. The point on the old one were worn out and with some corrosion.

Mon Jun 30, 2014 6:12 pm

I am beginning to think it's a synchronization problem. I am not convinced it's ignition related. I will replace the manifold/to head gaskets this week. I will then go about synchronizing the carbs as described on the ACN site. Crossing my fingers...

Mon Jun 30, 2014 6:47 pm

Googled hyfire 6al because anytime I hear 6al it is with msd and not misery. Appears there are a lot of people having problems with it.

Mon Jun 30, 2014 7:10 pm

bypass the CDI and see if the problem remains. The less complicated the better when troubleshooting.

Tue Jul 01, 2014 5:21 am

If all that great ignition advice is no help- check all your valve springs for tension- a light intake could bounce and set off all kinds of problems- please define "high revs" for us.

Tue Jul 01, 2014 5:47 pm

High revs in this case is when the popping begins at around 2500rpm.

Thu Jul 03, 2014 12:23 pm

Removed the carbs and manifolds and installed new intake gaskets. Reinstalled everything except the linkage and can't get the engine to idle any lower than 2000rpm. Touched the #2 ignition wire near the spark plug and got a nice shock. Now what to do? I'm stumped.....

Thu Jul 03, 2014 4:09 pm

New cap, rotor, and wires. Then check the spark wire connection at the coil. Mine was worn/not making a good connection. I had the exact same symptoms. i just bought a new coil and 'whabam!' she runs good again.

Thu Jul 03, 2014 4:11 pm

Ditto what splitdog said I did the same and runs like a champ

Thu Jul 03, 2014 4:12 pm

When it's misfiring and popping out of the exhaust is the smoke black? If it's black, the problem is ignition. Go for the easy suspect first and change the coil. Check your plug gaps aren't wider than 35 thou. Don't go crazy with racing CDI plug gaps as it usually causes more harm than good. Just because you've taken a good poke off an ignition wire and the sparks fly doesn't mean the coil isn't at fault. If that doesn't work, swap out your distributor cap. Also make sure the firing order is correct. Fred

c.ruber wrote: Removed the carbs and manifolds and installed new intake gaskets. Reinstalled everything except the linkage and can't get the engine to idle any lower than 2000rpm. Touched the #2 ignition wire near the spark plug and got a nice shock. Now what to do? I'm stumped.....