Engine help

[ffmedic86]

Hey everyone, I'm new here, but been a stalker for several years. I recently purchased and built my UCC 427. Love the car, but since the 7 day build was complete, been having some problems. The car keeps stuttering and then dying while I'm driving. Its like it is running out of gas, then dies. It will start right back up with no problems at all. I will then it runs fine and may or may not have the problem again. Sometimes it does it every 3-4 minutes, and others it may be 20 or 30 minutes before it does it again. I have been working with UCC to fix the problem, but here we are after 4 months and still have the same problem. I'm looking for a little help. I have replaced the pick up coil on the distributor twice, the distributor twice, and now the MSD blaster SS coil. None if it has fixed the problem. I have also cleaned out the fuel filter, fuel lines and tank just to be safe. I have also checked the carb and there is always fuel in the bowls.

The engine is a 347 stroker, MSD coil and MSD AL6 ignition box and MSD Pro Billet distributor.

Everything I have read is that the MSD 6AL box either works or does not work, there is really no such thing as partially working or "going out".

So any help would be much appreciated.

Thanks
Brad

[Dwight]

fuel filter to small?

clogged fuel filter?

to many fuel filter?

fuel line restriction, fitting to small or a dent in the fuel line?

coil going bad?

MSD box going bad?

Dwight

[CHANMADD]

I know you said that you cleaned the tank.........once this turned out to be a little paper in the tank which would get sucked up the end of the pickup tube......

[ffmedic86]

If it was a problem with the fuel line, or something in the fuel line, then wouldn't it happen immediately after I shut the car off and restart it?. The Fuel filter is actually about 8 inches from the fuel tank and appears to be the right size. Its the same fuel filter that they have been using for some time.

The other thing that makes me believe that it is not the fuel is that the Tachometer starts jumping around like crazy or goes straight to 0 when it starts stuttering and dies.

[Dwight]

The other thing that makes me believe that it is not the fuel is that the Tachometer starts jumping around like crazy or goes straight to 0 when it starts stuttering and dies.

by pass the box or have it checked by MSD.

Dwight

Roll Tide

[Phx Mike]

Given what you are seeing on the tach I am thinking it is an electrical problem. Since it starts back up after you have the problem and then has the problem again later, intermittently, I would check your ignition switch - it may have an intermittent contact when in the run position. You might try starting it and slightly touching/wiggling the ignition key a bit and see if that prompts it to act up. If in doubt, check the connections on the switch and replace it.

[Texasdoc]

I agree with the electrical. Check all the grounds too, including the battery to frame and the msd to ground. I have a spare msd (actually Mallory but same connections) box you can borrow to test with.

You can also disconnect the tach to make sure you aren't getting feedback into the msd.

I also run an MSD 8830 capacitor to ensure my box gets clean power.

[cdnus]

Where is your msd box mounted?
Does the shutdown occur at speed or when you are in traffic or driving very slow?
Is this happening when the ambient temperature is high, if so have you tried driving in cooler temps, eg. Cool evening temps.
If your box is mounted where it will get too warm it will send erratic tach signals and could cause temporary shut down.
A quick test is when it shuts down quickly and carefully put your hand on the box, if it is too hot to keep your hand on it, it is probably the cause of the shutdown.
I chased this gremlin for a year and eventually solved it by relocating the box.
Hope this helps
Craig

[bobcowan]

I had a similar problem with a brand new car I built last year. I finally tracked it down to a faulty circuit breaker to the fuel pump. A brand new part, bad out of the box. It happens.

With engine running, start shaking a jiggeling stuff until the problem occurs. I know that sound unscientific, but sometimes it works. Could be something as simple as a loose ground connection, bad relay, or loose fuse.

[scott cooper]

Check the vent in gas tank, I have had the very same problem

[Texasdoc]

If it dies and you still have full fuel bowls, it's not likely fuel pump, fuel electric circuit, filter, or fuel line related. Do you have clear sight windows or the plugs? When it dies immediately turn off the ignition then look to see if the bowls are full. If they are full, look elsewhere. If the bowls aren't full, it is a fuel supply issue. If they only are less than full, you could be running lean causing it to die.

Remember: you need air, fuel, and spark. Air is easy - not your problem if it runs at all. Fuel: if the bowls are full, that's not it. You are left with spark. Perform the above checks and let us know what you find.

I'm in Keller and would be happy to look at it sometime.

[Gaz64]

Have you checked/verified the fuel tank is vented enough?

[Texasdoc]

Originally Posted by Gaz64

Have you checked/verified the fuel tank is vented enough?

If the tank wasn't vented enough, he would get a vacuum in the tank and it would prevent the pump from working to its full potential. Less flow with increased fuel consumption would drain the fuel bowls, right? If the OP has full fuel bowls, it isn't a fuel delivery problem. Or maybe I'm missing something. (Wouldn't be the first time.)

[Phx Mike]

Brad (OP) if you have not already verified this, then next time it occurs, before you try to restart it, pull the air cleaner and open the throttle a bit. If you get a good squirt into the carb you know it is not a fuel issue but rather an electrical problem. Given that it runs well when it is running, and starts right back up after the problem does occur, it sounds like a primary side electrical issue and not plugs / plug wires. I think the most likely culprits are your ignition switch and/or connections, loose connection at the coil or MSD box, or grounding of the MSD box. As suggested above you might try wiggling these connections with it running. Start with the easy stuff first. Good luck!

[Gaz64]

Originally Posted by scott cooper

Check the vent in gas tank, I have had the very same problem

Originally Posted by Gaz64

Have you checked/verified the fuel tank is vented enough?

Sorry Scott, didn't see you have already asked this.

Gary

[G-Pete]

Originally Posted by bobcowan

It Could be something as simple as a loose ground connection, bad relay, or loose fuse.

My thought exactly...

[iva bigan]

Brad
I had a very similar problem with my car,it turned out to be a blade connector on the end of a fusible link,it had melted down causing an intermittent connection, all good after replacing the connection ,the fusible link is located on the positive power terminal (end of the battery cable)usually near the starter motor.

Iva Bigan

[talos]

Myself I think it is the MSD ignition box or low voltage. Please let us know your findings, I am interested. Thanks, Tom

[Gaz64]

What model 6AL do you have here, analogue or current model digital?

Does sound like a poor connection, either the pickup harness, or power/ground.

You only need one bad female.

[GBowman]

Originally Posted by Gaz64

What model 6AL do you have here, analogue or current model digital?

Does sound like a poor connection, either the pickup harness, or power/ground.

You only need one bad female.

Haha...yes, 1 is most definitely "enough"!!!