HEI help

[BigIrish]

Took the '30 out this afternoon and all of a sudden started running terribly. Misfiring randomly on all cylinders.

Engine is a stock Ford 351 with a brand new Summit Racing HEI and brand new Edlebrock 600 Performer. Less than 20 miles on each.

It happened all of a sudden so makes me thing electrical. I verified fuel filter is not clogged. I ran a new power wire to the distributor, no difference. I ran out and got a new ignition coil, no difference.

What else could go wrong with these distributors. Electronic guts went bad? Engine will rev, but misfiring the whole time.

 

[sneakysnake]

Modules are cheap enough,I would try that next.You might check the ground in the unit, they say thats what knocks the modules alot of times.

 

[RPM]

My experience with an HEI is it either works or it don't work. I think I would be looking for maybe a float sticking in the carb. What does the exhaust look like any black smoke?

 

[BigIrish]

There's no black smoke, no smoke at all that I see. I checked the plugs and they were a nice light brown color.

I also cracked open the top of the carb and looked inside to make sure there was no trash - crystal clean.

I checked the grounds and they weren't super tight. Think that messed something up? I guess I'll try the $20 module to rule that out then look at the carb.

I really hope its the module...

 

[Old Iron]

Don't rule out a lobe off the cam.
Been a lot of that going on lately, especially if you don't run zinc additive or a roller cam.

 

[BigIrish]

Well thanks for the replies everyone, but I figured it out thankfully. The cause is my own fault.

I'm still running the stock 2bbl manifold which has an EGR port that needed to be blocked off (and yes I'm also running a crappy 2bbl to 4bbl adapter for now).

In my haste to get it running, I just blocked the port with a normal paper gasket. I was going to go back and make a metal plate but forgot. Anyway as soon as I had enough revs the vacuum sucked a hole in that gasket. The exhaust gas from the EGR port was pouring into the intake. I'm really surprised it ran at all.

So all is well now. Merry Xmas!

 

[Dirtyrat]

Hey, at least its a cost free issue!
Glad you found the issue!

 

[Old Iron]

This is a KISS moment

Dooooo