A few changes and I’m stumped

[Hipopinto]

Hey all

I changed up my mechanical fan in my galaxie to a Lincoln mark viii

I also changed the alternator to a 3G 150 amp to support the fan

Up until this time I NEVER had the electric choke connected on my summit vacuum secondary 750

I would just snap the throttle until it’s up to temp and go

My car previously ran awesome!

Now the fan works as it should and running the bigger alternator needed an idle adjustment obviously due to the added load

While driving the car “feels” like it’s REALLY working

It never did before, it just WENT!

I was driving at 55 mph pushed the gas in 4th and the car surged and backfired

What would cause this?

I’m stumped as I have never had these types of issues with the mechanical fan and the 1G alternator

I’m going to let it cool down stone cold and unplug the electric choke wire to see if that helps anything

What do you all have to say?

I’m stumped and don’t want to change too many things and make it worse

Thanks guys
Dave

[HarleyJack17]

Did it backfire through the exhaust or the carb?
What ignition system are you running?

[C8OZ]

Any chance the distributor hold-down isn't super tight and you bumped the timing down a bit while installing the fan?

[Hipopinto]

It sounded as if through the carb

I am running a duraspark with HEI conversion and it has always performed well since these changes

I will check the distributor timing again with timing light
Dave

[Hipopinto]

Ignition performed well since before I made the changes

Would the added load of the alternator change everything this much?

Or is that choke messing with it?

Dave

[Gaugster]

From the first post I am reading that the idle speed had to be increased due to the "added load". That sounds strange to me as you removed a mechanical fan. Generally the result of less load and more HP when the mechanical fan is removed even if a better alternator is added. I'd return the choke to how you had it before and see if that fixes the problem. It just may not be opening fully and making the engine run fat and sluggish.

Otherwise my guess is that something got bumped and disconnected during the upgrades. Increasing the idle speed will open the butterflies and in extreme cases start using fuel from the main jets. This can make all sorts of run issues. Check the timing and make sure all the plug wires are in good shape and have a solid connections. Look for a vacuum leak or something else that could impact engine idle. Is the new alternator working well? Should be 14V+ or so when running.

[Hipopinto]

Ok!!!

As soon as I get home I will start checking!

Dave

[shady]

First thing I would check would be the output of the alt. make sure it is giving you 14 volts.

[Falcon67]

>Now the fan works as it should and running the bigger alternator needed an idle adjustment obviously due to the added load

Ummm - no.  Even at max output, where it should not be anywhere close, it would theoretically consume max around 2 HP.  I run a 3G on the door car, likely a 100~120A unit and it puts virtually no load on the engine.  Even when spinning at 12000+ RPM on a pass.  Running dual large fans drops the system voltage from 14.5ish to the low 13s but the idle RPM doesn't change. 

[Hipopinto]

Guys I’m an idiot

I cracked the top of the PCV valve some how causing an awful vacuum leak

Timing was spot on and I started looking for vacuum leaks

I could barely see the crack but what a change it made

I will install a new valve tomorrow and follow up

Thanks for all your help guys

Dave

[cammerfe]

You started this whole thread to make the rest of us feel better. We've ALL done something like you're describing. In my own case, doing a tune-up for a friend, I searched for a half hour, taking the diz cap off several times, while looking for the reason the car wouldn't start. I finally stepped back to look things over from a bit of distance, and discovered the rotor setting to one side. It's really hard to get a car to run with no rotor in the diz!!!

KS

[FERoadster]

OK not a FE but in my 1948 Lincoln with a 1957 Caddy engine. Woodward Cruise about 25 years ago southbound and just passed 13 Mile Rd.  about 9:30 at night . Car just quit so a number of onlookers pushed it behind the curb. Tried everything ( had fuel  and compression but no spark) . So about 1AM had the car hauled about 35 miles to Lake Orion Michigan  my house.
Next AM with a clear head checked everything fuel, dist. turned but no voltage to the coil. Ended up being a broken wire from the points to the condenser inside the Distributor . I couldn't have ever figured that out with 15 people looking over my shoulder at 11:00 PM. Lesson learned never deal with a 1957 Caddy engine. 

Lincoln now has a 390 FE
Richard >>> FERoadster

[Gaugster]

Glad you found the problem. I hope it's just that one item that needs fixing. I've never had a close look at my PCV check valve but will now just in case.

[Falcon67]

Its the little stuff sometimes!  Good catch, back in business.

[Hipopinto]

I had to eat a big slice of humble pie!

Dave

[turbohunter]

We all eat it at one point or the other Dave.

[Hipopinto]

Thanks for being so great guys!

Other places on the internet aren’t so cool to deal with

Dave

[C6AE]

In 1965 I had a '55 chevy with a '56 Cadillac engine. Did not build it, it was sort of high school butcher job.
But that old Cadillac had enough torque to snap the chevy axles every single weekend...
They deserved each other, I gave it up for a '39 Tudor after a few months!

[Gaugster]

Thanks for being so great guys!

Other places on the internet aren’t so cool to deal with

Dave

I know what you mean. For what it's worth I had a good look at my own PCV setup. There was a slight vacuum leak in the hard plastic elbow that mated with the valve itself. At least with the hose sitting on my work bench. So I swapped in a new rubber elbow and it's all good now. Didn't really change how it runs but who knows how old the original plastic piece was.