Need help from people who know carb'd v8's

Awesome, thanks for the pics, that always helps. I've got a small to do list from you guys and alot more researching to do, hopefully I'll get it back up and running. Thanks for the feedback so far, and appreciate any further input as well!

 

Do you know what year 350? (it also would help to ID the ignition/Dist.

I think with GM's the HEI ( i think its called hei ) came out in late 70's , maybe early 80's & the coil was in the dist. cap which was GM's first electronic ign. , its pretty reliable, did you cross any plug wires ?

I'm thinking tho' that Edelbrock carb will be suspect, they are very touchy & are known to "glitch" pretty regularly... but ya just gotta go over your work again dbl/triple check.. any backfiring /missing when it does run ?

or does it run smooth more or less & die when you give gas ? (vaccum ?)

 

I'd do one thing at a time so clean your points, plugs and re-gap, reason for this is your learning and to eliminate one thing at a time you'll then know what affects what. To check your jets simply get to a vantage point where you can see inside the carb, with your hand you can turn the throttle and you will see the mist spray. This likely isn't the reason it won't start but could be the reason for hard starting and shitty power.

Once its running on its own you can check for a vaccum leak by covering the carb with a towel or shirt(carb will have to be open no breather on top then throw shirt/towel on top), if it dies no leaks, if it still runs you have a vaccum leak to address.

 

I don't know how to tell the year, the original stamp has been removed, and there is a reman stamp from being rebuild and sold as a crate motor, but I researched the number and couldn't get a year from that. The oil dipstick is on the drivers side though, I know that changed sides at some point...

I definitely didn't screw up wires, I did them one at a time and pressed them on hard. It doesn't do much of anything when it does run, its only seconds, and only while the starter is still helping it out.

Before when it was running, it would bog down sometimes if I gassed it very hard.

Heres a pic of the motor, not a good one, but I can try and get a better one tomorrow of the back so you can tell what ignition it has.

 

Thats a great tip on checking for leaks.

 

It's been awhile since I've dealt with anything that old, but many vehicles with points ignition had a "ballast resistor" wired inline with the ignition coil. It dropped the voltage down to around nine volts to make the points last longer. When the engine is cranking the starter solenoid bypasses the ballast resistor and gives the coil a full twelve volts. If the ballast resistor is out, that could be why it only runs while cranking.

If you pull the air cleaner and get a good picture of the distributor, that would help tremendously. With the air cleaner off, you can also see if the choke is working correctly, and you can look down the carb and see if the accelerator pump is working properly inside the carb. When you push the throttle down, there should be a visible shot of gas in the carb as you are looking down into it. Don't put your face there while trying to start! Just with the engine completely turned off.

GM HEI ignition doesn't use points. If that's the system you have, it's common to have the ignition modules fail. They frequently will work till they get hot and then shut down, at least in the early stages of failure. Bogging down when giving it gas could also be an early symptom of a coil or module starting to die.

 

Good input, thank you! I will definitely be posting up a pic of the distributor tomorrow so hopefully you guys can tell what type of ignition it has.

This may also be a problem, but there is no choke hooked up, or not that I can tell. On the ps of the carb, there is a wire hooked up to a knob in the cab that is just loose, has no function. I did order an electric choke a few days ago, hasn't got here yet.

 

I used to always buy manual choke carbs and use a wire to secure them Open/closed basically not working. I would warm the vehicles up using the pedal. Now my winters aren't cold here so no big deal for me.

For you the loose wire is to be pulled, when done it will choke the engine then once warm you push it back in and then drive on.

 

Check your timing get a timing light and set it to 12degrees. Or just loosen off the dist and turn it slightly while someone's turning it over.

 

Thats def. an older 350, I'll bet its got a little slide up metal door on the dist. to set points/dwell & it can all be done while running, I was thinking the HEI also till i saw pic & yep was looking for a ballast resistor too.

I wonder if the dist. has been taken out (180' out) from the way described sounds like it seems to want to fire with starter. (no spark) shoot some starting fluid (if ya have good bluish spark) & see if it will actually run

 

Here's a picture of each side of the carb and the ignition setup on the back. Maybe some of you smarter than me will be able to come up with a year for the motor from what you see. Was too cold to do anything to the truck today, hoping for better weather tomorrow.

 

Well you def. have the HEI electronic ign.

 

So any guess on what year of truck this motor is from? If I have the HEI ignition, does that mean I have a ballast resistor that is the possible problem?

 

no ballast resistor

 

Ok, so I figure this is a good time to upgrade some parts and eliminate some problems. I found a good deal on an MSD cap and rotor.

Anyone know what year this motor could be though? I'm trying to get a new set of plug wires and I think I need to know the year range for this motor.

 

Shouldn't make much of a difference, just get wires for a chevy V8, then match them up, as you pull one find one that length from the box.

 

Huge diff. the HEI wires are alot thicker

 

What I mean is when you tell them you have an MSD Cap and you need wires let them know its for a cevy V8 and the box will have the correct lenght wires.
I was assuming she was going aftermarket with all the new parts not stock.
Thanks for catching that.

 

Let's back up over here and work on the basics...The truck I was driving this weekend is a 68 Dodge D100, headers, holley, stage 1 intake, glass packs, so I am VERY familair with old iron.

Since she is in SD where it is COLD, is the choke working? It sounds like one side bank of the engine gas fouled.

1) step 1 make sure choke is working, while the electric chokes are nice, they only really work well on stock tuned engines. Bogging/missing when cold is probably a lean condition.

2) are we getting SPARK at the plugs...get a $5 spark checker at your local FLAP, put it between a where the spark plug goes and ground. Have someone crank the engine, look for a big, fat blue spark. You can gap the spark checker to MATCH your plug gap.

3) I suspect since this truck probably has modified exhaust/intake it is going be LEAN off idle, and some additional tuning to the accelerator pump/curb idle air fuel mix is going to be needed.

If you want, email me a hetkind@bestweb.net and can help you get this running off line.

 

OP, probably the best way to ID this engine is running the numbers on the side of the block thru a good manual (MOTORS manual used to have a chart but dont know if their around anymore)or parts house, they should know..

OH WAIT !! better still run those numbers thru a wrecking yard they can DEF. tell you...