Stalling 1971 Bronco problem

[smith15]

I just realized that I posted this in the wrong section originally....

Hello Everyone,

New to the forum and I already have a problem....

I have a 1971 Bronco that Idles great, sounds great when I rev the motor but when I try to drive it she stalls. I've replaced the plugs, plug wires, upgrade to HEI distributor, replace the carburetor, alternator, battery, fuel filter, fuel pump, fuel line, timing chain. Anyone have a similar issue or think they might know what could be up with her?

I have what looks to be a stock motor in her although I was surprised by the width of the plugs. It has those real thick spark plugs on it so I was wondering if the heads might actually be off of 60's 302 or something. It has a new 2bbl carburetor and all the new stuff that I mentioned above.

Thanks in advance for any help you guys might be able to provide!

 

[Bully Bob]

Hi Mr. Smith.., welcome..!!

Those sound like the correct stock Ford type plugs.

"...when I try to drive it she stalls"

Do you mean flat out quits running.., or stumbles but keeps runn'n...?

Do you mean stalls instantly, or randomly somewhere down the road.?

"I've replaced the plugs, plug wires, upgrade to HEI distributor, replace the carburetor, alternator, battery, fuel filter, fuel pump, fuel line, timing chain"

What did it run like B4 all these piecee parts..?

Best guess at this point would be carb. settings, vacuum advance, &/or a faulty accelerator pump.

Then, ignition/timing. Also NOTE; plug gap should be wider with the HEI ign.

(I removed your other 'duplicate' post so as to prevent confusion)

 

[smith15]

Thanks Bully Bob,

She backfires out of the carburetor and then she flat out quits running. She will drive idling up the road but as soon as I give her any gas she stalls right out. I had been having stalling and starting issues with truck so we replaced the points in the distributor and timed it at top dead center. My friend who was helping me with the work told me that the timing had been a full tooth off. Once we timed it correctly we were getting extreme vibration at idle and stalling out when you try to drive it. We then replaced the points distributor with the HEI distributor, new plugs, wires, etc. Still had the same problem and we figured there was some slack in the timing chain. We replaced the timing chain and found that the original timing chain was badly stretched. When we buttoned her back up the vibration at idle was gone and it idles and revs great now. However, it was still stalling right out when you apply the gas. So we figured the carburetor was having an issue so we replaced the carburetor but it still ran the same. That's where I'm stuck at now.

 

[Bully Bob]

Not much else to check except a couple things/questions;

"...so we replaced the points in the distributor and timed it at top dead center."

Is this a correct statment..? I believe it should be 6-7deg. advanced.

With the vacuum advance off.

I don't think "0" works with todays fuels.

"My friend who was helping me with the work told me that the timing had been a full tooth off."

This statment actually refers to the timing chain & gears. The dizzy can be a tooth off so to speak.., but rotating the dizzy makes up for it.

The proceedure

(assuming the timing gear dots lined up upon installation)

Insure that the piston (#1 cylinder) is at the top of its COMPRESSION stroke

Set the harm. balancer timing mark to "0" deg i.e. "top-dead-center"

(it should actually be there)

Pull off the dizzy cap..., rotor should be pointing to the #1 cyl. prong on the dizzy cap.

----if not.., rotate dizzy 'til it does. ----

With everything in place.., start the eng.., & with a timing light, rotate dizzy to 6-7deg adv. Tighten down ths dizzy lock bolt.

If it doesn't run right now..., it has to be a carb issue.

We'll talk then.....

B