Stalling

Reply Subscribe

Thread Tools

Search this Thread

Oct 29, 2012 | 12:22 PM

Zues1

Thread Starter

Cross-Country

Joined: Mar 2010

Posts: 72

Likes: 0

Stalling

73 F100, C4 tranny 302 with Edlebrock carb. The 302 has a mild cam, I do not know the specs of the cam nor does the seller. The tranny was rebuilt I was told and pulls, shifts hard.<O

</O

The engine dies at idle when coming to a stop and has also died at around 55-60 when letting off the gas. Put it in park or natural and it will fire right back up, shift to drive and it dies. This seems more pronounced the hotter the engine gets. <O

</O

I’ve increased the idle speed but that really seems not to help. I have replace and or tweaked everything I can think of, new dist with all new wires etc. , electronic ignition complete new fuel system, carb rebuilt, all vacuum lines checked and replaced where necessary. <O

</O

I’ve been told the truck needs a stall speed converter. What is everyone’s take on this? If this is the problem how do I know what converter is needed. Obviously I want to get it right this time and not pull the tranny again. <O

></O

>
With the research I’ve done it seems whoever was building the truck was on the right track with the carb, manifold, headers etc. installed and like myself was just was not familiar with a stall speed converter. <O

</O

Oct 29, 2012 | 01:18 PM

Wbruiser2

Senior User

Joined: Mar 2004

Posts: 280

Likes: 2

From: Alabama

I'm pretty sure that a stall speed converter has nothing to do with your problem. The reason you would need a stall speed converter is because you have a big ole cam and suped up engine and when you put it in drive it wants to take off on you. For example: I have a 2000rpm stall in mine so when I hold the brake and give it gas it will reach 2000rpm +/-a 100 before the tires start spinning. I think you have a vaccumn problem. I would check the seals on the front and back of your power booster (if you have one) and verify the lines are going to the right ports on your carb. There should be specific ports for the PCV, booster, etc... You could plug them all/one at a time just to rule out or verify a vaccumn problem...

Oct 29, 2012 | 02:38 PM

Zues1

Thread Starter

Cross-Country

Joined: Mar 2010

Posts: 72

Likes: 0

Yes it does have a booster.
I'll check that to see if I can locate a leak there. How would this be affected more as the engine temp increases? Also I've noticed the truck will pull itself unless you hold the brake, is that normal with a vac leak? Ports on carb are correct
I currently have vac gauge inline and it's setting on 18/19 psi at idle

Oct 29, 2012 | 07:59 PM

RWENUTS

Senior User

Joined: Jul 2011

Posts: 151

Likes: 1

From: Nanaimo BC

You need more timing!
What's your timing set at?
Is your vacuum on the distributor hooked to ported or manifold vacuum?

Oct 29, 2012 | 08:14 PM

Wbruiser2

Senior User

Joined: Mar 2004

Posts: 280

Likes: 2

From: Alabama

Quote:

Originally Posted by Zues1

Yes it does have a booster.
I'll check that to see if I can locate a leak there. How would this be affected more as the engine temp increases? Also I've noticed the truck will pull itself unless you hold the brake, is that normal with a vac leak? Ports on the carb are correct
I currently have vac gauge inline and it's setting on 18/19 psi at idle

If it is in fact vacuumn related, heat can cause rubber to soften and expand which would cause a small hardly noticable leak to become bigger... 18/19 PSI at idle with a cam? That's good in my opinion, I can only get about 15 at 12btdc which is where it runs the best.

Oct 30, 2012 | 08:22 AM

Zues1

Thread Starter

Cross-Country

Joined: Mar 2010

Posts: 72

Likes: 0

Quote:

Originally Posted by RWENUTS

You need more timing!
What's your timing set at?
Is your vacuum on the distributor hooked to ported or manifold vacuum?

I don't recall where the timing is currently set as we've tried advancing and retarding the timing and continued to have the same results.
The vaccum for dist is hooked up per the edlebrok DVD instructions I ordered. We've tried swapping these ports, same results.
I'll be suprised if it's a vaccum issue as we've chased that senerio for sometime as that seems to be the most obvious cause. Every hose on this truck has been checked, rechecked and replaced.
It was suggested a possible leak around the booster and when the weather clears I'll give that a new look. However I replaced the booster when I purchased the truck 2 years ago. Not much chance the rubbers are rotted at this point.
We're stummped!

Oct 30, 2012 | 08:40 AM

Wbruiser2

Senior User

Joined: Mar 2004

Posts: 280

Likes: 2

From: Alabama

Yeah you can probably rule out the booster then. Any easy test: start the truck and let it fun for a minute and turn it off. Wait ten minutes and press the brake pedal. If it's hard it's not holding a vacuumn. You should be able to press it twice fairly easy though. The only thing else I can think to check is the modulator and the line running to it on your transmission. If that's not it, I'd start all over from the beginning... Timing, fuel, etc... Maybe you missed something.