How come every Bronco seems to die every time you start it?

[Blue71]

Do any of you have this problem that are running Carbs? Every Bronco I have ever had with a V8 ......You have to pump the pedal several times. Start it...then it will die, Pump the pedal again it starts better the second time, but will either die again (usually), or run a little rough. (Even with the choke) Usually the 3rd time..it will start and run pretty good till it warms up. I mean every single Bronco I have had with a 289 or 302 will do this same exact thing. Are they bred this way? Surely from the factory they weren't like this. Then runs fine till you let it sit till the next day. Even does it in the Summer months too. Even my low miles '77 original Ranger will do it and it has the Duraspark ignition. Even all of my fellow Bronco onwers near me have the same problem. What is the cure?



Thanks Much,

Blue71

 

[scotts77]

Sounds to me like youre choke is set too lean. Roll it forward a click and see if it makes a difference.

 

[Skuzzlebutt]

Or all your fuel pumps are bad, allowing the lines to drain into the tank over night.

 

[Madgyver]

It's the fuel draining back....

 

[edgeoffroad04]

would an electric fuel pump help to fix it? when i first bought mine, one was installed, but since ive rebuilt it, i havent run one, sometimes I get this problem too on my 73.

 

[Naildriver111]

Mine did until a couple weeks ago when I installed this new carb http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=6607150587&ssPageName=STRK:MEWN:IT I put an electric fuel pump on last summer and it still died 3 or 4 times before I could keep it running. But I did find out the proper way to start one with an electric choke, and it works every time... turn the switch to on and press the petal to the floor slowly 1 time and release, then start.

 

[El Jefe]

turn the switch to on and press the petal to the floor slowly 1 time and release, then start.

This post hits home for me: I finally converted to Duraspark last night and i can definitely notice the improvement over points: It cranks less and starts easier. HOWEVER it still does EXACTLY what's described at the beginning of this post. My remedy is to do just what Naildriver posted above: 1 to-the-floor pedal pump; hold i there for 3-4 sec. and slowly release to free position THEN crank the ignition. Works 99.975% of the time.

 

[1977]

I have the opposite problem. First of all, two pumps when starting it for the first time every day, after that if you pump it again you'll flood it every time.

 

[j.r.nice]

My '77 did the same thing. It stopped when I installed the MSD billet distributor and the MSD ignition. Had nothing to do with the fuel delivery as far as I could tell. For the first time it started first crank aand I could walk away with it idling.

 

[SaddleUp]

This is probably a bad carb. Rather than the fuel draining back (Which shouldn't effect it anyway when it is first started) it is leaking out of the carb and down into the intake where it evaporates (While it is washing down and damaging the cyllinders). Then when you go out to start it pumping it the first time doesn't do much. It then takes one or two more times to refill the bowl after which it will start and stay running.

 

[El Jefe]

This is probably a bad carb. Rather than the fuel draining back (Which shouldn't effect it anyway when it is first started) it is leaking out of the carb and down into the intake where it evaporates

I have puddles of fuel every now an then at the intake. I have the 2BB Motorcraft carb - sounds like a rebuild is in order? (or can i make do with just new gaskets? - or new gaskets = rebuild kit??)

 

[SaddleUp]

I have puddles of fuel every now an then at the intake. I have the 2BB Motorcraft carb - sounds like a rebuild is in order? (or can i make do with just new gaskets? - or new gaskets = rebuild kit??)

I should have said that it can leak out on the outside as well depending upon the carb design and where the leak is. (If the float bowl hangs over the outside then it can leak onto the intake rather than into it)

As far as the gaskets your going to need to get a rebuild kit just to get them so you might as well do the whole thing (which I would do anyway). I would get this taken care of right away since this can create a hazardous situation for obvious reasons. If it leaks out while it is sitting then chances are it is also leaking out while it is driven.

 

[yellow66]

If you have a bad power valve, which is located under the front of the carb under a square plate, it will cause all of the problems that you are describing. It is not fuel draining out of the fuel pumps because you still should have fuel in the float bowl. If the power valve is bad you won't have fuel so the vehicle will stall until the fuel pump re-fills the bowl. You can buy a replacement for $5 - $10 and it should solve the problem as long as you adjust the choke correctly. Once you adjust the choke , when it is cold pump, it to the floor twice and then release it and it should start fine and keep running.

 

[musetech]

Though I also suspect my power valve is bad. Holley with electric choke. I've found that to reset the choke for starting I must slightly depress the pedal (I can hear and have visually seen the choke plate snap shut), to get it to start up right away and go to fast idle.

Also, depending on your ignition type, verify full voltage to the coil+ both in the switched on position and during cranking. Huge difference in starting.

Pumping it adds a ton of fuel. Not a good thing.

Much luck.

 

[Grunt1058]

My Bronco = 1/2 pump and crank. Starts right up every time and doesn't die on me at all.

But, it's not like my Bronco is stock by any means. Recently rebuilt 351W w/ Edelbrock 600 CFM Electric Choke carb, Full MSD Offroad Ignition, Electric fuel pump, fuel pressure regulator and gauge, stainless fuel lines from both tanks up to the electric valve and into the pump. Then single line from pump to carb.

So, basically, Everythings already been touched. ;D ;D ;D

 

[BG's 68 Bronco]

I have the opposite problem. First of all, two pumps when starting it for the first time every day, after that if you pump it again you'll flood it every time.

same here. Even if it sits for 3 weeks, 2 pumps... anymore and it gets pissed off at me ;D

 

[SaddleUp]

If the choke is set up right and everything is in tune then it should only take one pump to give it a shot of fuel and to drop the choke plate. The User Manual probably says one pump as well. (I know that is what it said in the Mustang manuals from when I had my 67/68)

 

[Grunt1058]

My problem isn't my Bronco dying (read my earlier post)

My problem is, once it starts, it jumps up in RPM until I romp it a bit to bring it back to normal. I know this is normal activity until the vehicle is warmed up. But, it's really annoying sitting at a stop light with my RPMs way too high and I was still on power drum brakes. I couldn't stand on my brake pedal to keep the thing from rolling.

Luckily... as of this weekend, I installed my power disk brakes. So, I don't have to stand on my brake pedal just to slow down. But, the excessive revving is still annoying.

 

[Naildriver111]

My problem isn't my Bronco dying (read my earlier post)

My problem is, once it starts, it jumps up in RPM until I romp it a bit to bring it back to normal. I know this is normal activity until the vehicle is warmed up. But, it's really annoying sitting at a stop light with my RPMs way too high and I was still on power drum brakes. I couldn't stand on my brake pedal to keep the thing from rolling.

Luckily... as of this weekend, I installed my power disk brakes. So, I don't have to stand on my brake pedal just to slow down. But, the excessive revving is still annoying.

Back off the cold idle cam screw (under the choke)

 

[SaddleUp]

Back off the cold idle cam screw (under the choke)

What he said. It sounds like the cold idle is set to high. The choke may also need to be adjusted a little so it shuts off faster.