Stalling In Drive

[85bronk460]

i just bought a 85 blazer with a 460 in it. it will run in park and nuetral but will stall in reverse and drive. i noticed it only had a 2bbl carb on it. ould that be the problem or is the idle set to low?. thanks for the help in advance

 

[Windchaser]

I truly hope that you mean BRONCO, and not BLAZER- A) because chevies ****, and B) because why put a 460 into a chevy where a 454 would fit nice.

Just messing with you, but Welcome to the Zone.

If you do mean a 460 bronco, (and even if you mean Blazer) then unplug your MAP SENSOR. It is located at the top of your firewall on the passenger side. Just a plug that you unclip. When I put my 460 in mine, my mapsensor went nuts, killing my truck and making it stall. Even with the 460's computer installed. Try that and let it run without it for a while...it will burn through the gas even more (I got 5 mpg when I did it) but it will run...Then after a couple of days hook it back up (while running) and check your timing. Thats what I did and mine is fine now.

 

[stinger]

85 with a carb any computer controls? well i dont have puter controls on my 85 with a carb maybe that the in gear idle is to low.

 

[sweepersrgr8]

The 2bbl is your problem. I've never seen a 460 with a 2bbl, didn't even know Ford produced them.

Unless it's a feedback type carb, you won't have a MAP sensor. Your idle should be around 650 RPMs in drive, but you have to take the engine, and any modifications into consideration. After the timing, and carb is set up properly, I would set the idle 50 RPMs below where the truck starts to creep forward on its own.

If I were you I would go back to the 4bbl. The Motorcraft (Holley) 725 CFM was the most common one that Ford use on the 429/460. If you look at the 2bbl you will notice the primaries are almost as large as a 600 CFM's secondaries, but it has smaller jets, so you are probably just leaning out too much when you put the truck in gear. The primaries on a 4bbl are smaller, and the jets are changeable to fit your application. As long as you keep your foot off the floor, you will get better gas milage from the 4bbl, but the extra power will be there when you need it. An out of the box 750 CFM Holly should put you at a good starting point.

 

[tveronee]

This may sound stupid but does it have the E4OD transmission? If it does and the first and reverse gears got hot enough to weld themselves together it will do exactly that. I had the same problem and ended up converting to a C6.

 

[Seabronc]

Assuming that this is actually a Bronco, my first question is, are you sure this is a 460 ? Bronco did not come stock with a 460, so if it is, it must have been installed later and I can't immagine someone swaping in a 460 and leaving and putting a 2 bbl on it. The 351 did come with either 2bbl or 4bbl and I wouldn't have either engine with a 2bbl, just my preference /emoticons/[email protected] 2x" width="20" height="20" /> .

That being said, with a non computer controlled engine, Duraspark II, a couple of things that will cause that type of stalling are vacuum related and choke. If you let it come up to normal operating temp, will you be able to run in drive and reverse ?

Definately do a tune up. Then set the idle speeds. When at normal operating temp, disconnect and plug the distributor vacuum hose, put throtle on the highest cold idle step (rpm for this step should be approximately 2100 RPM), if not adjust the cold idle ***** to get that. Reconnect the distributor vacuum and set your curb idle ***** to approximately 1600. Fot on brake, put in drive, idle speed should be approx 650. If it starts to stall, put back in park and bump the curbe idle up a little. Repeat untill it idles in gear. Like Sweepersrgr8 said then add approx 50 rpm.

The choke either not opening or opening too soon will also give this type of problem. Assuming it is an automatic choke, check the position cold and then watch to see that it opens. It should be fully open with the engine warmed up. If it to comes off too soon it will give a similar problem. A lot of people go to manual choke to resolve this, but it can be adjusted properly with a bit of patience.

How about posting a picture of the engine. like they say, "A picture is worth a 1000 words".

Good luck,

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[hawk2100n]

hey seabronc, you have the same carb on you 351 as me. do you have manual choke. i set the choke for startup and bump up the idle with my foot, i have to let it warm up for a minute and then i can go. usually only fall, spring and winter. do i need to adujust my carb? do you have a similar startup procedure. also, this is only in the morning or the first drive of the day. if i dont drive it early, like on the weekends, it wil start a little easier but not mutch. any adjustment necessary. thanks

 

[Seabronc]

I'll PM you with what I went thru with mine. But the basic answer is most likely.

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