All of a sudden, out of nowhere today my truck starts acting like it's some 3cyl geo metro with a turbo. Basically, I have it floored and it starts going as if I'm barely touching the gas. from 0 to 29MPH it does this. Soon as it hits 30, it acts likes some sort of rice burner with a turbo spooling and all my power is back and it acclerates like it should. But if I take my foot off the gas, even above 30 it goes back to no power. I was playing with my carb and my choke won't close all the way, it only closes to a 45 degree angle about and then when the truck is running it'll stay fully open. I'm wondering if I'm getting too much air in the engine or something? It's really making me angry, I don't know whats going on. I dumped some fuel/carb cleaner in the tank today but that has helped none. I was thinking that it might be the stupid choke, because I remember before I bought it, the guy telling me the butterfly valve had been rebuilt. Anyway, I was thinking about getting a Holley Truck Avenger 670CFM carb for it. Hoping it would fix the problem, but I dunno. It's making me mad. I'm also thinking it might be the intake. I don't know if anyone else has this on their Bronco. Mine sports the 351 H.O. and it has an intake on it that connects to the firewall and it surrounds the carb. Not the manifold, but an intake. Anyway, anyone know what is up? It's REALLY, REALLY making me mad.

 

Oh yeah, also what would happen if I took off the intake? It's got a few hoses going into it, they don't seem to serve much of a purpose though, I know my truck would be finew/o them, but what exactly are they? Two wires look like they're just for show, heh heh.

 

"Intake" is used to referr to the intake manifold. What you're talking about is more commonly called the "air filter housing", "fresh air duct", or "air cleaner cover". It helps both power & economy by keeping the engine from sucking hot air from the engine compartment. Cooler air is denser and can burn more fuel for more power.

The worst thing you can do is start swapping aftermarket parts on it without KNOWING what the problem is, and it's always easier to diagnose a factory part than an aftermarket. Stick with what you have and figure it out first. Once you have it running right again, THEN think about swapping.

I'd suggest you get a vacuum gauge, a timing light, a compression tester, a fuel pressure tester, a few cans of carb cleaner, some pipe cleaners & old toothbrushes, and some clean rags. See how much vacuum you have at idle; see what your timing is and how steady it is; see what your spark plugs look like and how much compression each cylinder has; see if you have good fuel pressure & flow. If all that checks out, pull the top off the carb & see how much crap is in the bowls, jets, needle valves, floats, & vacuum journals. If it's got some bad parts, kit it.

 

The choke plate should only be closed when the engine is cold. Even then, if it is like my '85 was, it will only go to the closed position after you turn the key on and very lightly touch the gas pedal.

 

I didn't see what year model you have, but I'll assume it's a 84-86 if you have the 351W H.O. The factory Motorcraft (Holley) carb is bad about worn accel. rod, choke, float, etc. There's also several vacuum lines that will give problems. If it's not leaking gas, a rebuild kit is like $15, that's what I'd try first is something is wrong. You can put a white piece of paper in front of the exhaust pipe to see if it's flooding out - turns paper black right away - or if you have a miss/vacuum leak - sucks paper in and out. The intake manifold is UNDER the carb, and the AIR CLEANER/BREATHER is on top. It has a habit of pushing on the ported vacuum fitting on the front top of the intake. If this plastic piece is broken, your EGR valve won't work either. DOn't know about the Truck Avenger, but I've heard of positive results with the Edelbrock 1405/1406 as a replacement. I still have a reman. Holley "bomb" on my 84, but installed an Edelbrock Performer manifold and plan to swap to the 1406 carb when time and $$$ permit!!!