1985 Ford Bronco II engine problem, replacement questions?

Question

Two parts --

My '85 Ford Bronco II (2.8L V6, 4WD, carb, manual) starts, idles, and runs fine when the engine is dead cold, or when the engine is fully warm (temp above the 1/3 mark). But when the engine has warmed enough for the needle to come off the bottom but hasn't yet crossed into the normal range, it won't idle or run worth a darn -- it acts like it is only firing on one cylinder and smells like the mixture is extremely rich.

This is a minor problem normally, but in really cold weather it just becomes a complete dog. I can rig it by slapping a cardboard panel across the radiator -- the engine heats all the way up and it works fine.

But I'd really like to know what is HAPPENING to it? This is the 2nd carb that has done this, so I think it must be from the EEC-IV somewhere, maybe a bad sensor?

2nd question: Anyone ever put a 1990's Mazda MPV 2.8L V6 and tranny into a mid-80's Bronco II (my '95 MPV with 165K always runs sweet)? Any advice if so?

Answer 1

First you are probably having a choke problem. It is most likely set too tight or the coolant temp sensor for the computer is not reading properly.
Second Ford and Mazda are in bed together and have been for some years. Since the engine is virtually the same I believe it should bolt in.
The problem is that you are dealing with fuel injection and need the van as a donor so you have the wiring and sensors to make it run.

Answer 2

Having the same problems, but i can't get it to idle, and when i do, i take it for a test, and then the idle is so high that i have to stare all over again.What is the Problem... timing to good wire cap fuel pump all new. carb. was rebuilt about a month ago. there are two high idle screws one under the electric choke, the other is on the throttle body. Any Help would be great.

Answer 3

Sounds to me like either the thermostat is missing, faulty or the wrong temperature for your vehicle and climate. I would replace it first and see what happens.