I have an 84 2.8L 4x4 bronco 2. Last week it started running very rough at startup. It would clear up after a few minutes but still idles rough. This got worse as the week went on. The engine smooths out when I step on the accelerator, but misses badly at idle. First thing I tried is getting the codes, no luck. The code reader shows a solid light and tone as soon as I turn the ignition on. Such fun I can do without, ha ha. Not one to just give up, I noticed an electrical part on the back of the carb looked slightly burned. Oh right, the carb, the tag says e37e aea, chilton says 2150a 2v. The picture for the 2150a 2v looks like the better match. All I can say for sure, at this point, is that its a 2bbl. I tried matching the part wires on the wiring diagram and came up with a choice, either a "barometric pressure sensor" or an "idle speed motor". My symtoms seem consistant with and idle speed motor problem But it would be nice to identify the right part before I pull it all apart again. So, the 2 main questions are: Why does the tester give a solid tone and not do any tests, and what is that sticking off the back of my carb? By the way, the part is cylindrical, 2 inches long, 1 inch across, has 2 wires, held on with 3 screws. Its located on the firewall side of the carb closer to the drivers side.

 

It worked last time I used it. I've tried all approved hook ups, and still get a solid tone. I did change the computer last year, rebuilt actually. Could that be the problem? Bad wire? any less than approved hook ups? It seems I wont get far fixing anything without the codes.

 

Can anyone help with this question, I'm not familar with the 84s design.

 

sorry, its an eec-iv

 

As far as my carb problem goes, it seems all it needed was a good idle mixture adjustment. Didnt fix it completly, but its idling smoother and the mileage seems to have improved. Anyone else notice that it takes a while (3 days normal driving) for the computer to notice any changes?

 

Is there an extra wire near the code reader test port? Sometimes a jumper is needed to compensate for different units. Check your code reader manual on this jumper wire

Mark

 

That part would be a feedback solenoid. Let me see if I can try and explain what it does... uh... nope, I can't exactly figure out what my shop manual is trying to say but I think it has something to do with metering the mixture.

 

Now that you mention it, I did find an extra wire. The manual said there should be 2 connectors, a 6 pin and a single pin. I found a second single pin in the same area. I'm a bit scared to mess too much with the wires though. I cant find any reference to the second single pin.

 

LOL, same problem I have with the manual. I tracked the problem to that solenoid too. Hard to say for sure if thats the problem. I need codes!!! What shop manual are you using? I found a manual through here that says its for the b2 exclusively. It says it has sections on my 2.8L. That would be nice if true. Chilton is confusing more than it helps.

 

it sounds like you have a vacumm leak, I have an 84 as well and when this happens it seems like a vaccum line could be loose or disconnected. First check the vaccum connection from the transmission to its hookup near the passanger side back part of the carb. Check that hose and see if it is cracked or not hooke dup completley. Also where the transmission vaccum line hooks up (at the passenger back side of the carb.) there it a three split where it hooks up, one for the tranmission vaccum line, one from the front of the air cleaner assembly, and another that has a little nipple on it where the cruise control module would go. Check these lines as well, my truck has a problem with knocking off the nipple the cruise control vaccum hole, and this causes my truck to run very rough at eventually causes it to stall if I do not give it gas. if this doesnt fix the problem go by a carb. rebuild kit and start rebuilding it, or buy a new carb. I have seen new rebuilt motorcraft 2150 2v feedback carbs on line for about $200 and are flow tested. They take about a 1/2 hour to install.

 

Another possible problem that found out with my 84 BII was leaky manifold gaskets. My BII had similiar problems as you have mentioned, though not as bad. Carb was recently rebuilt by previous owner, tried the squirting of WD40 along the manifold to head joint, no change. Then I noticed that the manifold gasket actually is under the valve cover, similiar to the FE V8's. When I removed the valve covers and intake manifold, I found that the intake gasket had harden up something fierce and allowed engine crankcase gasses and some engine oil to leak into the cylinders causing a lean condition, especially at idle. The spark plugs showed a lean condition was occuring. Replacing the intake gaskets gave me back a smooth idle and a substantial increase in power not to mention better gas mileage.