Well my BII has been running well since I changed the clutch but now… To day was the first day that I drove more than 5-6 miles. I’ve just been using it to go to work and back home every couple of days. Today I had a Dr. appt. after work so I drove the BII (about 10-15 miles).

I’ll let you know now this is an ‘86 manual 4WD with a 2.9 EFI engine.

It drove there fine until I tried the A/C then it kept stalling on me. I just turned off the A/c and then had no problems. I did notice that the temp gage never registered. I know that I need a new thermostat (old one leeks). I am planning on replacing it this weekend. I figured that my temp gage wire came disconnected and that I would look at it this weekend when I replaced the thermostat.

Any ways when I went to leave the Dr. office the truck didn’t want to start. When it did it ran very rough and then stalled. At first I thought it might have something to do with the fact that I was parked on the side of a hill so I let the truck roll back onto the flat. I still had the same problem. I checked under the hood and noticed a hose [from some type of canister on the drivers side between the fender and radiator to the throttle linkage / intake area] was disconnected so I connected it. I also noticed a faint sweet fuel smell (almost like a flooded carburetor). I waited a few minutes and tried to start it again with out any success. I was finally able to get it started by letting the starter motor run for quite a while and pumping the gas. When it first started running it sounded good for about 10-20 seconds but then it quickly started running very rough. I was able to drive home but had to go through the process of the truck stalling and trying to get it restarted about 4 times in 10-15 miles. Once the truck was driving at a constant speed any where from 35-65 mph it ran sort-of okay but accelerating was very rough with little power at all and changing gears was murder.
So I guess along with the thermostat this weekend I’ll also be changing the fuel filter(s), air filter, spark plugs and wires, PCV and all that other good stuff that I’ve been putting off.

What are your opinions on what could be wrong with my truck and what I need to be looking at. Thank you in advance.

 

i would start by pulling codes and checking the fuel pressure at the fuel rail..it could be a number of different things causing the problem..so by pulling codes that may lead us in the right direction to try and track the problem down

 

my friends 86 manual BII had the exact same problem as yours. Out of no where it started running really rich and rough and his would barley accelerate at all or even run for that mater. After all my attempts to fix it for him in vain we took it to a shop that only deals with fords and had them look at it. It ended up being a blown fuseable link and also the pickup in the distributor was shot. This sounds exactly like his problem and his truck was not throwing any codes for it. Just some food for thought.

 

You know, that sounds really familiar. My Bronco II, 1988 XLT, Auto, 2.9 V-6, has a problem of an intermittent stutter, loss of power, but seems to clear up if I just push the gas on down towards the floor. It doesnt do it all the time, but usually right after a startup. I pulled codes, and it had a code saying the O2 sensor was out of range. I havent changed it yet, but does this sound possible to be the culprit? Thanks for any advise.

 

The disconnected hose was from the carbon / evap cannister that is part of the emissions system and is interconnected to the gas tank, so that is why you had the fuel smell. As far as it running rough, it could be that the carbon/evap got bombarded with fuel instead of vapors, not to mention the system could have decided to run lean on you, then re-connecting it may have made it rich or some such. I would pull codes first, then the next step is probably the distributor pickup and fusible links, as Candadian mentioned. You may also want to check all of your electrical connections as well as vacuum hoses, and to a test on your TFI module. Another contributing factor may be the MAP sensor, if all of your vacuum lines check out and you have no vacuum leaks. Yet another factor could be the O2 sensor. There are a lot of things that can cause these symptoms, so check everything while you're there, and pull codes. Hope this helps.

 

Thank you,

I can see that y'all have already saved me a lot of hassle and searching. Now how do I pull the codes?

 

If you don't have a code reader (digital lcd display type preferred, but there is another one that uses a light), you can use the procedures explained in the "Read First: Technical Information" thread at the top of the forum. The link is under "Emissions", if I remember right. I prefer to use the Equus (Actron) #3145 Digital Code reader for Fords, which sells for $30 at most parts stores. Takes a lot of the guess work out of counting flashes of test lights, movements of analog multimeters, or flashes of the check engine light. Whichever best works for you.

 

I just went thru that with mine, it would just all of a sudden start running rich, and black smoke. I could let off the gas for a sec, then give it about 3/4 throttle. and it would clear up and run great for a while. It was the O2 sensor.

 

I'm pretty sure thats not whats happening here. I get no smoke and if I let off the gas for a second the truck'll die.

 

I would do a quick look at your spark plugs, they will tell a huge story of what is happening inside your motor. If they are black and sooty the truck is running rich, this can help us narrow down if you are getting enough fuel or to much, or if it is perhaps it's spark related. Just pull them out and maybe give us a shout it will solve the problem better.

 

I got a code readder this morning. however I don't think That I'll need it. I tried to start the truck before I did any thin and it started up great and ran alright a little rough but thats compaired to the taurus I've ben driving for the past few days that you can hardly hear it running at all. Because my temp gage wasn't working and I have a coolant leak at the termostat housing I'm assuming that the problem was related to overheating. I will change the termostat, fix the leak, change the filters, sparkplugs, wires etc... then try to pull codes and let you all know what is up. Thanks again

 

I replaced the thermostat and fixed the coolant leak. I also replaced the air filter which didn’t look to bad but was dirty. The air intake manifold was extremely dirty. I sprayed some carb cleaner in, the gum and varnish that came out astonished me. It was the color of used motor oil and was just starting to thin and clear up when the can was empty.

I pulled a plug and compared it to the pictures on the back cover of my Haynes manual. It looks like a cross between the “TOO HOT” and “HIGH SPEED GLAZING” examples. (My wife thinks it looks more like the “TOO HOT” I think it looks more like the “HIGH SPEED GLAZING”.)

 

It'd be interesting to see a picture of one of the plugs. When were they replaced last? Wondering if it's a situation where the last time they were changed, it was in a different climate area or something. I have seen differences between places as far as recommended part #s, but -normally- it's a vehicle/engine-specific thing. Maybe do a lookup online to see what part # is listed at your local Advance/Checker/Shucks/Kragen, AutoZone, CarQuest, etc. and compare it to the plugs that are in your truck now. That'll usually tell you whether or not it's too hot a plug or if it's high-speed glazing. Hopefully, you made some progress on getting it back in better running condition. Keep us posted.

 

I don't know how to post photos sorry. I ran the codes. I got no codes during the Key On Engine Off Test. During the Key On Engine Running test the timming was at about 12 Degrees and I got the following codes: #25 EGR valve, #77 operator error, and #25 (I thing the #25 was because of the #77). I'm not sure what the engin RPM was because my Truck's Tach is not working and I don't know how to hook up my diagnostic tach to this truck's coil.

 

I believe the green wire on your coil is the one for the tach. Yeah, operator error usually happens when you don't shift the steering wheel, step on the brake, then with your foot go wide open throttle and let off. I don't remember if I got a code 25 for the EGR valve when I didn't do one properly or not. KOEO results with no codes usually means there's nothing faulting or at least nothing throwing a code that stays in the computer's constant memory. Okay, your timing was at 12 degrees... with the SPOUT connector in or removed? If it's with it in, then something tells me timing is off, because I think it's supposed to auto-adjust between 23 and 32 deg. BTDC or some such. I'd have to look at the procedure to test / check that. Even with the connector out, it should be at 10 degrees BTDC, at least that is the joe-neric base timing setting. The "correct" setting should be on the emissions label under your hood. I'm also wondering how far off your spark plug gaps were, because going too wide will also cause issues, especially decreasing the life span of your spark plug wires, cap, rotor, and sometimes coil.