Smoking & no power 1985 bronco II

[fp4]

I have 1985 stock high milage Bronco II. When I got it from previous owner it had been sitting in horse pasture for several years. I charged battery and poured gas down carb and cranked right up, but would only idle. I put kit in carb and would start and rev up. Idle rough & no smoke. No power would only pull itself in 1st & 2nd some. Replaced map sensor and throttle position sensor. Still same thing no power. Now engine smokes like freight train. Previous owner put electric inline fuel pump on and mounted it near original mechanical fuel pump under hood. I hope smoking is seals on valves just don't know. Many cut and spliced wires under hood and I haven't worked on engines since back in 70s. If I could solve lack of power problem I wouldn't mind tackling the heads and what ever else that needed to be addressed. Body in great shape but interior shot. Hope to rebuild and be able to use at hunting camp. Any thoughts on lack of power and smoking would be much appreciated. Thanks. fp4

 

[Shran]

What color smoke? Could be a lot of things. Pull the plugs & read them. Burning oil, steam from bad head gasket? Black smoke, running really rich?

I just picked up a '77 F150 that sat since 1995, supposedly had a good engine - few minutes of run time, lot of smoke and no power led me to find a bad head gasket. Could be anything, you never know with stuff like this.

 

[Thrashingrage]

I'm basically quoting a little bit of personal experience and a lot of my Chilton manual on this. But I would say definitely pull the plugs, and also pick up a vacuum gauge, a compression gauge, and a handy-dandy Chilton manual from your parts store. Plugs, a vacuum test, and/or a compression test will tell you a lot about the condition of your piston rings and valve seals, as well as any vacuum leaks or head gasket leaks - also, that manual will tell you exactly how to read the plugs as well as the vaccuum and compression tests. Also, the TRS tech library has a myriad of great information on these trucks - I'd suggest reading some of the articles there as well. Hope you get your new BII spiffed up and on the road, and welcome!
Josh

 

[fp4]

Thanks for the input. Sorry about the color of smoke. The color is blue and plenty of it. Also I pulled the catalytic converter and it was in great shape and I bolted it back up. Don't mind doing duraspark conversion once I can realize the vehicle is salvageable. The engine starts like new no problem. If it was an old 289 I could handel it with no problem. All these sensors and electronics came along and I was out making a living other wise and I got left behind. Shade tree mechanics like me are lost. Thanks again. fp4.

 

[RonD]

Don't worry too much about "the new engine stuff", common sense is still king in auto mechanics.
Most sensors and parts can be checked with an OHM/Volt meter, or cleaned.

Lack of power has a few sources
Blocked exhaust, you checked cat , did you try driving it with cat unhooked, just to make sure?

Incorrect spark timing, if spark is way past TDC you get little power on ignition of fuel/air

Lack of compression, I would check that next, compression test and leak down if possible, because of the smoke the leak down would tell you if its rings or valve seals.
With engine idling if you remove the oil fill cap or dip stick and get a lot of out flow(blow-by) it is most likely rings, but check PCV and vent tube for blockage.

Low compression could also mean crank/cam timing is off, so timing chain/belt could have slipped or tensioner has failed, idle would be OK but no power when driving.

Incorrect fuel air mixture, blue smoke means oil is in the mix so you know you are not getting correct mix, but it should only be a small loss of power, until spark plugs get fouled and start missing.


Fuel filters are only $10-$15, I might get 2, change it now and then after running a few tanks through it change it again, sitting like that can promote a lot of gunk in the fuel tank.

 

[kimcrwbr1]

While the engine is idleing take a manifold vacuum line and apply vacuum to the egr if the engine stalls the egr is good. You cannot run the engine if any of the sensors are disconnected it will send the computer into limp mode and you will need to reset the computer. Disconnect the battery neg and go through with electrical cleaner and pull all the connectors apart and clean them good and use a dob of dielectric grease to put them back together to protect from moisture, clean the IAT intake air tep sensor in the air filter housing with electrical cleaner or rubbing alcohol. Make sure all the vacuum lines and connectors are correct the common mistake for vacuum lines is the egr bleed line it goes to the large nipple on the bottom back of the air horn on the carb it allows the egr to close so make sure it is clean it pulls filtered air into the egr bleed solenoid the one closest to the heater motor. Press the throttle about haf way down and the choke should fully close, then start the motor you can run it with theair filter out but make sure the sensor in the filter housing is plugged in. Blue smoke sounds to me like valve guide seals you can change them without pulling the heads. In the tech library under 2.8l it explains how. The 2.8 runs really good with all the computer stuff working correct but if you get alot of codes do the duraspark conversion if you dont have to pass a smog test. Good parts are hard to find and real expensive. If you messed with the idle air needles there is a procedure to adjust them correct the engine idle is controlled by the computer you need to disable it. Once the engine is up to temp and the choke is fully open unplug the idle control motor on the bottom front of the carb while the engine is running then adjust the needles for the highest possible rpm. adjut them both a couple times where the rpm only drops when you turn them in then plug the idle motor back in the motor should control engine idle around 700 rpm. GL