1986 Ford Bronco II 2.9L sluggish

[mark5bronco]

Hello, I bought another 1986 Bronco II the other day. it had been sitting for a while and would not start. i dropped the gas tank and the fuel pump inside fell apart. i installed a new pump, regulator and fresh gas. it will crank barely with a little help but idles like it is suffocating and wanting to die. if i spray a little starting fluid--the rpm will rise so it makes me think that it is starving for fuel but that was my guess. I checked the plugs and wires. and plenty of pressure at the fuel rail. I took off the top intake and the erg was totally clogged up on the intake. I have no idea what has been done to the vehicle before i got it--i got it from a guy that bought it from another guy and so on--- but i did find an old distributor, plugs, cap, wires, rotor, fuel injectors, and many other parts in the bronco II as if they were trying to fix it. I know the upper intake was taken off cause they ran the wire harness over the intake rather than through the openings. any thoughts on which direction I should go to identify the problems? thanks mark

 

[franklin2]

If they changed the distributor, more than likely they did not know the special procedure for setting the timing, which would make it sluggish. I would check the timing first.

 

[RonD]

+1 ^^^ Spark timing would be first on the list

Also run a can of Seafoam in the gas tank or similar injector cleaner

Does it run better after it warms up and O2 sensor is on line?
O2 sensors last 100k miles or 12 years which ever comes first, they simply run out of chemicals to detect oxygen in the exhaust, when that happens they show Lean, so computer runs engine Richer, which would cause sluggish performance and poor MPG

 

[mark5bronco]

Thanks guys, I haven't checked the timing yet. I agree I need to check it. I did put new gas and sea foam in it as well. it will idle but kinda rough until you raise the RPM. at about 1800 RPMs it seems to level out a little but still feels a little sluggish. The ERG was totally stopped up when i took the intake off--not sure if that will change anything. I'm not sure about the O2 Sensor--is it located on the Catalytic Converter? By the way, the catalytic converter was off the bronco. i took it to the muffler shop and he said it was ok and not stopped up so i put it back on--not sure why they took it off. But aren't the O2 sensor hard to get off since they are kinda welded on due to the heat? thanks again for your responses.

 

[alwaysFlOoReD]

86 has one o2 sensor located ahead (engine side) of the cat. Up above where it's a pain to get to....

 

[franklin2]

Thanks guys, I haven't checked the timing yet. I agree I need to check it. I did put new gas and sea foam in it as well. it will idle but kinda rough until you raise the RPM. at about 1800 RPMs it seems to level out a little but still feels a little sluggish. The ERG was totally stopped up when i took the intake off--not sure if that will change anything. I'm not sure about the O2 Sensor--is it located on the Catalytic Converter? By the way, the catalytic converter was off the bronco. i took it to the muffler shop and he said it was ok and not stopped up so i put it back on--not sure why they took it off. But aren't the O2 sensor hard to get off since they are kinda welded on due to the heat? thanks again for your responses.

EGR is best left blocked off till you get it sorted. It can cause a check engine light and maybe some slight pinging in the engine if it's not working, but it will not make it sluggish. It's worst failure mode is not closing off, which will give you a rough idle and stalling. So being plugged can be a good thing sometimes.

O2 sensor is going to have no affect till the engine warms up. The computer does not even look at the O2 sensor after the engine is started cold. You usually have to drive it a couple of minutes before it starts using the O2 sensor. So that would be a good test, see if it's sluggish right from a cold morning start. Or you could just unplug the O2 sensor and see what it does. It will look for info from the O2 sensor, and when it doesn't get any, it will set a code for the sensor and then start fueling the engine from the data tables stored in the computer memory at the factory. That would be a interesting test also.

 

[mark5bronco]

thanks--i havent put things back together yet to see if any changes. it is sluggish as soon as you start it up--if you raise the RPM--it does seem to change from sluggish to a little less sluggish--really it feels like it is running like off of 4 of the 6 spark plugs--but i did put new ones in it and new wires. thanks for the intel on the ERG

 

[mark5bronco]

86 has one o2 sensor located ahead (engine side) of the cat. Up above where it's a pain to get to....

thanks i will look at it. when i bought the bronco the cat was removed and in the back of the vehicle--but the muffler shop said it was not stopped up

 

[Cees Klumper]

X2 on the ignition timing (remove the 'spout connector' to set timing) but also it could be worn fuel injectors. Rebuilt set around $100, find the original Bosch rebuilts, not cheap new ones.

 

[4x4prepper]

I once had to do a parking lot repair and pull the distributor and between watching my back and everything else, I got it 180 degrees off. It started, but ran terrible.

Check to see if you have one of those fake fuel filter canisters (black plastic) by the gas tank, on the driver's side. They can cause problems.

Change the fuel filter, $15. The high pressure pump under the driver's door can go bad and the lines can get clogged. Disconnect everything from the pump, and try blowing some air through to the engine (obviously disconnect at engine) and then try the tank lines. You might have to run carb clean through the lines. They can get pretty packed up with the yellow gunk from bad fuel.

 

[franklin2]

I have never seen a engine run 180 out? That "fake" plastic fuel filter housing is the fuel reservoir. It keeps the high pressure pump supplied with fuel at all times. It's a little storage tank. Some had a filter, some didn't.

 

[SenorNoob]

Not a truck, but I've seen three wheeler run backwards.

 

[dirtymike]

running 180 degrees out, wow