bronco ii acceleration problems HELP!!!!!!!

boredom zero · Mar 3, 2011

I have an 85 bronco ii 4x4 and it has many flat spots in the acceleration that seem to be intermittent. i was looking at the tech center and it seems like it could be a few different things like, the TFI, the EEC, or maby the TPS but i have no idea.i also checked all the wires for a possible grounding or shorting issue but everything seems to be fine and i just replaced the TFI about 1000 miles ago and everything else is pretty old but worked fine until a couple of nights ago. the problem occurs when im starting to accelerate and when i lift off the pedal to sort-of coast down hills. it seems to buck like crazy when im holding a steady speed from anywhere to 25-65 and when i down shift to fourth when going up hills it just loses power and speed and no matter how hard i push the pedal it does nothing. at first i thought it was a fuel issue but everything in that system is fine and the carb is freshly rebuilt. the only thing it feels like that has ever happened was when i ran out of gas and it was miss firing because of lack of fuel, but its got a full tank and the filters arent that old. if anyone has any ideas or has happened to them before please help because it's driving me crazy, thanks for your help if you can

gribly · Mar 3, 2011

Plugs and wires?

The_Dealer · Mar 3, 2011

I'd cjeck the plugs and wires. Sounds like duraspark time. I got tired of messing with the tfi and eec crap and went dspark and never looked back. U can make a metering block and use yóur stock carb

boredom zero · Mar 3, 2011

yea id like to do that and it seems simple enough but i dont have the money right now and jus need it for commuting rite now but i did change the plugs about 1000 iles ago when i put new heads on and the wires probably have a little more than 5k on them. im gunna check the TPS and try to trouble shoot this piece but duraspark is deffinatlly down the road.

boredom zero · Mar 4, 2011

i checked the wires they are all in real good shape and the plugs im sure are good because they have very low miles so it's got to be ignition or something weird with the fuel. i also checked the TPS and the OBD 1 sensor and plug with a volt meter and got no movement in the needle on the TPS and the OBD was the same read out as the battery. i printed out the tech info on checking the TPS and applied it and could get squat maybe i was doing it wrong but i dont understand how it gets power if i have to unplug it to check it. as far as the OBD 1 i couldn't make heads or tales out of the reading because the tech info says it will do one thing and it does nothing of the sort. i mite just have to find a way to get it to a shop and have if fixed or sell the damn thing because this is getting ridiculous it seems every month something goes wrong and its just not worth the stress. any ideas or inside knowledge on doing this sort of thing yourself would be a great help, thanks.

gribly · Mar 4, 2011

My Mazda 323 that I had for a very short time before I gave it to my sister did this due to the distributor cap and rotor being worn down. I also had a similar thing happen to my '93 Escort, and it was the coilpack. I'd check your coil next.

kimcrwbr1 · Mar 4, 2011

When it is idling unplug the idle control motor then adjust the air fuel needles for the highest rpm or vacuum pressure then plug the motor back in. Disconnect the battery for 1/2 an hour and then run it for 20 mins and see how it runs. How old are the plug wires and PCV if you dont know change them now with plugs cap and rotor.

The_Dealer · Mar 4, 2011

I spent maybe 250 on my dspark, if u can find jy parts it woulda been cheaper. I got all new stuff though

boredom zero · Mar 4, 2011

i pulled the dist. cap and everything looks good underneath there was no dust and it was very clean. i started the car and ran it for a minute tinkering with the needles and i got it running as smooth as can be as far as that goes. so i was thinking what if i unplug the TPS just for shits and giggles with it still running, so i did and all of a sudden it was running smoother it seemed like it was normal. with it plugged in the motor vibrates hella bad and shakes, with it out its runs smooth and a little bit higher rpm. with it unplugged i took it for a drive and it seemed like i had fixed the problem for a couple of minutes and the i pulled out of a stop light and it was back but not as bad. it also seemed more like when it was at higher rpm maybe around 2500 and up the problem occurs. i also checked the coil and it seems fine had a little bit of power steering fluid on it but nothing to major that would make it not work.

bronco ii acceleration problems HELP!!!!!!!

boredom zero

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gribly

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The_Dealer

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boredom zero

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boredom zero

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gribly

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kimcrwbr1

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The_Dealer

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boredom zero

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