1985 300 lacking power
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1985 300 lacking power
i have a 1985 ford f-150 with a 300 inline 6, c6 tranny and 3.08 rear.
my truck seems to be lacking power. when travelling on a level it does not accelerate as fast as it used to. when travelling up hill without moving the gas pedal the engine gets drawn down then picks it self back up then gets drawn down again.
i recently rebuilt the carburator, serviced tranny, new air filter, new fuel filter, new rear end oil, new spring kits, new fuel pump.
i cant figure this out can someone please help me.
thank you. Brian
my truck seems to be lacking power. when travelling on a level it does not accelerate as fast as it used to. when travelling up hill without moving the gas pedal the engine gets drawn down then picks it self back up then gets drawn down again.
i recently rebuilt the carburator, serviced tranny, new air filter, new fuel filter, new rear end oil, new spring kits, new fuel pump.
i cant figure this out can someone please help me.
thank you. Brian
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From: Denver Metro Area, CO
Computers were inside the cab, electronic ignition was under the hood on the driver's side wheel cover.
In 1985, the 6-banger & 302 had feedback (computer-controlled) carbs, the predecessor to EFI which began in 1986 as I recall.
I seem to remember the transition to unleaded fuel beginning in the early-mid 1970s in all of US, Canada & Mexico.
The 351W 4V V8s were still DS2 (no computer) as were the 460s. Not sure about any 2V 351Ws.
I can't imagine a 1985 6-banger coming out of the factory built to run on leaded gasoline, that stuff was pretty damn close to "no longer available" by that point.
What is your truck's VIN? THAT will tell us definitively, post a picture of the Certification Label on the driver's side door jamb.
Failing that, the VIN at the bottom of the windshield on the driver's side.
As will the Calibration Code, give us that information, too. Should be on a sticker on the front of the passenger side valve cover.
Pictures?
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ok as soon as i figure out how to upload photos i will. but i am positive it was built for leaded fuel. it has been in my family since it rolled outta the factory. it was built in oakville ontario. zero emission controlls on it, no cats, no polution pump and no charcoal can.
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One way to tell what you have; Does your distributor have a vacuum line going to it and the vacuum can sticking out where it hooks? If it does, then you are correct it doesn't have a computer, or the truck has been converted along the way at sometime.
If you have no place for a vacuum line to the distributor, it does have a computer.
The reason we are doubting you is because this is a very common problem with these year six cylinder engines, and there are very many owners like you who have to make a decision of what they are going to do, which is either embrace, learn, and keep the computer system going, or ditch the computer system and go with the old school dist and carb system.
Once you write back in with verification, we can then troubleshoot more accurately your problem.
If you have no place for a vacuum line to the distributor, it does have a computer.
The reason we are doubting you is because this is a very common problem with these year six cylinder engines, and there are very many owners like you who have to make a decision of what they are going to do, which is either embrace, learn, and keep the computer system going, or ditch the computer system and go with the old school dist and carb system.
Once you write back in with verification, we can then troubleshoot more accurately your problem.
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From: Northern California
1983 and older could have the computer bolted on the inner fender next to the ignition module. Like my 1981 for example.But in this case, I believe he's talking about the ignition module itself. Blue relief grommet. It's either been swapped as US models had TFI-IV EEC-IV in 1985, or it's a foreign model from latin america somewhere.
We are going to need pictures to see what we are dealing with.
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From: Northern California
All American built 1985 F-150s with a 300 six came with a TFI-IV EEC-IV computer system from the factory.
Can you post the first three digits of the VIN number.
Since you have a vacuum advance we can assume you dont have TFI-IV ignition.
You have one of the other ignition systems, that's either been swapped into the truck at a later date, a hybrid system due to this change, or a foreign model.
EDIT: Just saw it was built in Oakvale Ontario. Didn't catch that before.
If everything is factory it has a DS-II system. Canada Built models go by different rules than American or latin American built trucks.
Can you post the first three digits of the VIN number.
Since you have a vacuum advance we can assume you dont have TFI-IV ignition.
You have one of the other ignition systems, that's either been swapped into the truck at a later date, a hybrid system due to this change, or a foreign model.
EDIT: Just saw it was built in Oakvale Ontario. Didn't catch that before.
If everything is factory it has a DS-II system. Canada Built models go by different rules than American or latin American built trucks.
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franklin i replaced the plugs about 3 months ago. i will pull them anyway and take a look. personally i think its spark timing but i dont have a timing light to check this. i know the vacuum advance is working because i can see it move.
when i replaced the fuel pump it did seem to get a little better. before that it would seem as if i was towing something when going uphill. almost felt like something was dragging.
when i replaced the fuel pump it did seem to get a little better. before that it would seem as if i was towing something when going uphill. almost felt like something was dragging.
Post Fiend
Joined: Jul 2004
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From: Northern California
Look at the things you have done to the truck first.
Most notably I would check:
1: fuel mixture adjustment.
2: Timing
3: "service transmisson and rear end" what gear oil did you use. Thicker than normal oil will increase drag, etc...
Most notably I would check:
1: fuel mixture adjustment.
2: Timing
3: "service transmisson and rear end" what gear oil did you use. Thicker than normal oil will increase drag, etc...
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i dont think it is the carb adjustment but it is possible.
timing is my guess to but i need a timing light.
i serviced the transmission trying to fix the problem but it did nothing. the rear end oil was changed long before it started acting up. i used 80w synthetic gear oil.
the truck ran fine till one day it just starting to act up.
thank you all for helping me
timing is my guess to but i need a timing light.
i serviced the transmission trying to fix the problem but it did nothing. the rear end oil was changed long before it started acting up. i used 80w synthetic gear oil.
the truck ran fine till one day it just starting to act up.
thank you all for helping me