94 F150 I6 Hard Start Problem
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From: ms
94 F150 I6 Hard Start Problem
Ok I am working on my uncles 94 F150. I have two major problems that I can't get figured out.
1. A couple of weeks ago he contacted me about his truck not wanting to start. After I looked it over I cleaned the throttle body and IAC. The truck started cranking fine. Last week he called and said that it was acting up again. Now when you go to crank the truck the engine will spin over but won't start unless you mash the gas pedal all the way to the floor. When it does crank it blows black smoke out the tail pipe and runs rough for a few seconds. It also blows black smoke when revved. I found the distributor cap had some corrsion on the contacts and the plugs were very black. I also found that the post on the coil had been eaten away from arcing. So I replaced the plugs, wires, cap, rotor, coil and even the pickup coil in the distributor. I also cleaned the injectors and am still having the hard start problem with black smoke.
2. I have a scanner from the local chain parts store that will read the codes on an EEC-IV Ford system but mine is not communicating with the computer. Is there a fuse or something that would cause the plugs not to work? Or is my scanner just not communicating for some reason?
Sorry for the long post but I was trying to be very informative. Thanks in advance for any advice.
droff85
1. A couple of weeks ago he contacted me about his truck not wanting to start. After I looked it over I cleaned the throttle body and IAC. The truck started cranking fine. Last week he called and said that it was acting up again. Now when you go to crank the truck the engine will spin over but won't start unless you mash the gas pedal all the way to the floor. When it does crank it blows black smoke out the tail pipe and runs rough for a few seconds. It also blows black smoke when revved. I found the distributor cap had some corrsion on the contacts and the plugs were very black. I also found that the post on the coil had been eaten away from arcing. So I replaced the plugs, wires, cap, rotor, coil and even the pickup coil in the distributor. I also cleaned the injectors and am still having the hard start problem with black smoke.
2. I have a scanner from the local chain parts store that will read the codes on an EEC-IV Ford system but mine is not communicating with the computer. Is there a fuse or something that would cause the plugs not to work? Or is my scanner just not communicating for some reason?
Sorry for the long post but I was trying to be very informative. Thanks in advance for any advice.
droff85
Elder User
Joined: Dec 2003
Posts: 660
Likes: 3
From: Northern California
Ok I am working on my uncles 94 F150. I have two major problems that I can't get figured out.
1. A couple of weeks ago he contacted me about his truck not wanting to start. After I looked it over I cleaned the throttle body and IAC. The truck started cranking fine. Last week he called and said that it was acting up again. Now when you go to crank the truck the engine will spin over but won't start unless you mash the gas pedal all the way to the floor. When it does crank it blows black smoke out the tail pipe and runs rough for a few seconds. It also blows black smoke when revved. I found the distributor cap had some corrsion on the contacts and the plugs were very black. I also found that the post on the coil had been eaten away from arcing. So I replaced the plugs, wires, cap, rotor, coil and even the pickup coil in the distributor. I also cleaned the injectors and am still having the hard start problem with black smoke.
2. I have a scanner from the local chain parts store that will read the codes on an EEC-IV Ford system but mine is not communicating with the computer. Is there a fuse or something that would cause the plugs not to work? Or is my scanner just not communicating for some reason?
Sorry for the long post but I was trying to be very informative. Thanks in advance for any advice.
droff85
1. A couple of weeks ago he contacted me about his truck not wanting to start. After I looked it over I cleaned the throttle body and IAC. The truck started cranking fine. Last week he called and said that it was acting up again. Now when you go to crank the truck the engine will spin over but won't start unless you mash the gas pedal all the way to the floor. When it does crank it blows black smoke out the tail pipe and runs rough for a few seconds. It also blows black smoke when revved. I found the distributor cap had some corrsion on the contacts and the plugs were very black. I also found that the post on the coil had been eaten away from arcing. So I replaced the plugs, wires, cap, rotor, coil and even the pickup coil in the distributor. I also cleaned the injectors and am still having the hard start problem with black smoke.
2. I have a scanner from the local chain parts store that will read the codes on an EEC-IV Ford system but mine is not communicating with the computer. Is there a fuse or something that would cause the plugs not to work? Or is my scanner just not communicating for some reason?
Sorry for the long post but I was trying to be very informative. Thanks in advance for any advice.
droff85
To me, it sounds like you've got a PCM that's failing........
Here's a link of what "could be" going on.
Click here:A9x ECM's (and same years ECM's) Failures Due to Age
"If" the grounding circuits within the PCM are or have been corrupted by capacitor leaking/failure, the PCM "could" fail to communicate with a code reader/scanner, no/random grounding of injector pulse rate(s), inability to store trouble codes, random missfires/stalling, flooding problems......just to name a few things.
And if you like to read, this poster (Guy) had the problem of his PCM not communicating with his scanner. https://www.ford-trucks.com/forums/1...st-module.html
I'd try removing the PCM and give it a look inside.
If everything looks good inside (no capacitor leakage/burnt components) then go from there.
To me, based upon your symptoms, that's where I'd start.
And, my 94' PCM had the capacitor leaking problem.
It took a few bucks and a visit to Radio Shack to repair mine.
Bob
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From: ms
Ok figured something interesting out this afternoon. I had to move the truck and when I cranked it everything was fine but the check engine light was on. I decided to take the truck down the road and once I noticed the thermostat opening, showing movement on the temp gauge, the check engine light went off and the engine started showing the black smoke again. I decided to shut it off and try cranking it again and the hard star was present again. While it was cold it started right up with no black smoke. Does this help?
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