running issue
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Senior User
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running issue
hey guys, got a running issue.
its 85 f150 300 6'
she will start, but runs really rough and when i warms up, she will not start. it has new plugs,wires cap and rotor,me and my dad think its the condenser. or a stuck valve cause if you take a dollar and stick it in front of the exhaust it will suck it up in the exhaust
its 85 f150 300 6'
she will start, but runs really rough and when i warms up, she will not start. it has new plugs,wires cap and rotor,me and my dad think its the condenser. or a stuck valve cause if you take a dollar and stick it in front of the exhaust it will suck it up in the exhaust
FTE Legend
Joined: Nov 2015
Posts: 30,935
Likes: 4,123
From: Angier, NC
That truck should have the feed back system.
First thing I would do is a compression test to make sure the motor is good after the $1 bill trick.
Then I would pull codes there are posts how to do that.
Dave - - - -
First thing I would do is a compression test to make sure the motor is good after the $1 bill trick.
Then I would pull codes there are posts how to do that.
Dave - - - -
Lead Driver
Joined: Jul 2009
Posts: 6,477
Likes: 19
From: Sheffield, AL
RadioControlGuy85,
No condenser, due to electronic ignition. When your dad was growing up [me, too], ignition systems had points and a condenser.
FuzzFace2 is correct, regarding the feedback system, unless converted at some time.
Check for vacuum leaks. These engines do not like vacuum leaks and will run horribly. When starting "cold", the carburetor causes the mixture to be rich, which helps mask the vacuum leak(s). Once warm, a vacuum leak will cause a lean mixture and the engine will run worse.
No condenser, due to electronic ignition. When your dad was growing up [me, too], ignition systems had points and a condenser.
FuzzFace2 is correct, regarding the feedback system, unless converted at some time.
Check for vacuum leaks. These engines do not like vacuum leaks and will run horribly. When starting "cold", the carburetor causes the mixture to be rich, which helps mask the vacuum leak(s). Once warm, a vacuum leak will cause a lean mixture and the engine will run worse.
Lead Driver
Joined: Nov 2013
Posts: 7,178
Likes: 1,174
Some more background on the truck would help. Specifically, how long have you owned it and when did the problem start? My first thought was two plug wires got swapped during a tuneup. But if the problem just happened out of the blue, and new plugs, wires, etc. were no help, I'd suggest a compression test, as previously recommended.
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we have owed it for at least 15 years, or more, i have never seen it run this bad, it was running great and strong up till couple weeks ago, then it started doing this,
it will start right up, but runs like crap, you can smell it running really rich the tach shows it idling at 0 or below 0, when you give it gas its sounds like its missing, it will shake the truck. also will idle for about 5-10mins then shut off.
like i said
it has msd cap,rotor, and wires, e3 spark plugs,
yea i seen that the (condenser). didnt know it was for the radio,
while running if you pull one of the wires off the spark will jump to the plug and it has a nice bright blue spark.
o for got to mention, im pretty sure someone got rid of the computer,
it will start right up, but runs like crap, you can smell it running really rich the tach shows it idling at 0 or below 0, when you give it gas its sounds like its missing, it will shake the truck. also will idle for about 5-10mins then shut off.
like i said
it has msd cap,rotor, and wires, e3 spark plugs,
yea i seen that the (condenser). didnt know it was for the radio,
while running if you pull one of the wires off the spark will jump to the plug and it has a nice bright blue spark.
o for got to mention, im pretty sure someone got rid of the computer,
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Senior User
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what ever it is, its getting worst fast, just went out to move it. and she wont move, just stalls out when you let the clutch out to try to move,
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Post Fiend
Joined: Feb 2008
Posts: 5,831
Likes: 121
From: St Albert, Alberta
Duraspark II Coil testing
Disconnect coil and remove high tension lead
Check primary resistance between + (positive) and - (negative) coil terminals. Resistance should be 1.00-2.00 ohms If resistance is not within this range replace the ignition coil.
Check secondary resistance between coil - (negative) terminal and high tension lead terminal Resistance should be between 7000-13,000 ohms. If resistance is not within this range replace the ignition coil.
Pick up Test.
Disconnect the distributor pick up by the distributor.
Test resistance between the Orange and Purple Wire it should be 400-800 ohms If outside this range replace pick up.
Test resistance between the Orange to ground and the Purple to ground both should be be more than 70K ohms. If not replace pick up.
Disconnect coil and remove high tension lead
Check primary resistance between + (positive) and - (negative) coil terminals. Resistance should be 1.00-2.00 ohms If resistance is not within this range replace the ignition coil.
Check secondary resistance between coil - (negative) terminal and high tension lead terminal Resistance should be between 7000-13,000 ohms. If resistance is not within this range replace the ignition coil.
Pick up Test.
Disconnect the distributor pick up by the distributor.
Test resistance between the Orange and Purple Wire it should be 400-800 ohms If outside this range replace pick up.
Test resistance between the Orange to ground and the Purple to ground both should be be more than 70K ohms. If not replace pick up.
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Thread Starter
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Senior User
Joined: Nov 2012
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Duraspark II Coil testing
Disconnect coil and remove high tension lead
Check primary resistance between + (positive) and - (negative) coil terminals. Resistance should be 1.00-2.00 ohms If resistance is not within this range replace the ignition coil.
Check secondary resistance between coil - (negative) terminal and high tension lead terminal Resistance should be between 7000-13,000 ohms. If resistance is not within this range replace the ignition coil.
Pick up Test.
Disconnect the distributor pick up by the distributor.
Test resistance between the Orange and Purple Wire it should be 400-800 ohms If outside this range replace pick up.
Test resistance between the Orange to ground and the Purple to ground both should be be more than 70K ohms. If not replace pick up.
Disconnect coil and remove high tension lead
Check primary resistance between + (positive) and - (negative) coil terminals. Resistance should be 1.00-2.00 ohms If resistance is not within this range replace the ignition coil.
Check secondary resistance between coil - (negative) terminal and high tension lead terminal Resistance should be between 7000-13,000 ohms. If resistance is not within this range replace the ignition coil.
Pick up Test.
Disconnect the distributor pick up by the distributor.
Test resistance between the Orange and Purple Wire it should be 400-800 ohms If outside this range replace pick up.
Test resistance between the Orange to ground and the Purple to ground both should be be more than 70K ohms. If not replace pick up.
do you have any walk through on this? cause i have no clue what any of that is.
Post Fiend
Joined: Feb 2008
Posts: 5,831
Likes: 121
From: St Albert, Alberta
The tools you will need are a DVOM, Digital Volt Ohm Meter. You can also use an analog one if you do not have a DVOM
If you are unsure how to use one there are lots of tutorials on You Tube.
The first test is to check the resistance on the primary winding on the coil.
You will disconnect the power leads to the coil and check the resistance between the terminals. They are marked + and - or Pos and Neg. If not the green wire should go to the neg.
You then do the same test between the center terminal on the coil (high tension lead/ coil spark plug wire) and the negative terminal.
The pick is the bit in the distributor that picks up the single in the distributor to trigger the ignition box to fire the coil..
There should be 3 wires coming from the distributor housing Purple Orange and Black The black is ground the other 2 are the signal wires. About 4" from the distributor there will be a plug this a good place to unplug the harness to test for the resistance between the purple and orange wires.
If you are unsure how to use one there are lots of tutorials on You Tube.
The first test is to check the resistance on the primary winding on the coil.
You will disconnect the power leads to the coil and check the resistance between the terminals. They are marked + and - or Pos and Neg. If not the green wire should go to the neg.
You then do the same test between the center terminal on the coil (high tension lead/ coil spark plug wire) and the negative terminal.
The pick is the bit in the distributor that picks up the single in the distributor to trigger the ignition box to fire the coil..
There should be 3 wires coming from the distributor housing Purple Orange and Black The black is ground the other 2 are the signal wires. About 4" from the distributor there will be a plug this a good place to unplug the harness to test for the resistance between the purple and orange wires.
Thread Starter
|
Senior User
Joined: Nov 2012
Posts: 381
Likes: 0
The tools you will need are a DVOM, Digital Volt Ohm Meter. You can also use an analog one if you do not have a DVOM
If you are unsure how to use one there are lots of tutorials on You Tube.
The first test is to check the resistance on the primary winding on the coil.
You will disconnect the power leads to the coil and check the resistance between the terminals. They are marked + and - or Pos and Neg. If not the green wire should go to the neg.
You then do the same test between the center terminal on the coil (high tension lead/ coil spark plug wire) and the negative terminal.
The pick is the bit in the distributor that picks up the single in the distributor to trigger the ignition box to fire the coil..
There should be 3 wires coming from the distributor housing Purple Orange and Black The black is ground the other 2 are the signal wires. About 4" from the distributor there will be a plug this a good place to unplug the harness to test for the resistance between the purple and orange wires.
If you are unsure how to use one there are lots of tutorials on You Tube.
The first test is to check the resistance on the primary winding on the coil.
You will disconnect the power leads to the coil and check the resistance between the terminals. They are marked + and - or Pos and Neg. If not the green wire should go to the neg.
You then do the same test between the center terminal on the coil (high tension lead/ coil spark plug wire) and the negative terminal.
The pick is the bit in the distributor that picks up the single in the distributor to trigger the ignition box to fire the coil..
There should be 3 wires coming from the distributor housing Purple Orange and Black The black is ground the other 2 are the signal wires. About 4" from the distributor there will be a plug this a good place to unplug the harness to test for the resistance between the purple and orange wires.
Post Fiend
Joined: Feb 2008
Posts: 5,831
Likes: 121
From: St Albert, Alberta
That would indicate a toast coil. You had the DVOM on the correct range ? Just asking to be sure. Pos post to neg should just be ohms and neg to plug post should be 1K ohms. If you did then the coil is toast.
Thread Starter
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Senior User
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had it on 2m