1997 Runs Rough
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1997 Runs Rough
I have a 1997 with 4.6 and about 175000 miles. I say about 175 because the odometer quit about 6 years ago on 147.
Issue 1: Sometimes when you turn the key the starter will engage and sometimes it will not. I usually have to turn to start then off 4-5 times before the starter will engage. Sometimes locks and other things click right before the starter engages like the battery was disconnected and then was reconnected.
Issue 2: If it sits for 3-4 days when it initially starts up it runs really rough for 3-4 minutes then smooths out and runs fine. The furthest I drive it is about 30 minutes but it runs fine the whole time.
Issue 3: After sitting it starts and runs fine for that 30 minutes or so but if I shut it down it will not restart unless I let it sit for 5-6 hours.
Any help would be greatly appreciated.
Issue 1: Sometimes when you turn the key the starter will engage and sometimes it will not. I usually have to turn to start then off 4-5 times before the starter will engage. Sometimes locks and other things click right before the starter engages like the battery was disconnected and then was reconnected.
Issue 2: If it sits for 3-4 days when it initially starts up it runs really rough for 3-4 minutes then smooths out and runs fine. The furthest I drive it is about 30 minutes but it runs fine the whole time.
Issue 3: After sitting it starts and runs fine for that 30 minutes or so but if I shut it down it will not restart unless I let it sit for 5-6 hours.
Any help would be greatly appreciated.
Fleet Mechanic
Joined: Jul 2010
Posts: 1,354
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From: Winnipeg
https://www.ford-trucks.com/forums/1...rks-stops.html
1, How old is the battery? Have you had it load tested? Are your battery cables in good shape, cleaned and tight to the battery post? When you try to start the engine; have you checked for a neutral safety issue by holding your foot on the brake, turn the key to start and hold it there, with no cranking heard, move the shifter slowly from park through to neutral to see if the vehicle starts. That may indicate a bad digital transmission range sensor.
How old is the starter? Have you gone under the truck to check the condition of the cable connections at the starter. I think some aftermarket starters had a quick push on connector for the pull-in wire. These can easily corrode and cause start issues.
Ignition switch may also be worn but I'd start with the previous checks.
1, How old is the battery? Have you had it load tested? Are your battery cables in good shape, cleaned and tight to the battery post? When you try to start the engine; have you checked for a neutral safety issue by holding your foot on the brake, turn the key to start and hold it there, with no cranking heard, move the shifter slowly from park through to neutral to see if the vehicle starts. That may indicate a bad digital transmission range sensor.
How old is the starter? Have you gone under the truck to check the condition of the cable connections at the starter. I think some aftermarket starters had a quick push on connector for the pull-in wire. These can easily corrode and cause start issues.
Ignition switch may also be worn but I'd start with the previous checks.
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https://www.ford-trucks.com/forums/1...rks-stops.html
1, How old is the battery? Have you had it load tested? Are your battery cables in good shape, cleaned and tight to the battery post? When you try to start the engine; have you checked for a neutral safety issue by holding your foot on the brake, turn the key to start and hold it there, with no cranking heard, move the shifter slowly from park through to neutral to see if the vehicle starts. That may indicate a bad digital transmission range sensor.
How old is the starter? Have you gone under the truck to check the condition of the cable connections at the starter. I think some aftermarket starters had a quick push on connector for the pull-in wire. These can easily corrode and cause start issues.
Ignition switch may also be worn but I'd start with the previous checks.
1, How old is the battery? Have you had it load tested? Are your battery cables in good shape, cleaned and tight to the battery post? When you try to start the engine; have you checked for a neutral safety issue by holding your foot on the brake, turn the key to start and hold it there, with no cranking heard, move the shifter slowly from park through to neutral to see if the vehicle starts. That may indicate a bad digital transmission range sensor.
How old is the starter? Have you gone under the truck to check the condition of the cable connections at the starter. I think some aftermarket starters had a quick push on connector for the pull-in wire. These can easily corrode and cause start issues.
Ignition switch may also be worn but I'd start with the previous checks.
Lead Driver
Joined: Sep 2006
Posts: 7,907
Likes: 143
From your description, there may be two different issues.
1. The ignition switch may not be closing all the way due to being faulty if the rod that operates it from the key area has been stretched or worn.
2. The cold start issue may be a faulty cylinder head temperature sensor, intake air temp sensor, or the IAC (when cold).
These items are the only way the computer has to know of a cold start setup to run richer, set the IAC open for more air, and adjust the ignition timing.
As the ox sensors heat up, they begin to send control signals to the computer , then goes into closed loop position and lowers idle.
1. The ignition switch may not be closing all the way due to being faulty if the rod that operates it from the key area has been stretched or worn.
2. The cold start issue may be a faulty cylinder head temperature sensor, intake air temp sensor, or the IAC (when cold).
These items are the only way the computer has to know of a cold start setup to run richer, set the IAC open for more air, and adjust the ignition timing.
As the ox sensors heat up, they begin to send control signals to the computer , then goes into closed loop position and lowers idle.
Tuned
Joined: Feb 2009
Posts: 295
Likes: 9
From: New Lisbon NJ USA
Rough running upon startup can also be caused by a number of different things other than computer related
Coolant leak down into cylinders
Fuel injector leak down into cylinders
bad plugs
Bad Coils
What does the exhaust look like when you first start and it is running rough...black smoke~ excess fuel, white smoke/steam ~ water in cylinder ...what does the exhaust smell like.
What is your oil consumption
Valve seals could be leaking oil down into cylinders
Coolant leak down into cylinders
Fuel injector leak down into cylinders
bad plugs
Bad Coils
What does the exhaust look like when you first start and it is running rough...black smoke~ excess fuel, white smoke/steam ~ water in cylinder ...what does the exhaust smell like.
What is your oil consumption
Valve seals could be leaking oil down into cylinders
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Also, if you are turning the key that many times, the ECM locks and unlocks the doors in prep for programming key fobs. My oil pressure gauge acts funny on my 97, so I rocked the key and the locks cycled themselves. I replaced the dash in mine as well because my trip and odometer wasn’t working.
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Thank you for the replies. I will look into those suggestions. I can really live with issues 1 and 2 it is the third issue that makes the truck basically unusable.
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Fleet Mechanic
Joined: Jul 2010
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From: Winnipeg
Check for cracked vacuum hoses and pcv lines. Check the air intake tube connections from MAF sensor to throttle body. I'm also wondering if you have an intake manifold gasket issue.
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Check engine light is not on but I did hook up the ODB2 reader and Torque Lite did not show any stored faults.
Mountain Pass
Joined: Apr 2019
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Not saying this is your problem but I fought some of these problems in a past truck and replaced a lot of parts to ID a crappy reman starter as the problem. my experience chronicled at a different forum below.
https://www.f150online.com/forums/el...lp-needed.html
https://www.f150online.com/forums/el...lp-needed.html
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