97 F150 4.6L Engine Troubles

AKBill

AKBill

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AKBill
So I jumped in the truck this morning headed for the airport for an early morning flight. Truck backfired and died. Smoke rolling out from under hood. Let the smoke clear and checked everything out. Tried to start and motor revs to 2200rpm and dies. Played with pedal and got to start but runs real rough will not idle.

Any Ideas, I'm guessing timing chain jumped a tooth. Engine has 136,000 miles.

Needless to say I did not get to go flying....:(
 
Hmmm, start simple and work from there. Hook it up to a scan tool and read the codes. Most auto stores will let you borrow one, and they aren't that expensive and real handy to own.
 
AKBill said:
So I jumped in the truck this morning headed for the airport for an early morning flight. Truck backfired and died. Smoke rolling out from under hood. Let the smoke clear and checked everything out. Tried to start and motor revs to 2200rpm and dies. Played with pedal and got to start but runs real rough will not idle.

Any Ideas, I'm guessing timing chain jumped a tooth. Engine has 136,000 miles.

Needless to say I did not get to go flying....:(
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Was that truck built by Yugo? I drove a 99 S-10 for 231,000 miles and never had an engine problem. The only reason I dumped it was fifteen years of Michigan road salt had eaten the body.
 
The 1997 6cy 4.2L was the Achilles Heel of the "new" Ford Design back then. Usually a well taken care of 4.6L should last a long time.

I agree with Paul to start with the Scan tool to help eliminate what it ain't.
 
Rough running and smoke makes me think either the vacuum line for the fuel pressure regulator could be a place to look. If it came loose, or broke (hard plastic line), or the diaphragm inside the regulator ruptured, then not only would you have excess fuel, but possibly unmetered air entering the engine. Also, the PCV system has a 'closer hose', which if ruptured, could cause rough running, idle issues, and/or rich condition.
 
The Ford 4.6L is about as solid as it gets. Check to see what codes it's throwing, look for any obvious disconnected vacuum lines or sensor connections (MAF/Coil Packs).


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Sounds like you lost a vacuum line somewhere. A big one.
 
SoonerAviator said:
The Ford 4.6L is about as solid as it gets. Check to see what codes it's throwing, look for any obvious disconnected vacuum lines or sensor connections (MAF/Coil Packs).
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Ran great Friday, Sunday no go. I'm on the same page, codes ... How do you check the coil pack?
 
AKBill said:
Ran great Friday, Sunday no go. I'm on the same page, codes ... How do you check the coil pack?
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4.6 should be COP, coil on plug. Read the codes, if any cylinder is misfiring, the codes will tell you. It would show as a P0301-P0308 depending on cylinder.
 
Check codes first, then check the wiring and connectors. Look for breaks and chafing in wires, especially where they contact something. Then check connectors, look for corrosion or loose connectors.

Also, this may sound stupid, but next time it happens check for coolant leaks. I had a pin hole in a radiator hose that would only leak badly when the car was very hot. It would squirt a steady stream of antifreeze directly into the alternator shorting it out. It's a long shot, but if you don't get any codes it's probably something like that or a wiring problem.

Oh, make sure your battery is good, if the voltage drops too low crazy things happen.
 
AKBill said:
Ran great Friday, Sunday no go. I'm on the same page, codes ... How do you check the coil pack?
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Just check to make sure the electrical connection on each of the coil packs (COPs in Ford parlance) is solid and the wires don't appear chaffed/broken. The COPs them selves can be ohm tested, but that's not necessary at this point. Any chance there was water in the fuel? I'd also wonder about a leaky/stuck injector that could be causing it. Getting the codes pulled will likely narrow down the offending cylinders.
 
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Dave Theisen said:
I don't think that engine has the COP's. I know my 98 4.6L doesn't.
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Yes it does. The 4.6L/5.4L all have the coil-on-plug system. There is a coil for every cylinder directly above the spark plug. They look like this only black instead of yellow, you can only see the upper half when installed on the engine, the stem is not visible because it goes down into the plug well.
140033.jpg
 
Weren't these engines notorious for spitting the spark plugs out of the heads? I would take all the coil packs off and make sure one of the spark plugs doesn't come with it.
 
Grum.Man said:
Weren't these engines notorious for spitting the spark plugs out of the heads? I would take all the coil packs off and make sure one of the spark plugs doesn't come with it.
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I believe that was just on the 2V-version of the 5.4L. It was a problem that was easily remedied though, once it was discovered.
 
Dave Theisen said:
Again, my 98' does not have the COP's. I know what they look like
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Is it in a truck/Suv? If you have a Mustang or Crown Vic, it may be the separate coil system with 2 banks of 4 wires. Either way, the theory is the same. Make sure the connections are all solid. I haven't seen any '98 F-series without the COP system, 4.6L or 5.4L, but that's just my experience. I'm sure build-date/manufacturing plant can control that design item.
 
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Grum.Man said:
Weren't these engines notorious for spitting the spark plugs out of the heads? I would take all the coil packs off and make sure one of the spark plugs doesn't come with it.
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I know some or all of these came with two piece plugs that liked to come apart, especially when trying to remove high mileage plugs during a tuneup and/or if anti-seize wasn't used. Definitely would cause smoke/vapor, rough running etc if one came apart.
 
Omalley1537 said:
I know some or all of these came with two piece plugs that liked to come apart, especially when trying to remove high mileage plugs during a tuneup and/or if anti-seize wasn't used. Definitely would cause smoke/vapor, rough running etc if one came apart.
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The 2-piece plug was a different issue which was related to the 3V 5.4L engines in the 04-08 F-series trucks/SUVs. The didn't come apart until someone tried to remove them for service. That spark plug P/N has been superseded with an updated design, and there is a TSB on the replacement procedure. They even had a special tool made (referred to as the Lisle tool) in order to extract broken spark plugs. Nickel anti-seize should be applied to the spark plug shield (not the threads) in order to prevent carbon-build up on the new plugs before installation. Problem shouldn't occur again if TSB is followed.
 
You can try to clean the MAF sensor with electrical contact cleaner, but it sounds like you already bought a new one. You're not using an oiled-air filter are you (K&N, etc.)


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AKBill said:
Correct Dave no COP's. I got a Mass Air Flow sensor code P0102. Input circuit voltage low. Going to run with the MAF sensor $75
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That would do it. I'd buy a new one, try rockauto for best price.

They do need to be cleaned from time to time, but if the truck went from running fine to running like trash overnight then you likely have a failed, not dirty MAF sensor.




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