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Discussion Starter · #1 · (Edited by Moderator)
My 97 4.6 with the 4R70W is acting weird again. It feels like I'm about to stall my automatic car when I take off semi-quick from a stop sometimes. It started after i drove to work in the rain, I started the car and it was idling weird and jerked pulling out of my parking spot so I stopped and checked to see if I had any new codes. I had a p0174 so i cleaned the MAF. That seemed to help for a few but this morning i am driving to work and stopped at a light on a decently sloped hill and when i gave it gas it felt like i stalled my dads prelude in a Walmart parking lot, just kinda jumps n jerks but doesn't fully die. Obviously that doesn't feel good so i let off the gas, usually i can just ease back on the gas and it drives fine but today it jumped and jerked AGAIN, 2 times in a row at the same light so now I am real concerned. Does anyone know what can be the issue? I'm thinking its possibly my fuel system (fuel pump isn't old at all but my small brain chose to not change the in-line fuel filter at the time) or vacuum leaks but i have no idea. I'm going to change the fuel filter today because it seems easy and I'm stumped but let me know what yall think can be the problem. Please

Also have a p0340 I cant seem to get rid of. Ive changed the sensor like twice so something else is up I cannot seem to find what it could be. Possibly the connector because its all folded where its located but that looks alright as well. Is there any other possibly common fixes to this code?
 

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I had a V6 Explorer that would buck n shake like crazy at times, it turned out to be the crank position sensor.
Were the new sensors you used Motorcraft? Or at least name brand? There's been plenty of discussion about cheaper sensors being bad out of the box or dying quickly. I'm not familiar with this sensor on our cars, they are hall effect sensors though, meaning they measure a change in magnetic field based on how close metal is.

I'd visually inspect the wiring and see if you can measure the resistance from the connector to the ECU to make sure you don't have a broken wire.
 

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That sounds like either a fuel problem or an ignition problem. How new are the plugs/wires? Still using the stock fuel pump?
 

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Fuel pressure drops will act like that; when the 97's was dying. it would drop out at WOT. But the bigger problem was the not starting part.
 

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Sorry, I accidentally deleted your replies while trying to merge your posts on my iPad. Damn technology!
 
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Discussion Starter · #6 ·
That sounds like either a fuel problem or an ignition problem. How new are the plugs/wires? Still using the stock fuel pump?
Spark Plugs/Wires are less than 30kish miles so not extremely old and I have a Walbro 255 that is less than 15k miles old, I just have neglected the fuel filter which im about to go home and do.
Fuel pressure drops will act like that; when the 97's was dying. it would drop out at WOT. But the bigger problem was the not starting part.
You arent saying you think my bird is dying are you?:cry: My car seems to be good at WOT and starts fine up fine ever since I switched the PCM.
 

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Discussion Starter · #7 ·
I had a V6 Explorer that would buck n shake like crazy at times, it turned out to be the crank position sensor.
Were the new sensors you used Motorcraft? Or at least name brand? There's been plenty of discussion about cheaper sensors being bad out of the box or dying quickly. I'm not familiar with this sensor on our cars, they are hall effect sensors though, meaning they measure a change in magnetic field based on how close metal is.

I'd visually inspect the wiring and see if you can measure the resistance from the connector to the ECU to make sure you don't have a broken wire.
Im not using Motorcraft sensors just "Standard" from Oriellys. ill definitely check the resistance on that and the crank sensor.
 

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Discussion Starter · #8 ·
Well I changed the fuel filter and that helped ZERO. I noticed the jerking/jumping happens when I come to a complete stop and stay stopped for a few seconds. The car comes to a stop then my RPMs drop a lil (from like 900 to 700ish) then I accelerate and it jumps. Almost feels like its in 1st then immediately starts to go into 2nd but very violently. After it jumps/jerks it has very little power and is in low RPMs, thats what is making me think its just going to a higher gear too soon. Does this info maybe sound like something familiar to anyone?
 

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What engine and transmission is this?
 

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Sounds like it needs some maintenance. Maybe vacuum hoses leaking, worn spark plugs, or spark plug wires, or coil pack, or PCM. Possibly a bad idle control valve.

Al
 

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Discussion Starter · #12 ·
Sounds like it needs some maintenance. Maybe vacuum hoses leaking, worn spark plugs, or spark plug wires, or coil pack, or PCM. Possibly a bad idle control valve.

Al
I just ordered an Idle Control Valve, TPS sensor, connector, and I bought all the vacuum hose I think I need yesterday. $400 for all Motorcraft at Oreillys!!!:oops:My employee discount brings it down to $135...thats cool with me:LOL:. I appreciate your input a lot.
 

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I just ordered an Idle Control Valve, TPS sensor, connector, and I bought all the vacuum hose I think I need yesterday. $400 for all Motorcraft at Oreillys!!!:oops:My employee discount brings it down to $135...thats cool with me:LOL:. I appreciate your input a lot.
I had a similar problem with my 95 4.6. The conditions varied, but from a standing stop it'd feel like it was stalling under heavy throttle. Let off for a second to reset it and off you went. It turned out to be the Mass Air Flow Sensor.
 
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