4R70 Problem
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From: Northwest Indiana
4R70 Problem
i've had this problem for a while & can't seem to get rid of it. my car is worthless on snow so i really need to square this away, any and all help is greatly appreciated
in Park the engine will idle high, drop down than start idling iratically than start idling high again, sometimes it will level out, sometimes it keeps happening
when driving the transmission doesn't seem to want to shift(regardless of OD being on or off). at idle everything is fine, engine is at a good steady RPM. everything between idle and wide open throttle the RPM will go up but will not gain speed than the engine starts bogging down and the truck loses speed. at WOT the trans will shift kind of hard and the truck will get up and go after a while or if i let up on the throttle the truck seems like it shifts again(not sure up or down) and the bogging & loss of speed occurs again.
if the check engine light is on the problem goes away completely. it used to come on after a mile or so of driving and stay on. now it rarely comes on and when it does its only for a few seconds at most.
i've changed the mlps sensor to one that worked fine on my car(same transmission). i've also taken the truck in and had the line pressure (i believe, it has been a while) tested. they said the trans was fine, checked some stuff with the computer and said the only thing that showed up was codes from the engine(o2 sensor and some other things, the guy didnt tell me all of them) and they reset everything but the problem continued. Fluid seems fine. truck has stock 3.55 gears w/ 33" tires, speedometer was off so i recalibrated it with instructions from a post i found hoping it would cure it, but it didnt, almost seems like that made it worse. i'm thinking something with the engine(mainly a sensor) is causing it but have no clue what would do it.
in Park the engine will idle high, drop down than start idling iratically than start idling high again, sometimes it will level out, sometimes it keeps happening
when driving the transmission doesn't seem to want to shift(regardless of OD being on or off). at idle everything is fine, engine is at a good steady RPM. everything between idle and wide open throttle the RPM will go up but will not gain speed than the engine starts bogging down and the truck loses speed. at WOT the trans will shift kind of hard and the truck will get up and go after a while or if i let up on the throttle the truck seems like it shifts again(not sure up or down) and the bogging & loss of speed occurs again.
if the check engine light is on the problem goes away completely. it used to come on after a mile or so of driving and stay on. now it rarely comes on and when it does its only for a few seconds at most.
i've changed the mlps sensor to one that worked fine on my car(same transmission). i've also taken the truck in and had the line pressure (i believe, it has been a while) tested. they said the trans was fine, checked some stuff with the computer and said the only thing that showed up was codes from the engine(o2 sensor and some other things, the guy didnt tell me all of them) and they reset everything but the problem continued. Fluid seems fine. truck has stock 3.55 gears w/ 33" tires, speedometer was off so i recalibrated it with instructions from a post i found hoping it would cure it, but it didnt, almost seems like that made it worse. i'm thinking something with the engine(mainly a sensor) is causing it but have no clue what would do it.
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Joined: Nov 2002
Posts: 1,490
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From: Indianapolis, IN
glc is correct, you need to get the codes read. Autozone will indeed read them for free, but if you know someone who has an SCT device then you can get that done and it will include any transmission codes as well. A LOT of places can't read transmission codes because those are manufacturer specific.
I suspect the codes will include one for the throttle position sensor. And, maybe the idle air controller.
Darrin
I suspect the codes will include one for the throttle position sensor. And, maybe the idle air controller.
Darrin
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From: Northwest Indiana
yeah its ridiculous, i've got another one out here im gonna check out as well as a mechanic a buddy knows and the place i went to the first time, used to be a ford dealership, same ppl, same stuff just not owned by ford anymore
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From: Northwest Indiana
how exactly do i do it with the paperclip? havent had a chance to take her in but i did look around a bit and found a wire on the tps that was bare & corroding so i replaced the sensor, thought it eliminated the problem but it didnt, the check engine light just comes on more often like it used to
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From: Washington
how exactly do i do it with the paperclip? havent had a chance to take her in but i did look around a bit and found a wire on the tps that was bare & corroding so i replaced the sensor, thought it eliminated the problem but it didnt, the check engine light just comes on more often like it used to
im confused, you found a bare wire and replaced the sensor but did not address the wire?
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From: Northwest Indiana
(bare wire was attatched to the sensor,thus replaced with the sensor) but yeah i found the directions and did the test, not sure how well i did on recording it all correctly though haha. from what i understand(1st time ever trying this) on the KOEO i got 26-MAF/TOT, 63-TPS circuit and the memory 72-msg center/power interruption,66-MAF/TOT, 81-MAP sensor vaccuum. i would really like to record on video it and e-mail it to someone who is more experienced at this than me if anyone is willing i'd really appreciate it
Last edited by bigred5.0; Nov 30, 2009 at 10:29 PM.