Down shifting problems, I think
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Joined: Oct 2004
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Down shifting problems, I think
It has been a long time since I've logged onto the web site. Kids, wife, work all those things called life have kept me busy, but when I noticed a problem with my 97 F350 crew cab 4x4 I thought of you guys first. So here it is. The mods that have been done are 6637 intake, edge programmer, straight pipe with a 3" dp, shimmed the fuel preasure and a trans command. Problem is; when I'm driving and I slow down and the rpm's drop, but not slow enough to down shift, I will step back of the pedal to go, this is when it should down shift and it doesn't, the truck will drive but I don't have any power because the rpm's are low and I'm wanting to go. Its like the engine doesn't know that I'm pushing on the pedal. Now when the rpm's gets built up a little the truck comes alive and it is like nothing is wrong. So I put a trans command on it and the truck shifts great but the problem is still there. I can really notice it when I pull my horse trailer. I've taken it to my mechanic and he can't find any thing wrong and I've talked with a transmission shop and they said it sounds like my pedal is going bad. To be honest with you I don't know what to think any more. It is to the point my wife wants to get rid of the truck and get something newer. I love my truck and I'm not going down like that. Any help would be greatly appreciated.
Sean
Sean
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Joined: Aug 2006
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You Can test the TPS :
You need to put a voltmeter across the GY/W and the GY/R wires on the connector to the TPS. With the key on, watch the voltage across the range of the throttle to see if there is any flat spots. You should see no less than .37 volts at idle position and no more than 4.5 volts at full throttle. The the third wire, (BRN/W), is the ref. voltage and should be 5 volts all the time.
You need to put a voltmeter across the GY/W and the GY/R wires on the connector to the TPS. With the key on, watch the voltage across the range of the throttle to see if there is any flat spots. You should see no less than .37 volts at idle position and no more than 4.5 volts at full throttle. The the third wire, (BRN/W), is the ref. voltage and should be 5 volts all the time.
Thread Starter
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Junior User
Joined: Oct 2004
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I will give it a try and see what happens. It's really hard to explain but it is obvious when you drive the truck. I just need to take everyone for a ride. if this comes back fine, would you have any other ideas. Thanks
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Joined: Aug 2006
Posts: 10,764
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Make sure PCM to Trans wires are clean & tight , Maybe speed sensor on the rear axle (WAGS) ...
