Lost OD in my 47re after vac pump replacement.

NickTF

NickTF

Single turbo turd.
Joined
Jun 4, 2007
Messages
5,887
I replaced my vacuum pump as well as went over valve train, injectors, and replaced my cam thrust plate. I lost OD since. Also, for the first time ever the wait to start light flashes non-stop. I removed my grid heaters a few years ago. Long long ago I put in a potentiometer to replace the TPS to control OD engagement. I think I need to start around the electrical connections in the vicinity of the vacuum pump as I may have pulled something out, hurt something, etc. Looking for any other things to check, brainstorming, etc. This is my 97 with a goerend 47re, i'm sure the issue is electrical as it showed up after the above described work.
 
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Also, for whatever it is worth the battery lost charge during the duration of the truck being down and I had to charge it to start. I don't think these trucks are sophisticated enough for any electrical OD engagement issues to arise from that but none the less a bit more info for anyone tossing out ideas.
 
zstroken said:
Do u have lockup? Tach?
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The trans does not lock up on its own (which it normally locks up on its own) but it will lock up when I throw the lock up switch. Tach works fine put the sensor in place with .050" clearance between it and balancer.
 
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sounds like a TPS issue. I had a POT in mine for a while and it worked great, then one day it just stopped working. tried switching it out with no change. Ended up putting a factory TPS back on and everything worked again. Mine also had the same symptoms, had a tach, wouldn't lock on its own but would with the switch, and no overdrive. sometimes it would shift to overdrive but would kick right back out and never try again too until the next key cycle. Mine is also a 47RH but sounds like your having the same issue I did.
 
sounds like a pcm issue to me, make sure you rehooked everything back up that you unhooked for the cam work.
 
stubz616 said:
sounds like a TPS issue. I had a POT in mine for a while and it worked great, then one day it just stopped working. tried switching it out with no change. Ended up putting a factory TPS back on and everything worked again. Mine also had the same symptoms, had a tach, wouldn't lock on its own but would with the switch, and no overdrive. sometimes it would shift to overdrive but would kick right back out and never try again too until the next key cycle. Mine is also a 47RH but sounds like your having the same issue I did.
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Thanks. Sounds like I need to check the wiring I bet anything something came loose given it was tugged on moved around etc.
 
NickTF said:
Thanks. Sounds like I need to check the wiring I bet anything something came loose given it was tugged on moved around etc.
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I also have heard of people using solid core wire for the POT wires instead of regular stranded copper wire and when they bent them they broke internally so you may have to ohm out each wire even if they look okay. Or if you have access to a scan tool just plug in to your truck and watch the TPS voltage as you turn your Potentiometer. that will tell you real quick if your wiring is okay and the computer is actually receiving the signal voltage.
 
The suspense was killing me so I went out to the garage during half time (49ers Seahawks)! As suspected one of the electrical connections was loose. Fixed it and OD/Lock Up works just as it used to!
 
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