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Discussion Starter · #1 ·
That's what the tachometer says anyway.In third gear I floor it and the tach jumps up to 7000rpm and stays there as the car accelerates. It will accelerate up to 150 doing it this way. Any thoughts at all are welcome.What other information would be helpful from me.
 

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Is the actual engine rpm jumping to 7000 at the same time?? You can hear it happening??

My first thought is the tach has a problem or is dealing with electrical interference and giving you a wildly inaccurate reading.

What tachometer?? Stock or aftermarket and brand??
What engine, and what vehicle.

If 3rd gear is actually slipping like that, transmission life will be measured in minutes, not even hours.
 

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Discussion Starter · #3 ·
Is the actual engine rpm jumping to 7000 at the same time?? You can hear it happening??

My first thought is the tach has a problem or is dealing with electrical interference and giving you a wildly inaccurate reading.

What tachometer?? Stock or aftermarket and brand??
What engine, and what vehicle.

If 3rd gear is actually slipping like that, transmission life will be measured in minutes, not even hours.
Good questions , thinking about it I have been So transfixed with the tach that maybe the car isn't revving as the tack indicates. It is a sun-pro aftermarket but the tack in the car can be hooked up to verify rpm. So I can try that . Its a 87 Camaro with a 355 built block and built tran. I have a breakdown of the build around here someplace if that would help. Could it be to low of pressure from TV adjustment or a lock up not locking. It has a 3200 stall converter.
 

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I've seen so many tachs go bad and cause ignition problems it's not even funny. Seems like I hear about it once a week from somewhere
First thing is too unplug it, second is verify the actual RPM, third is to verify what gear its in.
 

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Discussion Starter · #5 ·
I've seen so many tachs go bad and cause ignition problems it's not even funny. Seems like I hear about it once a week from somewhere
First thing is too unplug it, second is verify the actual RPM, third is to verify what gear its in.
Will unplug it and hook up the one that is in the care already. It's a 700R4 which wont shift into 4th under power,it is third gear .That and My ability to count insures it is in 3rd.
 

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If the trans was actually slipping like that, you would never make it to 150 mph, not even the first time. The heat generated would burn out 3rd gear in one pass.

I think it has to be the tach.

If you've got an aftermarket ignition box, some tach's will not play nice with some boxes. I know, at least in the past prior to 10 years ago, many of the Sun Tune/Sun Pro/Sun Super tachs wouldn't work with an MSD ignition box without having to use a tach adapter box in between.
A lot of the factory tach's in the 80's and 90's cars is the same way.

If you can actually hear the engine jump rpm instantly to 7000 and hold there, while the car accelerates and in an handful of seconds it "catches up" to the engine rpm then I would start to suspect the torque converter can't handle the power, not built good enough and you are blowing through it.(or it is broken)
 

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Discussion Starter · #7 ·
Thanks for the response , This is the converter. SRL series 9.5" billet 3200 lockup converter, I will be hooking up the another tach to see whats going on I'll let you know. Thanks --I'm in Minnesota and I have to put the car away before snow, There is no access during the winter , so my season is coming to a end. I'd like to get this settled before winter If I can.
 

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Discussion Starter · #8 ·
Well this is where I'm at , disconnected My aftermarket tack connected the one that is in the car It worked normally , Ran a flash stall test it showed about 3800 flash stall, ran just a stall test and didn't give me much information. Seemed to force my tires right from beginning acceleration. Its a SRL series 9.5” billet 3200 lockup converter. I reconnected the aftermarket tach and that's working fine again also. So I Don't really know what happened but I'm happy with it back to where it is,
 

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Discussion Starter · #9 ·
Thanks everyone , I didn't want that sitting up in the air all winter while it was in storage. SO it's back to normal and for right now that's fine. Its been a great year, used it almost daily.put on a couple thousand miles . It needs a lot of work to keep it running sweet but I enjoyed it. So it was a good year.
 
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