RPM Needle going crazy!!!

1994 NISSAN PATHFINDER
180,000 MILES
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TLOWDON
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On my 94 Pathfinder SE V6 Automatic yesterday I noticed while driving the RPM Needle jumped up to Redline then back down then it did it again and again it did it a bunch of times then it would jump halfway then go back down and do it a bunch of times then it would go dead for a while and then start going crazy again then it would work normal for a while then start jumping and going crazy again. It's been doing this the past few days. The only thing I did before it was happening was gave a VW a jump and had an Oil Change. So if you could please Help and give me some suggestions I'd REALLY appreciate it! Thanks in Advance.
Feb 18, 2012 at 5:25 AM
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RIVERMIKERAT
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You may have fried something in the ECU. Check the wiring to the distributor.
Feb 18, 2012 at 8:16 PM
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TLOWDON
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Ok thank you very much!
Feb 18, 2012 at 9:17 PM
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TLOWDON
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So if I did fry something what needs to be replaced? The ECU or the Distributor or Both and how will i be able to tell? I'm wondering if it has something to do when I jumped that car?
Feb 18, 2012 at 9:23 PM
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RIVERMIKERAT
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Most likely the ECU, unfortunately. Pay special attention to loose grounds and connections. There's also a control module under the right front seat. The grey wire there feeds the tach.
Feb 18, 2012 at 9:42 PM
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TLOWDON
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Ok thanks again!
Feb 18, 2012 at 11:27 PM
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RIVERMIKERAT
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My pleasure. Let us know what you find out and tell your friends about us!
Feb 19, 2012 at 1:47 AM
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TLOWDON
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Ok sounds good I hope I can figure it out and I always tell my friends how Professional you guys are!
Feb 19, 2012 at 2:40 AM
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RIVERMIKERAT
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The tach signal comes from a couple of sources. There's a crank position sensor in the distributor, and the negative, or tach side of the coil. Those feed into the control module I mentioned above, which generates the signal to the tach.
Feb 19, 2012 at 1:08 PM
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TLOWDON
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Ok I'm not to Mechanically inclined so I'll have to wait for a Buddy of mine to check it out thanks again!
Feb 19, 2012 at 6:29 PM
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RIVERMIKERAT
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My pleasure. Let us know what you find out.
Feb 19, 2012 at 7:12 PM
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TLOWDON
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Will do.
Feb 19, 2012 at 8:40 PM
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