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Topic: Tach jumping around under boost and accel (Read 1163 times) previous topic - next topic

Tach jumping around under boost and accel

Hey guys. Well there appears to be a gremlin in my car.. Anyone ever had the tach jump around while under acceleration and boost on a Turbo Coupe? Around 2500 rpm it starts to jump around between 2000 and 4000rpm. I replaced the TFI when I thought it was bad, and still doing it. Not throwing any codes either. Im stumped, if you have any ideas please throw them my way...

Thanks!

Oh yeah, when im at a stop, I notice the speedo bouncing up to 5mph too. Not sure if this is related or not..

Tach jumping around under boost and accel

Reply #1 –
I have a tach if you need one.$15.00 shipped.As far as diagnosing,I wish I could help.Someone will chime in.
'88 Sport--T-5,MGW shifter,Trick Flow R intake,Ed Curtis cam,Trick Flow heads,Scorpion rockers,75mm Accufab t-body,3G,mini starter,Taurus fan,BBK long tube headers,O/R H-Pipe, Flowamaster Super 44's, deep and deeper Cobra R wheels, Mass Air and 24's,8.8 with 3.73's,140 mph speedo,Mach 1 chin spoiler,SN-95 springs,CHE control arms,aluminum drive shaft and a lot more..

Tach jumping around under boost and accel

Reply #2 –
Can I use any instrument cluster voltage regulator for my tc? Think mine ped out all the sudden... If I bypass it, the guages start working.

Tach jumping around under boost and accel

Reply #3 –
Think im just going to replace my pip module... It could be bad, whats the big deal about dumping some more $$$ into it, man I already put like 1,000,000 or so into it.. Lol j/k

Tach jumping around under boost and accel

Reply #4 –
About anything in the ign system can cause such a problem(plugs, wires(esp), coil, dist cap).. Last one I I saw that acting similar, I wound up swapping the dist(after changing the TFI)... Apparently the pip had a problem...
 

Tach jumping around under boost and accel

Reply #5 –
Well I think I found it, the coil and the #1 plug wire were resting on the back of the alternator stator wire. There is a missing insulation boot on the back of the alternator and the wires were touching. I moved them and seems like all is well now. Thanks for the help guys!