delete

thanks

 

Are all your plugs firing?

 

hmm it sounds like it is, im sure it is, all the plugs are new, hmm, cap and rotor, hmm,. runs strong, but anything is possible, it is damned lloud with no exhaust so i might not be able to tell.,

ill have to check by pulling out each plug and comparing, they should all be light tan by now


what if they are all firing ? what then ?

thanks

 

No idea, the only time I've ever seen a tach bounce was because one hole wasn't firing.

 

ok, cool deal
ill try in about ten hours and see what i find

thanks

 

This is a long shot, but I have had success fixing an erratic tach once by moving the plug wires away from the distributor wiring (small wires).

phil

 

hey good point!

hmmm

thanks wll try that too

 

i rerouted and replaced some of the wires and still got a jumpy tach,

what else can it be, it seems accurate and all just wont sit still, needle flickery jumpy

i even put another hei cap on too, and another coil

thanks

 

How much is it jumping? Does it change with engine speed?

 

already tried, they are no where near them, plus i tried different wires

thanks

 

jumps the same all the time, the tach does register higher with engine rpm increase and keeps up with it, no delay or anythiung else bad, just needle is shaky all the time, and at idle it jumps with idle speed, consistently

just as fast as the engine is moving is how fast the needle jumps, all the time

it jumps around 400RPM maybe hair more

thanks

 

alright welp first i loosened up the glass hinge nuts and i was able to shove the glass forward soem so that at least now the pass side is flush then i tightened the nuts back up and then i went inside and loosened up the front ones in the roof metal and those bolts are already forward all the way as much as they are going to go, there is not much of a slot in the roof metal for the bolts to slide fore and aft in, not very elnogated at all, if any,

my driver side tail end of the hatch is way off still is way behind after the tail edge of the QP,

maybe they didnt tighten the tail metal panel of the hatch to the tail end of the glass correctly, it could be not centered right ont he tail of the glass, i dont know what else it could be sinc ei cant go forward any more at the hinges now and im still hanging off the end on driver side

also i noticed that the metal edge is coming off the glass pass side i think they did a real crap job of replacing the glass and some of the bolt studs on tail end of the hatch that clamp the metal tail panel over the glass are stripped and turn free so the glass isnt tightly clamped on a couple of the studs,.

i think the hatch is not really saveable, its apparently out of wack and not worth a damn, i think whoever replaced the glass screwed it up bad, it is missing driver side metal edge molding screws clip so i dont know how the edging is even staying on the glass and they had improper threads flat head screw shoved in the hole that holds the bottom end of the strut shock to the metal tail end hatch frame bracket

ill just have to pick up another hatch assembly later down the road when i come across another parts firebird thats got a rear hatch thats never been busted or anything,

i wish i would have saved one of one of the past firebirds i had, especially the damn 85 one, it was perfect shape and trans am across it and heat grid and all and i ended up busting it up so i could scrap it, i had no use for it i have a pic of it somewhere around here


dammit

this is how it always works..,

negatively...


thanks

 

any more ideas ?

thanks

 

I do believe this one is in the wrong thread as it has absolutely nothing to do with the jumpy tachometer.
Back on the subject of the jumpy tachometer, I had a similar problem with a jump tachometer in a 85 Z28. Had no clue what was causing it and neither did the three mechanics I took it too. One day I changed the brakes and bled them real good, For some reason the tachometer smoothed out and never gave me any more problems. The only explanation that I can come up with this is that prior to my problem with the jumpy tachometer. Another mechanic had pulled the vacuum check valve from the power booster while the engine was running and revved the engine several times. It is possible that he messed something up inside the power booster at that time and I corrected it when I bled the brakes good. Not saying that is what is wrong with yours but it fixed my problem.

 

...how bigs ur cam

 

is this a factory tach? i installed an aftermarket tach, and i have the same problem, it was because i had a loose wire where it tapped into the tach signal from the dist. so i would trace all the wries from the tach, make sure all the wires are in good shape, and the connections are all good

 

factory original 82 trans am 5.0L tach yes, and was just an old 1973 stock 350 engine

interesting on thje brake booster thing, wierd,,,,

thanks