Ok, before when my tach started jumping, someone said the plugs might cause too much resistance cause they needed to be replaced and then the spark would look for an "easier way out". Well, I changed my plugs and away it went.

Well, its back. I have new wires, plugs, distributor cap, rotor, and changed BOTH ignitors multiple times. Still, whenever I floor it in a semi bogging situation (like 35-40 in 4th), the tach will jump up and then come back down. Any other time its smooth and normal. Slow acceleration, heavy acceleration, cruising, etc. Nothing does it but flooring it at "low RPMs" for any given gear. It only jumps for a second or so, then comes back to working normally. Its just agravating. Also. at the same time, it feels that something is almost intermitant about the ignition, like its dying out when it jumps, and then coming back once the tach returns to normal, but Ive checked all I can think of.

So, if you guys could work with me and help me figure this out, I would greatly be appreciative. Thanks .

~T.J.

 

I have the SAME EXACT problem.

 

Remember Rob Golden's anaolgy of an engine working compared to a bicyclist? It takes more work when you're in the wrong gear to get going. The spark is not not jumping or the resisitance is so high you're getting the same effect as bad/old plugs. Time for DLIDFIS?

 

Have you tried replacing the fuesable link? When my tach was jumping that was the cause.

 

how much does it jump, i had a friend with one that just floated all over the place wildly, the tach was bad

 

Mine jumps mainly when boost starts to hit...at about 3000 it flys way over to 7000.

 

Yeah LOL, mine does that too, mainly in 1st, have no clue why? LOL. I think it has something to do with the pedal on the right, I forgot what its for tho? anyone know?

 

HAHAHA SMARTASS

 

Mine jumps different amounts. Sometimes only a few hundres RPMs, sometimes a couple thousand. Its just really random. I dont know what to do. Seriously, this bugs me, can you guys try and help?

~T.J.

 

you tried replacing the cluster for just ***** and giggles, I have seen 79's do this with bad points, but not a 1000 rpms or so, also have seen 80's with igniter boxes do the little idle at 750 and the rpm guage kicks ever so often to 1200 or so but that was bad parts, this sounds like a bad tach.

 

still what is that pedal on the right for? I know the one in the middle makes my head hit the windshield, and the one on the left makes the engine rev, but what is the one on the right for? I know i makes that little buzzer go off... LOL

 

you hooked up the buzzer on that thing? oh wait if you hooked up the stock stack it would buzz on its own

 

Sounds like too much work...lol

~T.J.

 

I think its just a weird electrical system in these cars.

I notice that my voltage guage (or whatever its called) will move, almost like the tach with the revs.

If I floor it, I produce more electrical power. Craziness.

 

The jumping tach may have something to do with our MSD Blaster 2 coils TJ, because I have never had this problem till after I installed them. Who knows, but it bugs the hell out of me too!

 

I had it before I installed them, thats part of the reason I bought them... Good idea though .

~T.J.

 

Just a friendly bump for the evening.

~T.J.

 

exact same thing happens to me, but mine goes away once its warmed up.

Could direct fire help at all?

 

and just a second question, the bullet connector that attaches to under the dizzy somewhere. That has something to do with the tach right?

 

I had the same problem when I first got mine. It turned out to be a bad battery. I tried with my friends battery first because I'm a cheap bastard. Never had that problem since.

 

I dont know what the hell is doing it. Mine still does it and I have lots of modified or upgraded pieces to both my ignition and electrical systems. Im really at a loss as to what causes this.

~T.J.

 

Do u have mechanical secondaries because that can cause the bog and sometimes jumps the tach. That is if you have mechanical secondaries and havent modified your accelerator pump.

 

I have the same problem on mine. It seems to be connected to the fuel gauge.
Sometimes my fuel gauge dies and when that happens, my tach starts bouncing all over the place.
Ive also noticed that happens on my bike as well (i know bikes and cars are different) but if i have something unplugged that shouldnt be unplugged, and the ignition is on, my tach goes nuts.
So perhapse you should check all your connections to your dash, (gas gauge, temp, oil, etc) and see if any of them are kinda shotty, or loose.

 

Sounds to me like you've got a regulator problem there Cody. Ya might want to check that out, cause I don't think that should be happening. Perhaps VERY slightly, but not much.

Brian

 

I just realized how freaking old this thread is. Are any of the problems people were talking about even relavent anymore? And why did it get resurrected?

Brian