I have an 84 GS and whenever i take off the tach doesn't keep up with the engine. So say if i take off hard when the engine reaches redline the tach will only be at about 3500 to 4000. What could cause this problem. I have searched and no one seems to have had this same problem.

 

See if you have consistent spark on your trailing plugs. Could be an ignitor (trailing) issue.

 

would the car still run strong if the trailing ingitor was going bad?

 

not sure but i have heard the trailing are mainly for emission uses, it even says that in my 79 haynes manual. i dont even think my trailing work at all so mostly its the ingnitor, if the tach was screwedup it problem not work at all. i would change ignitors first to see before you mess with the tach. i have heard that the its hooked to the trialing so you know when the ignitor goes out. good luck robert

 

which ignitor is the trailing one. is it the one closest to the fan or the other one.

 

its the one that is hard to get to because of the alternator. the leading is the one close to the fan it should be a j109, not sure if the other one is or not. hope this helps

 

As an aside (while you're looking into your trailing ignitor), these cars had a grease applied to the dial indicator on the tachometer and during cold weather conditions, the grease congeals back there, preventing the tach needle from moving until the interior gets warmed up. Once warm, the grease can flow and allows the needle to move as it should.

I've noticed this on my 84SE during winter months here (35-50 overnight lows), and it only does this during the first start of the morning. Once it heats up, the needle behaves correctly - and it NEVER does this in the summertime here.

My trailing ignition works fine because I pulled my plugs for a changeout a few weekends ago and they looked fine - plus, retiming with the light shows the trailing plugs firing just fine.

I don't know if there's a way to clean this grease out of there, but it'd mean pulling the gauge cluster, and I don't want to take the time for it now, especially with the temperatures coming up as we head into spring. HTH,

 

cool thanks man, i am gonna try to replace it and see if that works if not i will be back.

 

i tried changing the ignitor and its till does it. It never really gets cold around here and when it does its that much worse, but its doesn't rork right even when its warm. i really don't wanna have to install an huge aftermarket one. I hate the way those things look. I like a nice clean look.

 

bump

 

if your ignitor is fine I think your stock tach unit is fouled... remove the gauge cluster and replace the small circuit board/coil pack for the tach with one from a wrecker...

 

Ok i pulled the cluster to day and replaced the tach. It worked perfect. All the way to redline and no sticking. Then all of the sudden it just quit working. Put the other one back in and now it does not work either. I still have spark at the trailing. What could this be?

 

ok nevermind i figured it out

 

Well, what was it?

 

Well it was the tach to begain with and then it worked perfect and I reved it one hard time to see if it was gonna work right and it blew the trailing ignitor and the tach just stopped working. It still had spark but very weak spark. Replaced that and tach works perfect all the way to redline. Thanks for all you guys help. Also this would make for a great writeup, because I am sure I am not the only one with these problems.

 

bump