Chargin73

On the advice or Rotormotordriver, I found that I had a bad trailing ignitor, the reason my tach wasn't fucntioning. Well, bought two used ignitors, popped one on, fired it up. First thing I noticed, not nearly as much blue smoke on start up. That's good, must be acting as an afterburner. And the tach moved for the first time since being in my garage. HOWEVER, the tach movement is very erratic. At idle, around 800 rpm, it's very steady. But rev it up, and it stops at around 2000 (when it sounds like I'm up around 4000 rpm), then jumps around, bounces, and when I finally let off the gas, it ultimately settles back down to idle.

Any ideas? I checked and cleaned the connections to the ignitor, checked the basic ignition wires, everything seems tight. I'm hoping it's not a tach problem, I couldn't get the cluster out when I was trying 2 weeks ago!

You're thoughts...I'm almost there...of course, more questions to come. I love this place!!

Phil
69 AMX
73 Charger
85 GS
98 F150

Mr. ImportGuy

I to have a similar problem. Except my tach works except when it's cold out side. Then once the car warms up the tach works? Any ideas?

abeomid

I have seen this posted somewhere else. Check your gauge cluster. B/C apparently they use grease on the gauge shaft and that grease has be cleaned and applied again or the tach doesn't work right.

Chargin73

This is even stranger, just took it for a little spin, tach seem to work fine, reading I think correctly (in 3rd gear, at 45, showed 4000 rpm, which seemed about right.) But everytime I let off the gas, the tach would bounce around!! Huh?

But when I would pull away from a dead stop, it would climb about normal, even had it up to around 7000 rpm, seemed okay, but as soon as I let off the gas to shift, it would bounce again. I'm thinking the gauge itself may be getting ready to die...

You're thoughts...as always. Heck, I might as well leave you all in my will. Who want's my 85 GS 5 speed??

Chargin73

Abeomid,

I can try that, but it seems more like a signal issue than a physical issue. Now, how the heck do you get a gauge cluster out of an 85? I messed with it last week with no success.

BTW, you race Solo? I bought this car to race in PRO7, may have to pick your brain for some suspension mod ideas.

abeomid

Well before you take out the cluster, you should check to see if all the wires are intact on the trailing coil. It's the front coil on the driver side right beside the battery. I doubt that the coil is bad, but if you have any extra ones, you should give thema try.

Other than that for taking the gauge cluster out, you have to take the steering wheel off. Then the steering plastic surround. Then take the black trimming around the guage cluster. At this point you should see bunch of wiring. Just take the 4screws off the cluster. Now you have to get down on the floor and get your hand up behind the cluster and disconnect the speedo cable (it's a bitch, be ready to get some scratches). THen you pull the cluster out a little bit and disconnect the wires.

Make sure you have some beer handy and don't have any kids around you, b/c you're gonna be swearing alot

Chargin73

Okay, that doesn't make sense, I'm positive my trailing coil is the one closest to the firewall, under the alternator. I know because this was the ignitor that I swapped. Before, the tach didn't work, now after replacing it, it does. In addition, all my wires from the T coil to the Dizzy are marked with T on them and go to the T plugs. Guess I should have mentioned my car is a an '85 12A GS, seems the 84-85 car's igniters are different than earlier cars.

Thanks for the info on the cluster removal, sounds like an all day job. Mucho beer would be good...

abeomid

Ok you are confusing coils and ignitors. The coils are in front of the car close to the driver side headlight. They are two of them and they look like a cylinder.

Chargin73

right, and the igniters are the two little black boxes on either side of the distributor. The ignitor closest to the radiator is the leading, the one beneath the alternator is the trailing, this is the one I replaced.

Chargin73

I see what your saying, you said coil, I said igniter. Something about working graveyard shift and trying to fix a car. My error. Yes, I can check the trailing coil wiring. I guess I could also swap the coils and see if that makes a difference?

Thanks..