Merry Christmas everyone!

 

This is a 1984 Turbo Wagon:

 

Have been encountering this problem for a bit now, and it really started acting up driving home from Christmas...

 

I'll be cruising along the highway, and then the engine starts to misfire. The tach will drop very erratically, then on bad misfires, it drops to 0 and comes back.

 

Also, at hot idle, it does the same thing, but usually ends up killing the car unless I keep the revs up to about 1500.

 

It really only shows this trouble when it has warmed up and been running for a bit.

 

What should I look at?

Since the tach is jumping around also, maybe the distributor shaft bushings? Hopefully GeneralDisorder will chime in, I think he had the same thing happen to his car. I'd think if the shaft has alot of play it would end up causing a misfire.

Pretty easy to check if thats it. The distributors are simple to pull, just check for shaft play.

+1 for the disty bushings. Sounds real simular to what the '86 BRAT did when it's disty died.

If its the disty, why does the problem only occur after its warmed up?

 

I can drive it when it is cold and she runs beautifully.

 

I'll have to pull it when it warms up a little bit outside. Anyone have an EA81T disty?

If its the disty, why does the problem only occur after its warmed up?

 

Possibly because the idle speed is lower.Could be bad ignition module

too.

 

I can drive it when it is cold and she runs beautifully.

 

I'll have to pull it when it warms up a little bit outside. Anyone have an EA81T disty?

 

No need to pull it,just remove the cap and try to wiggle the shaft.

Good EA-81T distys are hard to find.Having the original rebushed if

necessary is a plan.

 

If the tach didn`t drop to zero,it would seem like you have a

vaccuum leak.Check the disty vaccuum advance anyway.

Seeing as teh tach is droping all the way to zero, and that this occurs only when hot, I would suspect a dodgey ignition module first.

And just how does one go about pulling out the ignition module? Is there any test for it?

Its the black plastic thing with four terminals on it inside the distributor... You just have to take the cap, rotor and maybe a few more bits off to get at it.

 

There is no way to test it since your problem is only intermittant... therefore it is best to rule out everything else before trying a new one of these... (they aren't cheap!).

Check that the four wires going to the module are in good condition and that the connectors are firm. You may as well feel teh distributor shaft for play while you are in there. There will be some up/down play, but there shouldn't be very much side to side play at all.

Ross, sounds like a good plan for him. That way he can check both probable causes at one time. Good call

Shouldn't be shaft bushings - that would be tach jumping but no real change in engine speed. Your problem sounds possibly ignition related since the engine also tries to die. That's a real misfire, not just weird tach readings.

 

GD

Going to replace as much of the ignition system as I can afford.

 

Just *gulp* charged my credit card for an epoxy filled coil, spark plug wires, distributor cap, rotor, and spark plugs.

 

If that doesn't fix it, I'll scower the junk yards for an 83-86 turbo. The 85-86 EA82Ts should have the same ignition module. At least, that's what I've read in past threads.

 

I'm keeping the old coil in the back in case the new one fails like I constantly hear happening.

The 85-86 EA82Ts should have the same ignition module.

 

 

Yes, they do.