lrpman

Well the 84 is now driving just fine. The WIGGLE in the rear when you backed off was (2) missing washers on on each side of the shock where it mounted on the bottom.
Now I have an engine "SHUDDER" like a cylinder dropping out or just DEAD.
We tested the plugs and plug wire and also tested the spark strength (see if it was firing) It is isolated to #3 on the drivers side. Will pull and test the injection.
NEW plugs, wires, cap , rotor etc. So THINKING it is fuel problems. Will do a compression test BEFORE we blame the injection.

fraggle

Progress is always exciting! Stick with it!

gads I love that blue. I like my car, but the RED is so common!!

Imo000

Pull the injector plug on that cylinder and put a GM noid light to see if it's getting power.

lrpman

Thanks, 99% sure there is power TO the injector BUT the injector itself might be bad. I have (7) more spares so swap out is possible.
Never hurts to check that 1% since it is the most LOGICAL answer.

Landseer

I think you just pulled these for fuel line stubs? Easy enough to pull again to replace the injector. Might not even need new intake gasket. I would run a compression check, at least on that cylinder, and check the plug.

lrpman

Blue is mine a 1982, this one is the Grey, wifes.
It drove well except for the dead cylinder.

fraggle

Get the light, they all have power normally, I think... but I know the LH/EZK much better than the older cars.

Landseer

Well, the jetronic does. They all fire at once, but I think everybody here knows that.

lrpman

10-4 had the whole thing apart.
Plug will get checked after I run it in the morning back over to the shop.
The ORGINAL plug that cam out was NOT:
Oil fouled OR gas fouled, just looked like it was doing NOTHING. Other 7 wher a nice light grey.
We have a proximty tester for spark and it showed a good spark so I am thing fueling problem more and more.
Will run teh compression test also. Can also do the old, unplug the coil pull the injector and just spin it over to see if it putting any fuel out.

Mrmerlin

Here is a link to the firing order for a S4 and the layout of the cylinder numbering. this will put you on the same page as everyone else
https://rennlist.com/forums/928-foru...t=firing+order

lrpman

You CONFUSED me for a second. Side topic I guess.
Car in question is a 1984 Single ignition car.
WOW thought someone STOLE a distributor!!

Mrmerlin

It is isolated to #3 on the drivers side. Will pull and test the injection.
NEW plugs, wires, cap , rotor etc.

George, The reason I added the link was so you would see how the cylinders are numbered as the #3 in the driver side is actually #7.
The S4 wire layout doesnt apply in your case as you have a single distributor on the driver side cam housing
Only the 32Valve engines have the dual distributor caps, one on the front of each head.
And the early LH cars 84-85 Euro 16V have a twin dizzy on the driver side cam housing.
Glad you got the suspension figured out, I hope that you find the shudder iisue

lrpman

Thank you as I said I am LEARNING these cars:
Well problem was the MAF unit was bad, took the one from the parts car and smooth as silk. The plug had fire and the injection was fine.
NOW there is a Vibration under load. If this was my Mercedes I would go after the center bearing on the drive shaft support as the source.

Will get back to the 928 AFTER we load the race car for Daytona. Changed the oil, plugs and a little look over of the car. Still need to do a torque trip around the car.

Landseer

The 84 USA car has what is called an AFM with a springloaded door. Is that what you guys replaced?
It doesn't have a MAF per se.

tailpipe

vibration might be torque tube bearings lots of writeups on here to diagnos