Newbie - Engine missing
 

First post. I've been lurking here since I purchased my '82 SC ROW last November. It has run like a top as a daily driver. However, last weekend I decided to change out the ragged heater hoses (all three) to make the engine compartment look a bit nicer.

Upon starting it up the next morning it sounded as though it was running on 4 of the 6 cylinders. I must have somehow upset the delicate balance of Teutonic harmony wrestling with the hoses.

Thinking I had knocked a spark plug wire fitting loose, I checked all and found one that snapped back into position. But it did not remedy the miss. The miss is at idle and remains constant even if revved up.

Below is the obligatory photo.

Anyone have any ideas?

Thanks,
Terryhttp://forums.pelicanparts.com/uploa...1223610766.jpg

when the plug wire was off, it may have fouled that plug. I'd replace it.

Then, check carefully for vacumn leaks, u could have knocked a hose loose....G'luck

Easy test follows, but you'll need a pair of insulated pliers.

With engine OFF, pre-loosen the plug wires in the distributor cap, but leave them sort of in their respective terminals.

Engine ON, adjust idle to 1200 rpm or so.

With the insulated plier, temporarily short out each plug wire (pull wire from the cap) in turn and notice/observe the drop in rpm. The rpm should drop on each cylinder slightly when the spark is removed. The cylinder that doesn't change rpm is the weak cylinder, the one not contributing. That's the cylinder to inspect.

Engine OFF. Remove plug wire and check resistance. Should be around 4000 ohms. Remove the spark plug and inspect and/or replace. It could just be fouled with oil or excess fuel. Clean or replace with a known good plug, then retest.

If cylinder is still not contributing, you may have to perform a compression test to determine if the basic foundation of the engine is sound and not something relatively minor like the above.

Hope this helps,
Sherwood

PS: BTW, the above test is called a "Cylinder Drop Test" or Cylinder Balance Test".

When I saw the thread title "Engine Missing", my first thought was to suggest looking in the trunk in the rear, but then...... Oh never mind.SmileWavy

Happy Porsching!!

Best

Tom:)

911pcars:
Thanks for the test, I'll try it over the weekend. The plug wires are the steel mesh shielded kind and look a bit old. In fact, some of the covers for the spark plug holes are torn so it may be time for a new set of wires.

mossguy:
I thought the same thing after I posted. I tried to edit it to "Engine miss", but the edit program won't allow the title to be changed.

Newbie - Engine missing

The engine is in the back, not the front.

LOL

+1 (Since it said "Newbie - engine missing)!!!

Well, I looked closer at the spark plug wires and found they were cracked and worn so, I decided to follow Wayne's advice in the 101 Projects book and replace the wires, spark plugs, rotor and distributor cap.
Unfortunately, the rotor does not look like the one Pelican Parts provided and will not slip off when pulled upward. The cap looks the same, but the rotor is different.
I'm posting a photo of the old rotor and the new one provided by PP.
Should I give it a big tug to remove or is there some type of hidden spring or lever to pull?
Thanks in advance.http://forums.pelicanparts.com/uploa...1225343750.jpg

You have a rev limiting rotor installed and the replacement is a non-rev limiting one. That is why they look different.

To remove the rotor, give it a good tug, it should pull off, no secret fasteners.

Compare the two rotors, what is important is the length from the center of the rotor to the contact tip. They should be the same.

Push on the new rotor.

BTW, what does the inside of your cap look like? I know that mine will get grimy inside and a quick wipe to remove the grime will seem to help the idle smooth out a bit. Do the contacts inside the cap look ok or are they burned?

Me too :)

My thought as well!:p

Harry D:
Thanks for the info. Very helpful.

The inside of the old cap is a bit dirty, but it is being replaced just in case there are cracks or worn connections.