Porsche Parts Catalog Porsche Accessories Catalog Porsche Technical Articles Porsche Tech Forums
 
  Search our site:    
View Recent Cars  |   Cart  | Project List | Order Status | Help    
 >  >
Coil Testing and Replacement
 
Bookmark and Share

Pelican Technical Article:

Coil Testing and Replacement

Steve Vernon

Time:

1 hour1 hr

Tab:

$85 to $220

Talent:

**

Tools:

10mm, 8mm wrench, multi-meter (for testing only)

Applicable Models:

Porsche 944 Turbo (1986-89)

Parts Required:

Coil

Hot Tip:

Disconnect battery when replacing

Performance Gain:

More power

Complementary Modification:

Check spark plugs

If you are having hard start troubles or the engine is not firing properly, the three places you should check are fuel, air and the spark. If you are not getting a spark to the plugs (please see our article on testing for spark) you may have a bad coil.

This article will describe for you a few simple procedures for testing the coil along with instructions for replacing it if it is bad.

To test the coil, make sure that you have a good battery first. Next, the coil should always have 12 volts when the ignition is in the ON position. With the ignition in the ON position, place your multi-meter on the black wire on the coil and the ground. If you are not getting 12 volts, then you have a problem with the ground or power to the coil. Next, remove a spark plug. Disconnect the coil wire from the distributor and ground the plug to the engine with a set of jumper cables. Do NOT touch the plug while running this test! Turn the ignition to the ON position. Jump the battery negative to the green wire on the coil. The plug should wire or spark for every time you touch the green wire. If it does not then the coil is probably bad.

You can also test the resistance on the coil by connecting your ohms meter to the black and green wire terminals and the resistance should be between 0.4 and 0.6 ohm. The resistance between the coil output terminal (where the plug goes) and the green terminal should be between 5000 and 7200 ohms.

The coil is located in the front right side of the engine compartment just to the right of the distributor and behind the headlight motor (red arrow).
Figure 1

The coil is located in the front right side of the engine compartment just to the right of the distributor and behind the headlight motor (red arrow).

If you have performed the tests and know that the coil is bad and are going to replace it, begin by disconnecting the ground to the battery (red arrow) and placing it so it cannot come in contact with the battery post while you are working.
Figure 2

If you have performed the tests and know that the coil is bad and are going to replace it, begin by disconnecting the ground to the battery (red arrow) and placing it so it cannot come in contact with the battery post while you are working.

The coil is located behind the headlight motor and should have a protective cover over it (red arrow).
Figure 3

The coil is located behind the headlight motor and should have a protective cover over it (red arrow).

If you have not performed the tests remove the cover and check the condition of the wires.
Figure 4

If you have not performed the tests remove the cover and check the condition of the wires. Look to make sure they are not dried out, cracked and are making good contact with the terminals.

To remove the coil, use an 8mm socket or wrench and loosen the bolt on the mounting bracket (red arrow).
Figure 5

To remove the coil, use an 8mm socket or wrench and loosen the bolt on the mounting bracket (red arrow).

Slide the coil up between the motor and reservoir, using care so as not to damage the wires.
Figure 6

Slide the coil up between the motor and reservoir, using care so as not to damage the wires.

Remove the plug to the distributor and check its condition.
Figure 7

Remove the plug to the distributor and check its condition. There should be no rips, tears or any scorch marks (red arrow).

The ground or green wire is connected with an 8mm nut (red arrow), while the power side or black wire is connected with a 10mm nut (yellow arrow).
Figure 8

The ground or green wire is connected with an 8mm nut (red arrow), while the power side or black wire is connected with a 10mm nut (yellow arrow). Remove the wires and connect to the new coil. Installation is the reverse of removal.


Bookmark and Share

  Search our site:    

View Cart & CheckOut | Project List | Order Status |  Help    

 

[Home] [Customer Service] [Shopping Cart] [Project/Wish List]
  [Privacy Statement]  [Contact Us] [About Us] [Shipping] [Careers]

Copyright © Pelican Parts Inc. -    DMCA Registered Agent Contact Page

Page last updated: Fri 12/9/2016 02:47:55 AM