940 Turbo Firing Order
 

Did basic tune up on my 1995 940 turbo. New plugs, wires, cap and rotor. During the process, my step son took the wires off the wire spacer, so I lost my firing order. Found the firing order in the owners manual. Found Chilton reference that said cylinder 1 was the rear cylinder (closest to the firewall), with clockwise rotation. The rotor is mounted (apparently) on the end of the camshaft. So is clockwise facing it? I have everything hooked back up, car starts, but stumbles, idles rough, very little pulling power. I have removed and replaced the wires to make sure they are tight. Then I get on this forum, and find a 5 cylinder diagram where the numbers aren't in order on the cap so I am stumped. Any help?

You do have the rear cap setup correctly?
If so standing in the front of the car looking at the cap from Left to right it is 4,3,1,2

Here is a photo to help:

http://i426.photobucket.com/albums/p...100_8020-1.jpg

The firing order is 1-3-4-2. TIPSP is correct for the placement of spark plug wires. A clearer picture and explanation are available at www.stepbystepvolvo.com. Click on "Noises, Poor Performance, Easy Fixes, and Tune Up."

You guys rock. When I finally slowed down and looked and saw that it read
4 3 1 2 on the distributor cap, it worked great.

Since we are here, can I ask one more question? I have had a problem over the last 18 months or so. When I have the air conditioning on, blowing from the face vents, any time there is a load on the motor, the air stops coming from the vents. I have talked to a couple of Volvo people (one Volvo dealer, one independent Volvo shop and they both want to replace the bellows for the air box. Both have said it requires removing the dash, and putting it back. The dealer mechanic (and it seems to be substantiated here) said I would probably break 30-40% of the plastic pieces if I tried it, since it is 14 years old (and has not been garage kept for the last 7). Could the need for a tuneup have been causing vacuum shortages, making it seem as if the bellows were leaking? (for that point, when I pulled the plugs the gap was at least .055, no where close to the .028-.032 that was recommended. The distributor cap and rotor button were about the worst I have ever seen). When I test drove it this afternoon, it seemed like it behaved a little better, that is why I ask. If that has nothing to do with it, would an auxiliary vacuum canister help? I HATE the thoughts if paying $85 an hour for some mechanic to pull the dash, to fix a $45 part. Or, in your experience, is it something else? I know, that was multiple questions, please forgive me.

There is also a check valve under the hood that goes bad that controls the vacuum system.