95 Aurora idles rough and hard starting.

I have a 95 Aurora. After it sits overnight it can be hard starting, but it will start right up the rest of the day. Is this the fuel pressure regulator? I pulled the vacuum line and it has no fuel in it as someone stated it may if it was failing. Also it idles rough and you can feel it jerking as you drive. I put new plug wire and plugs in. I checked for spark on each cylinder by putting the impulse sender from my timing light on each wire. All cylinders were firing good. My next item to check is the injectors, is there anyway to check which may not be working. And what is the best product to use to try and clean them?

Thanks,
Bobg

If you have a definitive misfire under load and at idle I would attack this first. Was the miss there before the plugs and wires, if so you should try and isolate the suspect cylinder by killing one plug or injector at a time till you feel no change in engine rpm or roughness, this would be the one that is misfiring, if in fact that is the condition.

Maxwedge,

Yes, the misfire was there before I replaced the plugs and wires. The number 8 wire was broken at the coil so I had to replace them. How would you disable a cylinder at a time, I understand that you are not supposed to remove a wire while running. Is this true? I replaced the fuel filter and pcv today it seemed to idle better, we'll see tomorrow when I go to town. MPG is down to about 15 I was getting 25. I also checked all the fuses and disconnected the ground on the battery thinking that a reset of the computer might cure it.


What's the car in the picture? Is it yours?

Bobg

Maxwedge,

I found the problem. Even though I was getting spark on all the wires, check with my timing light. I tested the #3 and 8 coil with my ohm meter and there was nothing. So, I took one of the coils off of my Delta 88, which uses the same coil and that was the problem.

Thanks,
Bobg