Tracking down a misfire and low vacuum at idle. The misfire happnes roughly once a second but with no rhythm. All readings on scanmaster look normal except the BLM's jump from low 120's right to low 130's and then back again about once a second.(121..132..123..133..121..etc). Car runs well off of idle. Engine runs very quiet - no valve train noise - so I don't think there is anything mechanicaly wrong.
I have:
Replaced IAC and put in new plugs (R43's).
New Magnecor 10mm wires.
Checked and rechecked (and replaced a few) of the vacuum lines.
Sprayed card cleaner in the PCV hole with no change in idle speed.
EGR has been eliminated.
Checked cam sensor and crank sensor.
Recent timming chain and valve springs.
Checked ignition module/coilpack with Casper's tester.
Pulled off plug wires 1 at a time and checked for spark consistancy - looked good??
I guess next step is pull the intake and maybe heads.....
My question: is the misfire causing the low vacuum or the low vacuum causing the misfire????
I have:
Replaced IAC and put in new plugs (R43's).
New Magnecor 10mm wires.
Checked and rechecked (and replaced a few) of the vacuum lines.
Sprayed card cleaner in the PCV hole with no change in idle speed.
EGR has been eliminated.
Checked cam sensor and crank sensor.
Recent timming chain and valve springs.
Checked ignition module/coilpack with Casper's tester.
Pulled off plug wires 1 at a time and checked for spark consistancy - looked good??
I guess next step is pull the intake and maybe heads.....
My question: is the misfire causing the low vacuum or the low vacuum causing the misfire????
