valentiner
Member
- :
- Mazda MX-3 GS SE V6 1.8L
Removing plug wires at Cylinders 4 and 6 reveals no loss of performance; Engine starts barely and will stay lit; removing plug wire at 2 will stall engine. Spark strong when pulling 4 and 6. New plugs, some soot on 6 and nothing on 4; 4 plug is totally clean when pulled. I think I smell some unburned gas from tailpipe, but not sure.
Fuel pressure good (a few pounds more than on my K8 in fact), pump leak-down is gradual, faster than on my MX-3 GS, but don't see cause of problem. Tried swapping a fuel regulator from yard off MX-6, no difference, and pulling vacuum hose caused a difference.
Fuel filter and O2's x 4 are new (o2's are ebay cheapos, but, don't see how they would come into play before engine actually warms up if they suck); Ignition wires and plugs are new as well.
Compression good at all cylinders, ranging from 196 - 209 psi.
Resistance good at crank sensor, knock sensor, etc. Not sure if I checked the VAF for other than voltage present.
I shipped out fuel rails for service, pre-flow testing showed all good, from -6% to -11%(#4). Guy tonight suggested pulling rail and moving injectors around. Suppose I would have already done that if I hadn't had them serviced and it had occurred to me. Did back probe wires after rails re-installed for proper resistance and voltage. I have a 'stethescope' and pretty sure I hear clicking at injectors 4 and 6.
I assume timing belt is non-issue as compression test went as expected, and, if say it skipped a tooth on the front side bank sprocket, cylinder 2 would also be out of play, correct?
I know it's gotta be something dumb I just can't think of. Don't want to pull the rails to swap around injectors for another excersize in futility until I get some feedback. Thanks.
Fuel pressure good (a few pounds more than on my K8 in fact), pump leak-down is gradual, faster than on my MX-3 GS, but don't see cause of problem. Tried swapping a fuel regulator from yard off MX-6, no difference, and pulling vacuum hose caused a difference.
Fuel filter and O2's x 4 are new (o2's are ebay cheapos, but, don't see how they would come into play before engine actually warms up if they suck); Ignition wires and plugs are new as well.
Compression good at all cylinders, ranging from 196 - 209 psi.
Resistance good at crank sensor, knock sensor, etc. Not sure if I checked the VAF for other than voltage present.
I shipped out fuel rails for service, pre-flow testing showed all good, from -6% to -11%(#4). Guy tonight suggested pulling rail and moving injectors around. Suppose I would have already done that if I hadn't had them serviced and it had occurred to me. Did back probe wires after rails re-installed for proper resistance and voltage. I have a 'stethescope' and pretty sure I hear clicking at injectors 4 and 6.
I assume timing belt is non-issue as compression test went as expected, and, if say it skipped a tooth on the front side bank sprocket, cylinder 2 would also be out of play, correct?
I know it's gotta be something dumb I just can't think of. Don't want to pull the rails to swap around injectors for another excersize in futility until I get some feedback. Thanks.
