Misfire log, what to check next? MSPNP N/A car
#1
Misfire log, what to check next? MSPNP N/A car
Car details.
92 Miata with 94 1.8(2001 bottom end)
Intake
Stock header
exhaust
MSPNP 90-93 no maf
Misfire occurs most often between 5800-6200. Sometimes it'll get a blip at 5k. Very noticeable on the dyno graph. Changed coil, igniter, wires also tried adding grounds etc. Plugs are gaped correctly. Timing is staying true while watching with a timing light, however the light flickers differently during the misfire. Ive updated the firmware of the MSPNP, I have another PNP in another car im going to try also.
Log is from a 4th gear pull on the dyno
Thanks in advance!
92 Miata with 94 1.8(2001 bottom end)
Intake
Stock header
exhaust
MSPNP 90-93 no maf
Misfire occurs most often between 5800-6200. Sometimes it'll get a blip at 5k. Very noticeable on the dyno graph. Changed coil, igniter, wires also tried adding grounds etc. Plugs are gaped correctly. Timing is staying true while watching with a timing light, however the light flickers differently during the misfire. Ive updated the firmware of the MSPNP, I have another PNP in another car im going to try also.
Log is from a 4th gear pull on the dyno
Thanks in advance!
#9
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Please keep in mind that I have 0 experience running MS - I still am missing important engine parts.
But it looks like your MAP is all over the place. Almost 20% deviation. That may trigger enrichment and leaning out pretty much randomly. Also your O2 sensor doesn't seem to work...
Of course I may be wrong!
But it looks like your MAP is all over the place. Almost 20% deviation. That may trigger enrichment and leaning out pretty much randomly. Also your O2 sensor doesn't seem to work...
Of course I may be wrong!
#10
We're not using an O2 sensor, as for the map we pretty much put the car on the dyno to do WOT tuning first. Haven't spent much time on anything else.
I loaded a map from another 1.6(my old setup) car and added some fuel and it did the same thing in the same spot.
Being we've swapped near everything I imagine it's a harness/resonance issue.
One thing that seems odd to be is not only is the map flickering up and down, but so is the injector duty cycle during a pull.
I loaded a map from another 1.6(my old setup) car and added some fuel and it did the same thing in the same spot.
Being we've swapped near everything I imagine it's a harness/resonance issue.
One thing that seems odd to be is not only is the map flickering up and down, but so is the injector duty cycle during a pull.
#13
The CAS sensor was extended but it appears to be with non shielded wire, never been an issue in other swaps I've done but defiantly worth a shot.
The car doesn't run a crank sensor.
I'm going to try a few other simple things when I can get the car back on the dyno. I'll report back if we find it.
The car doesn't run a crank sensor.
I'm going to try a few other simple things when I can get the car back on the dyno. I'll report back if we find it.
#16
Bell,
Which wires?
Matt,
I appreciate your reply, something so simple for us to not to think of trying. I hope to have the car back on the dyno tomorrow afternoon. I do believe its routed on one of the nipples under the 94-97 manifold, I'll have to check with the car owner as he installed the MS.
Which wires?
Matt,
I appreciate your reply, something so simple for us to not to think of trying. I hope to have the car back on the dyno tomorrow afternoon. I do believe its routed on one of the nipples under the 94-97 manifold, I'll have to check with the car owner as he installed the MS.