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So new engine (jasper) is in and it has a misfire on 1,4,6,7. The new engine doesn't have the mds installed or the harness. Old tune was put back in as well. Would that cause a misfire and rough idle ? New plugs were used.
Thanks for the info. I have to look into all of thisAny codes other than the misfire? Such as MDS solenoid circuit codes?
So, I doubt it's a coincidence that the cylinders that are misfiring (1,4,6 and 7) are the cylinders with MDS lifters and the special cam lobe ramps for MDS.
Are you certain that your tuner has MDS disabled? And are you certain that the cam is non-MDS camshaft? And that the lifters are non-MDS?
There seems to be a competency and give-a-**** crisis in America these days, and I wouldn't be shocked to learn that Jasper got your order wrong.
The MDS lobes have a ramp that just slightly lifts the MDS lifters a few degrees earlier than the others, to take up the additional lifter lash.
non-MDS lifters riding a MDS cam lobe will partially open the valves way early, and cause misfires on 1,4,6 and 7. I've heard that exhaust gas can leak into the intake manifold and melt things too, but not sure how true.
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Ronald Reagan Trust but Verify
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