So I completed the engine swap in our 99 Suburban. I now have a miss. Using Torque, it shows up ONLY on cylinders 1 through 4. It's usually cylinders four and one. I've replaced the cap, rotor, wires, shuffled the spark plugs around and adjusted the valves twice. It only happens when letting of the throttle like after an acceleration or cresting a hill on the interstate. Never during heavy load. I've managed to get it in the 2-3 shift, but not consistently and it required a manual 2-3 shift during light load. I've run it in 3rd on the interstate at 65-70 mph and it didn't miss.
If I unplug the MAF, it goes away. Cool right? I swapped the MAF from my crew cab and nothing. The crew cab runs fine, Suburban still misses. Not cool. I've been racking my brains over this.
My only out of the ordinary thing, is the #2 plug was a little sooty upon removal the first time. MAP and TPS both appear good via the torque app but I've not had a meter on them yet.
I did swap in a Delphi mpi conversion during the engine install, I'm beginning to eye it as the cause.
If I unplug the MAF, it goes away. Cool right? I swapped the MAF from my crew cab and nothing. The crew cab runs fine, Suburban still misses. Not cool. I've been racking my brains over this.
My only out of the ordinary thing, is the #2 plug was a little sooty upon removal the first time. MAP and TPS both appear good via the torque app but I've not had a meter on them yet.
I did swap in a Delphi mpi conversion during the engine install, I'm beginning to eye it as the cause.