Losing my mind over this misfire issue
04-10-2019, 05:36 PM
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Join Date: Apr 2019
Location: Cincinnati area
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Losing my mind over this misfire issue Hello all, first time poster here.
I have quite the peculiar trouble occurring with my fresh 5.3 swap. Before I go into detail what's happening, heres what all has been done.
Stock bottom end 5.3, fully rebuilt,
rod, main, and cam bearings as well as the rings were all replaced
Block was honed and hot tanked
Stock pistons, rods and crank
Heads are decked .020 ported and polished 862 with double valve springs and trunion upgrades
Cam is a 220/224 .575/.575 112 lsa with ls7 style lifters
Trickflow .080 wall pushrods set to correct length from a reliable builder in my area
Stock ls1 intake and throttle body
Billet fuel rails and deatschwerks 42lb injectors
Speed engineering 3rd gen fbody swap headers
Harness made by myself and ecm from donor truck tuned for injector data and vats removal. I dont have hptuners it was done by a friend
Parts replaced with new
New coils, wires and spark plugs
Crank and cam sensors
Both o2 sensors replaced with new denso sensors
Ect sensor
New coil harnesses
Parts retained from donor truck
Maf sensor
Map sensor
TPS sensor
Iat sensor
The problem I'm running into is a pretty consistent misfire on any kind of load past idle and no load revving when in closed loop. When I take it out onto the street I start to give it throttle and I can watch the bank 2 long term trims max out an it starts to miss and carry on. Most of the external parts replaced were in an attempt to fix the issue. I feel like I have it pretty much narrowed down to a faulty ecm but before I go jumping to conclusions and wasting more money I'd ask around. Any help will be greatly appreciated and if anyone needs any more info I can help as much as I can. Most all of the work was done by myself. Much appreciated.
I have quite the peculiar trouble occurring with my fresh 5.3 swap. Before I go into detail what's happening, heres what all has been done.
Stock bottom end 5.3, fully rebuilt,
rod, main, and cam bearings as well as the rings were all replaced
Block was honed and hot tanked
Stock pistons, rods and crank
Heads are decked .020 ported and polished 862 with double valve springs and trunion upgrades
Cam is a 220/224 .575/.575 112 lsa with ls7 style lifters
Trickflow .080 wall pushrods set to correct length from a reliable builder in my area
Stock ls1 intake and throttle body
Billet fuel rails and deatschwerks 42lb injectors
Speed engineering 3rd gen fbody swap headers
Harness made by myself and ecm from donor truck tuned for injector data and vats removal. I dont have hptuners it was done by a friend
Parts replaced with new
New coils, wires and spark plugs
Crank and cam sensors
Both o2 sensors replaced with new denso sensors
Ect sensor
New coil harnesses
Parts retained from donor truck
Maf sensor
Map sensor
TPS sensor
Iat sensor
The problem I'm running into is a pretty consistent misfire on any kind of load past idle and no load revving when in closed loop. When I take it out onto the street I start to give it throttle and I can watch the bank 2 long term trims max out an it starts to miss and carry on. Most of the external parts replaced were in an attempt to fix the issue. I feel like I have it pretty much narrowed down to a faulty ecm but before I go jumping to conclusions and wasting more money I'd ask around. Any help will be greatly appreciated and if anyone needs any more info I can help as much as I can. Most all of the work was done by myself. Much appreciated.
