I seem to have a studder or stumble at around 1500 rpm. It's more noticeable in lower gear ranges and doesn't seem to be an issue at highway driving speeds in 5th and 6th gears. If I hit the pedal while in that range in a low gear the power is not instantaneous and seems to stumble for a split second before revving up - a symptom I don't notice at slightly higher rpms like 2K or above.
Even without a load on the engine I feel a slight miss or issue around that rpm range. Car mods are the VMP BAP along with the VMP Gen2R Budget kit which was the Gen2R with JLT 123mm CAI, VMP 67mm throttle body, and DeatschWerks 95lb (1000cc) fuel injectors. I also have the VMP triple pass HE, IR plugs, 2012 exhaust system installed and a few other options that should really be irrelevant. The plugs, MAF sensor and throttle body were swapped out and made no difference. Mechanically the only engine component replaced was the crankcase sensor a few years ago due to oil leakage.
I have a Cobalt vacuum / boost gauge installed and have the correct vacuum and boost readings at idle and max rpm with no unusual gauge readings when passing the 1500 mark. Tuner said he didn't notice any issues but he isn't driving it all the time. Of course there are no errors logging.
Any ideas or tips on the most likely issue? Tuning issue still? Swap injectors?? Injectors are clean and only have 5K - 10K on them. Fuel shouldn’t be an issue, 93 Shell used all the time.
Even without a load on the engine I feel a slight miss or issue around that rpm range. Car mods are the VMP BAP along with the VMP Gen2R Budget kit which was the Gen2R with JLT 123mm CAI, VMP 67mm throttle body, and DeatschWerks 95lb (1000cc) fuel injectors. I also have the VMP triple pass HE, IR plugs, 2012 exhaust system installed and a few other options that should really be irrelevant. The plugs, MAF sensor and throttle body were swapped out and made no difference. Mechanically the only engine component replaced was the crankcase sensor a few years ago due to oil leakage.
I have a Cobalt vacuum / boost gauge installed and have the correct vacuum and boost readings at idle and max rpm with no unusual gauge readings when passing the 1500 mark. Tuner said he didn't notice any issues but he isn't driving it all the time. Of course there are no errors logging.
Any ideas or tips on the most likely issue? Tuning issue still? Swap injectors?? Injectors are clean and only have 5K - 10K on them. Fuel shouldn’t be an issue, 93 Shell used all the time.