KJ-6G75
27-06-2014, 11:01 AM
Hi guys,
I posted a little while back about a surging problem that’s been driving me crazy. I’d appreciate any advice you may have. I’ve had a lot of parts replaced recently, so I feel like that should narrow down the possibilities. Car is a 2002 Auto KJ Verada with duel fuel.
Description of the problem:
Rough surging when car is under heavy acceleration. Whole car lurches forward and back.
Has been occurring for at least 6 months. Doesn’t seem to have gotten much worse over time.
Car idles normally.
Only happens when car is warm (been driven for half an hour or so).
Will happen whether accelerating from a standstill or accelerating from 60 km/h.
Haven’t noticed the problem while car is running on LPG – Only petrol.
Revs increase but car goes nowhere. Feels like the transmission is struggling to shift gears.
When gears change I've been hearing a "whoosh" from the exhaust that's similar to how a blow off valve sounds. Can't remember if it was there before, but it's reasonably loud.
Car occasionally will backfire while it happens.
Recently (last few weeks) after the car is driven hard I’ve noticed the exhaust sounding a bit different. Could describe it as sounding more like a “muscle car” while idling. Can be heard in the cabin quite easily.
Problem has never triggered a check engine light.
Things that have been done in the last two months:
Automatic transmission flushed/serviced – No problems noted.
3.8L 6G75 engine installed about a month ago by Mal and Brendan at Mits-Fix.
Injectors cleaned.
Spark plugs and leads replaced.
Throttle body/TPS checked.
MAF replaced.
O2 sensor replaced.
Entire distributor including ignition coil replaced.
Intake manifold gasket replaced.
Fuel pump and filter replaced, fuel lines flushed and tank cleaned. This reduced the problem considerably. It used to happen after 10 minutes of driving, and it now takes around 30 minutes.
Catalytic converter replaced.
Video of problem:
This is accelerating from a standstill to around 90km/h with just below full throttle. While the revs spike the whole car is surging back and forth. Throughout the video I have my foot in the same position on the accelerator.
http://videobam.com/QjMkU
I posted a little while back about a surging problem that’s been driving me crazy. I’d appreciate any advice you may have. I’ve had a lot of parts replaced recently, so I feel like that should narrow down the possibilities. Car is a 2002 Auto KJ Verada with duel fuel.
Description of the problem:
Rough surging when car is under heavy acceleration. Whole car lurches forward and back.
Has been occurring for at least 6 months. Doesn’t seem to have gotten much worse over time.
Car idles normally.
Only happens when car is warm (been driven for half an hour or so).
Will happen whether accelerating from a standstill or accelerating from 60 km/h.
Haven’t noticed the problem while car is running on LPG – Only petrol.
Revs increase but car goes nowhere. Feels like the transmission is struggling to shift gears.
When gears change I've been hearing a "whoosh" from the exhaust that's similar to how a blow off valve sounds. Can't remember if it was there before, but it's reasonably loud.
Car occasionally will backfire while it happens.
Recently (last few weeks) after the car is driven hard I’ve noticed the exhaust sounding a bit different. Could describe it as sounding more like a “muscle car” while idling. Can be heard in the cabin quite easily.
Problem has never triggered a check engine light.
Things that have been done in the last two months:
Automatic transmission flushed/serviced – No problems noted.
3.8L 6G75 engine installed about a month ago by Mal and Brendan at Mits-Fix.
Injectors cleaned.
Spark plugs and leads replaced.
Throttle body/TPS checked.
MAF replaced.
O2 sensor replaced.
Entire distributor including ignition coil replaced.
Intake manifold gasket replaced.
Fuel pump and filter replaced, fuel lines flushed and tank cleaned. This reduced the problem considerably. It used to happen after 10 minutes of driving, and it now takes around 30 minutes.
Catalytic converter replaced.
Video of problem:
This is accelerating from a standstill to around 90km/h with just below full throttle. While the revs spike the whole car is surging back and forth. Throughout the video I have my foot in the same position on the accelerator.
http://videobam.com/QjMkU