LM7 swap intermittent misfire
#1
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I'll be as short and clear as I can.
I swapped an LM7 into a BMW 3 series And everything went pretty smooth. But now that its running its giving me problems.
When I start driving it, it tends to run like crap, you can smell unburned fuel, it sounds like a tired old tractor. But if I floor it this clears up. Its really only obvious at partial throttle. WOT is pretty good and idle seems fine when it is acting this way.
The weird part is, if I drive it long enough it SNAPS out of this bullsh!t and runs great. Its like flicking on a switch, power is back and sounds goos even at partial throttle.
And then, if I kill it, and start it up again it goes back to crap until I drive it some more....
The worst part is that I've scanned it (at advanced auto) wigh their super cheap minimalistic scanner and got no codes whatsoever. And no CEL
Other info I can give about the car,
I've cleaned the injectors, the fuel filter/regulator is new (corvette one), the fuel pump is the stock BMW one, the maf is new, o2 sensors are new, ls1 Intake, new intake gaskets, I deffinately over torqued the bolts on tbe manifold trying to get it to stocp leaking when I thought that was the issue. I had the guy at lt1swap.com remove VATs and change a few things on the PCM
Thats about all the info I can think of. I hope someone has a clue as to wtf is going on
I swapped an LM7 into a BMW 3 series And everything went pretty smooth. But now that its running its giving me problems.
When I start driving it, it tends to run like crap, you can smell unburned fuel, it sounds like a tired old tractor. But if I floor it this clears up. Its really only obvious at partial throttle. WOT is pretty good and idle seems fine when it is acting this way.
The weird part is, if I drive it long enough it SNAPS out of this bullsh!t and runs great. Its like flicking on a switch, power is back and sounds goos even at partial throttle.
And then, if I kill it, and start it up again it goes back to crap until I drive it some more....
The worst part is that I've scanned it (at advanced auto) wigh their super cheap minimalistic scanner and got no codes whatsoever. And no CEL
Other info I can give about the car,
I've cleaned the injectors, the fuel filter/regulator is new (corvette one), the fuel pump is the stock BMW one, the maf is new, o2 sensors are new, ls1 Intake, new intake gaskets, I deffinately over torqued the bolts on tbe manifold trying to get it to stocp leaking when I thought that was the issue. I had the guy at lt1swap.com remove VATs and change a few things on the PCM
Thats about all the info I can think of. I hope someone has a clue as to wtf is going on