When my car (top-swapped L36 in a GTP) gets hot, such as when driving a long distance or sitting in traffic, it gets to a point where when I give it more than 20 percent throttle, it just stumbles and bogs down and loses any power and starts slowing; and if I floor it during the stumbling, nothing changes. It also builds a little boost (maybe 2 pounds) while it's stumbling/bogging down. It doesn't get any better or worse unless I get off the throttle all together. Last time it did this, it threw an o2 code, so I replaced the o2s (just about a month ago) and it's seemed fine since then, but I haven't been stuck in traffic since then either.
Boost bypass? TPS? Bad fuel pump? Crank/cam position sensor? The fuel pump is pretty loud, much more than other cars. But a fuel issue wouldn't cause boost to register on the trip computer?
It's hard to duplicate since I need to basically get stuck in traffic for a while. But if I floor it from a stop, it'll bog down until I release the throttle, and if I roll into the throttle any more than 20 percent or so from a stop, it bogs down. Takes for-freakin-ever to get up to speed when the issue is happening. Any ideas besides rolling it down a hill into the pond?
It has completely shut off twice in the past 3 months; possibly due to the same issue.
Cat is out temporarily, so it's not that.
Luckily I work off-hours and never hit traffic during a normal commute. Ugh.
Also noticed a "hissing" vacuum leak sort of sound from the brake booster after turning the car off today, but while the car is off, if I press the brake pedal a few times it gets stiff, so that's good, right?
Peder02
