2g GST MT dieseling, no power

[EVO9_Inside]

My friend has a 95 GST MT that weve been trying to fix for a few days now, Mostly because its MY driveway hes craped out in. he pulled in saying he had a dieseling problem and NO low end power.
test drive had these problems, 02 engine light code, horrible low end power, it feels to be within about 50hp? no boosting even with turbonetics boost controller and no play with the 14b turbo shafts. Then as we crested the hill into my street the car died in all sense of the automotive word, it crawlllleeeddd over the top of the hill and rolled into my driveway sounding like a raggad dog and when i turned it off it dieseled for about 5 cranks and almost tried to restart(normal for the car).
plug and wires, new, head new, oil freshly changed but when he bought the car it had a watery viscosity(not coolant water, just thin thin oil).
i checked his oil, no bearing bits, timing was checked, its dead on.
ideas?
i run a 1g 6 bolt with evo9 bits with a 16g, thats my backround into these cars, but my problem is i bought a shell and built it from the ground up, so i dont know about parts wearing out on these cars yet.

thanks for any input and all ideas will be tried because i hate driving on my grass to get out of my home...

 

[everydaydriven]

Strange but sounds like you might have a boost leak somewhere. Or maby the crank or cam sensor has taken a poop. I'd start with a boost leak test, see where that leads ya. All else maby check the fuel filter strainer an the pump next.
Thanks,
Jake

 

[97gst_spyder]

Are the spark plug wires in the correct locations? Check the timing....

 

[tenn-gsx]

Im gonna say that the issues are probably all related to the o2 sensor. The car is probably extremely rich. This floods the engine causing the cylinders to get fuel soaked. Your plugs are probably all fouled out and the carbon deposits from running rich will cause hot spots. Fuel soaked cylinders with hot spots are suceptable to dieseling. Particularly if he is using low grade gasoline and or high alcohol/methanol content. There are several other causes of dieseling but that would be my guess on these cars. Steps I would take to fix your car.
1. A can of sea foam.
2. New plugs.
3. Need o2 sensors
4. Boost leak test
5. Fix any and all boost leaks.

I would be surprised if its still having the power loss and dieseling issue if you do these things.