steelcoffinx3

I have turboed 1.5 sohc accent, the car runs great for about 10 minutes and then it starts surging under boost, feels like it misfires. Off boost feels ok, sometimes there's a bit of vibration at idle. I've tried cleaning the maf, different gas stations, lucas octane booster, ignition wire resistance seemed fine. The plugs are one step colder gapped at .032, I only have cel codes for the o2 sensor not being plugged in. The turbo is pretty close to the coil pack, maybe it's overheating it?

faithofadragon

well, concidering you didnt tell me how its tuned, who tuned it, and what tuner your using.



im just gonna assume your problems are due to the fact that the thing that monitors how rich and lean you are (o2 sensor) isnt connected

SR Tech

upstream or downstream o2?



What are you using for a tuner?



MAP or MAF based?



Any smoke out of the exhaust?

steelcoffinx3

It's untuned, it has beta 2.0 injectors and maf, adjustable fmu, and inline fuel pump. I have a narrow band hooked to the upstream o2 sensor (that's not plugged in) it reads .97-1v at wot. I noticed a little smoke when it was surging yesterday. It ran ok before it's just been getting worse.

SR Tech

What color smoke?



IMO NEVER use a narrowband for tuning, a wideband is your best friend with boost.



And yea, unless your running a tuner that keeps the ecu in open loop, that o2 is going to be your problem everytime

steelcoffinx3

I couldn't tell what color smoke it was I just saw a little in the rear view. As I said it ran better before and it actually loses a lot of bottom end with the o2 sensor plugged in.

Fintile

How much boost again? Also you need more than Beta 2.0 injectors get 290cc injectors. Not sure about the MAF Accent but also the gap needs to be brought down to about .028. Also the problem you have at idel is due to you having bigger injectors and fuel pump. I'll have to remember what I did to correct my issues with my car when it was boosted but with just an SAFC II, 290cc Injectors, .028 gap, and dissconected O2 sensors I was running clean...

MechaniX_034

Well there's your problem.

steelcoffinx3

I don't have a boost gauge but probably about 5-6 psi (the wastegate was set to 7 psi and I don't have a lot of preload on it). For the injectors, I know two turbo x3s that ran them past 10psi. I'll try gapping the plugs down to .028, I can deal with the idle (and fuel consumption) for now I just need it to run cleanly down the 1/4 mile.

03tibe85

OMGWTF? Is the OP serious? Beta2 injectors are 190cc and ARE NOT able to compensate for boost above like 1psi. ROFL...plus the O2 sensor is unplugged and reading .97 volt? WTF?



I guess there's a reason why his screen name is steelcoffin....LMAO