smoke, missfire & code 51

robertsws · 05-26-2008, 01:13 PM

I've got a 91 turbo i just bought with 93,000 miles on it. the last owner installed a 3" exhaust, k&n air intake, upgraded blow off valve, and a SAFC 2.

since i got it i changed the spark plugs, TPS, cleaned, inspected and checked the TB, O2 sensor, ICV, and all vacuum lines both at idle and under load.

My problem(s) is that though it is running much better, I've got white smoke on deceleration (BHG maybe), a steady missfire around 4000 RPM until warmed up then it's not nearly as bad, a code 51 when i mash it or when i'm running the A/C then it's a steady 51.

Also if i adjust the SAFC 2 down to 22 on the LO and 14 on the HI i've got no steady missfire (just an occasional missfire and backfire when getting on it) and plenty of power, but it smokes more and stinks plenty when i do that.

What am I missing? I just can't figure it out. I'm thinking maybe timing, it also has a new timing belt so maybe it was timed wrong.

05-26-2008, 01:13 PM	#1
robertsws 3" Exhaust Join Date: May 2008 Location: Gaithersburg, Maryland Posts: 63	smoke, missfire & code 51 I've got a 91 turbo i just bought with 93,000 miles on it. the last owner installed a 3" exhaust, k&n air intake, upgraded blow off valve, and a SAFC 2. since i got it i changed the spark plugs, TPS, cleaned, inspected and checked the TB, O2 sensor, ICV, and all vacuum lines both at idle and under load. My problem(s) is that though it is running much better, I've got white smoke on deceleration (BHG maybe), a steady missfire around 4000 RPM until warmed up then it's not nearly as bad, a code 51 when i mash it or when i'm running the A/C then it's a steady 51. Also if i adjust the SAFC 2 down to 22 on the LO and 14 on the HI i've got no steady missfire (just an occasional missfire and backfire when getting on it) and plenty of power, but it smokes more and stinks plenty when i do that. What am I missing? I just can't figure it out. I'm thinking maybe timing, it also has a new timing belt so maybe it was timed wrong.