Approximately four months ago I changed the driver's side header on my Buick GN. Pulled the header and had the typical crack repaired. Replaced the header (with no apparent exhaust leak) and eventually over the next week realized there was a loss of power. My symptom is......the car runs fine at idle and while driving. Apparently gets plenty of boost (17-19 lbs.) but barely spins the tires like it once did. Hooked up to Powerlogger and all the vitals appear to be in normal operating range at idle and during driving operation. Initially thought it might be vacuum related. Checked all the hoses for cracks and used the starter fluid method to verify any leaks, with negative results. The next thing I though it could be was the torque converter; so I changed the torque converter to a known good one and the symptom remain. Also replaced the fuel pump and spark plugs with negative results. Looking to see if anyone has ever experienced anything like this and could offer any advice in chasing down this dilemma. ANY help or advice would be appreciated!......
loss of power..........
- Thread starter HNIC57
- Start date
- Joined
- May 28, 2001
Post up the PL logs......
....will do! Have to grab it off my other computer used for the car. Hope I'm successful in doing so.......
.....the transmission was rebuilt about a year and half ago. However; there's always a rattle when I first start the car. Initially thought it was the torque converter but when I replaced it with another one......it still had the rattle (might be a whole other problem).
.....catalytic converter has been removed!....
...doesn't have the tire spin it used to have at WOT. Sometimes at WOT, it seems like there air rushing out from somewhere (could be my imagination though in search of a gremlin). Forgot to mentioned that also changed the cam sensor. Haven't changed the wastegate and don't believe it's a wiped cam (no real ticking outside the norm)......otherwise it drives fine. Definitely seems like a WOT issue!
- Joined
- May 28, 2001
"Forgot to mentioned that also changed the cam sensor" And you put it in 180* off?????
Like Chuck is pointing to, When did you change the CAM sensor, before or after you started having the WOT issue?
What is you boost at WOT?
What is your coolant Temp at WOT?
What is your O2 counts at WOT?
What does your TPS read when the throttle is WOT (key on)?
...I don't believe so......and the reason I say that is I used the cam sensor tool when I re-installed it. Question: if it was 180* off, wouldn't it not start?
...I do have a boost gauge and at wide open throttle and I'm up around 19# of boost at WOT. I have checked d/s header and had just had it repaired when I noticed the symptom...
- Joined
- May 28, 2001
Yes, it will start.
....if I remember correctly; I changed the cam sensor shortly before I did the header. And the reason I did, is because I was chasing some sputtering and backfiring after about 35 minutes cruising at about 70 mph. Powerlogger led me to believe it could be an ignition or fueling problem. Swapped out the coil and ignition module from my other car and still had the problem so I changed the cam sensor. Going to post up a powerlogger reading later on tonight after work. Let me thank all you guys for your input. Really appreciate it!
....well this is interesting; all I do know is that when I re-installed it, I used the cam sensor tool and set it according to when the light came on and re-positioned it in the same manner it came out. I'll have to read more about problems associated with setting it 180* out. I just assumed it wouldn't even start....
My boost at WOT........about 20#
My coolant at WOT.......about 165 degrees
My O2 counts at WOT........about .835v
My TPS readings when WOT (key on)......... 4.13v
