Consider plug wires as well. However, since it burns oil, plugs would be my first GUESS as well.
Eric Schieb Stephanie Turner wrote: > Replace spark plugs. A misfire under boost does exactly as you describe. > Make sure all are gapped properly and evenly. > > Stephanie > > BEGi/Bell Engineering > Phone: 830-438-2890 > Fax: 830-438-8361 > www.bellengineering.net > > > -----Original Message----- > From: [email protected] [mailto:[email protected]] > Sent: Tuesday, October 13, 2009 12:11 PM > To: [email protected] > Subject: 1990 CEL 17 Good idle, bad load > > Hello all, > > Hopefully someone can help guide me in the right > direction in getting my '90 working again. Bear with > me on the TMI/ TLDR. Short run - stubles, lugs and > stalls under load and I suspect an injector issue but > am looking for some second opinions which are > encouraged. Any thoughts or ideas are welcome, please! > > Symptoms: > Under load the O2 reading drops to full lean (and > frequently so low that it doesn't register on my O2 > gauge) and the engine stubles and feels like it's > missing. Under sustained load (more than 10-15 > seconds) it's incredibly low on power, stutters, > lugs, chugs and otherwise threatens to stall. I held > onto it like this long enough to throw a CEL code 17 > which apparently is "Oxygen sensor (output not > changing)," which is pretty obvious considering the > activity of the gauge and provides no actual clue as > to the cause. > > Thoughts: > Engines need air, fuel and spark. I cleaned the air > filter and don't have a AFM code on the CEL so air > doesn't seem to be the problem. It starts immediately > and runs fine at idle which doesn't really indicate > spark. I suspect it's a fuel delivery problem but > with the FP readings it seems that the fuel delivery > to the rail is working fine. This leaves me to > suspect an injector issue. > > Indications: > 1. Good idle > 2. O2 dithers properly at idle once the sensor warms > up (about 1 minute after starting). Using a Bosch > heated sensor from FM (about 8-10 years old). O2 > readings from an Autometer LED style gauge vampire > tapped at the ECU. > 3. Engine starts cleanly (I do have the occasional > issue with the starter solenoid, but unrelated to the > issue) > 4. Engine burns a shitpot of oil from bad valve seals > at start, blue smoke from worn rings over 4K RPM. > 5. Fuel Pressure is good, 32 PSI closed throttle, 42 > PSI WOT. It's a little low, but has read like this > since I installed the gauge 12 years ago. The sender > is tapped into the end of the fuel rail so gauge > pressure = rail pressure. > 6. Air filter is clean, it was my first (easiest) > trouble shooting step considering the problem > > > > > _______________________________________________ > Miatapower mailing list > [email protected] > http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower > > _______________________________________________ > Miatapower mailing list > [email protected] > http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower > > _______________________________________________ Miatapower mailing list [email protected] http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower
