I have to back Bill on this one. His wiggle test corrected a similar issue I had before my 7500 mile road trip this summer. Never had a problem with it since.
Eric -----Original Message----- From: Bill Cardell <[email protected]> Sent: Tuesday, October 13, 2009 3:53 PM To: <[email protected]>; <[email protected]> Subject: RE: 1990 CEL 17 Good idle, bad load I'd be starting plugs and wires. Fuel pressure looks adequate, although your description of full lean at WOT matches up with fading fuel supply. Does the tacho drop unrelated to actual rpm when this happens? If so, do a good wiggle test on the wires going from chassis to coils and CAS. Those wires get tugged every time you roll on and off the gas or shift, so they tend to break on older high mileage cars inside the harness. Bill Cardell TurboDog's Dad www.flyinmiata.com www.fmwestfield.com Sales 1-800-359-6957 Tech 970-464-5600 Before you call, check out http://www.flyinmiata.com/FAQ/ -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Tuesday, October 13, 2009 11:11 AM 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
