Ok, here's what's going on. I've noticed the last few drives when the car is warmed up some very slight stumbling at idle and also when first taking off. Once rpms up, car pulls as typical, doesn't seem to skip a beat. Drove it long distance, 2 trips over 100 miles and on the second trip I noticed the slowdown light flicker on twice, once on decel and once on acceleration up near 6K rpm. Not on more than 1-2 seconds and that was it. Never happened previously or since then. I noticed at the end of the drive more stumpling on decel to idle and at idle, almost to the point of dying. I increased idle from my typical 9K to about 1000 rpms to see the results of doing that. No change at idle and when it got warm, more stumbling and popping, especially at the very end of the drive. Looked under the car, the cat was glowing red and was popping a bit. The car has a hyperflow with about 1K miles and X-ost the same age. Original O2 sensor and thermocouple-maybe I contaminated or damaged the sensor moving to the new cat? So, it seems to be running too rich but why. I'm not sure the slow down light flickering is due to the same problem or is a different problem(or not a problem at all, just a connector problem). The slow down light remained off on the last drive and the cat was obviously very hot, I assume over the threshold to activate the light. I'm going to unhook the oxygen sensor to see if the problem corrects itself. I'm concerned the cat might be messed up from the poor running condition as well. Precat testing of the concentrations would make sense as been suggested previously. Any thoughts on the cause? Many of the possible causes listed in a previous thread by Brian C could be ruled out I'd think due to the problem really being on idling, not acceleration. Could a faulty O2 sensor be the entire problem? Doesn't seem like it from other postings here. Thanks Jeff
I would check the switch at the throttle body. I had a friend with the same problem and it was the switch not closing when you don't have your foot on the accelerator. With the engine shut off you should hear the "click" as soon as you move the accelerator cable. If it's not working, then the electronics "think" that you are accelerating and it advances your iginition, even if the engine is idling. That's not good .... Also please be carefull with those hot cats! If you're going to start it again please have a fire extinguisher ready !
Pull your spark plugs. Photograph them with your camera phone, and post the pics here. See the spark plug thread below in my signature, too. You may be able to identify *where* your problem is most severe this way. You probably are *not* running rich. The popping on decel is probably from running too lean...lean enough for at least one cylinder to misfire, giving you a stumble or rough idle and sending an entire cylinder's worth of unburned fuel directly into your cat(s). Definitely a fire danger!
I do plan on removing the spark plugs and will plan on posting the pictures. The car's recent history is new ignition wires/distr-rotors/plugs and extenders in 2002, a few extenders replaced in 2004 and new plugs and a fix of one coil wire in 2006 with the major. What is the lifetime typically of ignition wires and extenders? Coils could be original, I don't have records from new, but what is there life expectancy? Rui, I'll check the switch you mentioned as well. You say with the car off/no power/ it will click with accelerator depression, correct? Thanks for the responses. Jeff
Some additional questions from info gathered while searching. 1. The metering valve-should be buzzing with the car running, also should it buzz with the ignition in the run position? Car is running like on one bank only now, if that is so, I assume the metering valve is not the problem, correct? 2. How can I determine I'm running on one bank? 3. Flywheel sensor, only one in an 89 328 so couldn't be the problem if one bank gone, correct? 4. If one bank out, coil or coil wires would be a primary suspect, right? Switching the wires to the coils and a change in the bank running would confirm a coil is bad, if no change could be wire, rotors or their connections. Is this correct thinking? Thanks Jeff
1 - Yes, the FV is not the problem is one bank has no ignition. With just the key in the "on" position, the FV will not buzz. You must also either unplug the safety switch or depress the airflow metering plate while the key is "on" (both actions "open" the safety switch contacts and gives +12V power to run the injection ECU which runs the FV -- when things are working correctly). 2 - timing light on the spark plug wires to confirm/deny spark presence on each bank. 3 - correct, (unlike an injected 308) a bad flywheel sensor on a 328 can't cause just one bank to lose ignition. 4 - correct
Thanks for the responses. Regarding the metering valve, it were failing or not getting enough voltage, what would the symptoms be typically? Jeff
If the metering valve (aka frequency valve) isn't buzzing/working, the idle A/F ratio will be wacko (lean IIRC -- although maybe I'm recalling what happens with a dead EHA on a KE-Jet system) -- in any case, it will give a rough, low idle prone to stalling, and generally needing some throttle blips in order to keep the engine running (at higher engine RPMs the A/F ratio will still be off, but not as much as it is at idle).
Currently, that is what I'm experiencing. At cold start only 900 rpm at idle, not typical 2K+. Last week, the car seemed to idle ok at start(cold), just sputtered a bit and almost would die on decel and starting but seemed fine once rpm's are up. I haven't driven the car or really warmed it up in it's current condition. Runs very rough, like not all cylinders are working so I'm suspecting a bank is out but not sure yet, need to test ignition wires. Would this be a progressive problem worsening with time or be all or none? Would it also create a situation where unburned fuel is dumped into the exhaust system if this went out? What seems to happen with idle or prolonged decel is a lot of unburned fuel into the cat, heating it up very quickly. I think.... Jeff
A FV problem typically is all or none and could come and go suddenly/irregularly (as the +12V power comes and goes if it's flaky). There are other things (e.g., WUR) that might have a "worsening with time" characteristic, but you need to get past the simple checks first: 1. Confirm/deny ignition on both banks -- if ignition OK when problem occurs, go to step 2; if not OK, fix 2. Confirm/deny FV is buzzing or not when the problem occurs -- if buzzing when problem occurs, go to step 3; if not buzzing, fix 3. This is where it gets harder because you need some specialized (but not too expense) pressure measurement equipment if you want to DIY. Confirm/deny if the Warm-up regulator is behaving OK or not (i.e., measure the control pressure when cold and warm and the regulated supply pressure) -- if all OK, one might consider making the service adjustments (mixture screw, air bypass screw, throttle plate screw) as needed, if not OK must be fixed. 4. If you seem to pass everything in steps 1 thru 3, but still have a runability problem regardless of the adjustments, the fuel flow rates coming out the end of the individual injectors would need to be measured for equality and magnitude and low and high flow rates (but this isn't easy and requires some serious disassembly). Good hunting...
If you determine a problem with the coils, the problem could be the black power module on top. If you have a late 328 (s/n higher than 82XXX) you have the later coils (p/n 143413) but the power module BKL3B is the same for both versions. Check factory Service Bulletins (sorry mine are packed away right now) as there was one pertaining to 328 & 3.2 Mondials with "ignition irregularities". It involved installing an additional protection diode in the wiring to the digiplex. If your car is an '89, I doubt this would apply as this would have been corrected during production by then.
That is correct. When in silence you can/should hear the click as soon as the throttle moves. If you don't, either the switch is not correctly positioned or it's not working. Act directly on the throttle body, don't sit in the car and press the accelerator, you might not hear the click!
I believe the problem has been located, soon to be fixed. Rear bank bad rotor. Changing out both bank's rotors then see how it's running. Plugs changed as well. PO had two plugs that were incorrect it seems as well, I don't know how that happened. I've got a local mechanic doing the work. Thanks for the help. Jeff
