Boris3 Posted May 3, 2014 Report Share Posted May 3, 2014 So the 1991 318is, has gone from an intermittent cel flash to today flashing any time I'm on the throttle. Standing or moving. No cel on idle. Bavarian Auto code reader shows no codes. Ideas? Quote Link to comment Share on other sites More sharing options...
0 B C Posted May 3, 2014 Report Share Posted May 3, 2014 Do a stomp test http://www.unofficialbmw.com/repair_faqs/motronic.html Quote Link to comment Share on other sites More sharing options...
0 Boris3 Posted May 3, 2014 Author Report Share Posted May 3, 2014 Did one and got 1444, no codes. Flashing cel only happens when I hit the throttle. In gear on the road or just sitting with the MT in neutral. Quote Link to comment Share on other sites More sharing options...
0 B C Posted May 3, 2014 Report Share Posted May 3, 2014 Is the car misfiring at all?The only thing I can think to do at the moment is check the battery voltage, computers can get all sorts of "out of limits" readings and other wonkyness when it gets low. Quote Link to comment Share on other sites More sharing options...
0 Boris3 Posted May 3, 2014 Author Report Share Posted May 3, 2014 Not on throttle. Idle stumbles at times. The question I have us why with the cel flickering no stored codes? Searching a bit suggests that maybe a loose/bad main relay, cps going, fuse able link though this would mean no cel...I am leaking oil from the m42 filter housing, and or something else is causing things to get wet on that side. I have to top off the radiator fill tank about an inch every few weeks to the kalt line. Maybe something is getting blown around into electronics? Quote Link to comment Share on other sites More sharing options...
0 Boris3 Posted May 4, 2014 Author Report Share Posted May 4, 2014 Today idle rougher, runs, almost dies, runs etc. Checked connectors, swapped out relays, replaced fuel filter (needed it), no difference. Quote Link to comment Share on other sites More sharing options...
0 Boris3 Posted May 7, 2014 Author Report Share Posted May 7, 2014 After unplugging assorted things the issue may be the O2 sensor even though throwing no codes. Smooth idle cold, after a few minutes stumbles, cel flashes and almost dies. Disconnect O2 sensor and idles smoothly, give it throttle still runs smoothly but cel flashes. Cel flashes on throttle with or without O2 sensor connected. No codes stored. Think it's time to try a new O2 sensor.Coil packs check out fine, cps as well, cam sensor, tps and icv, afm (tried with and without the resistor harness).Replaced fuel filter, spark plugs, intake boot. Checked plug wires. Resistance on wire 1 is 15.33; wire 2 is 5.76; wire 3 is 5.74; wire 4 is 5.98. Meter set at 20k. Not sure what values should be.If anyone can think of something I've missed please let me know. Quote Link to comment Share on other sites More sharing options...
0 B C Posted May 7, 2014 Report Share Posted May 7, 2014 I should have a good OEM Bosch O2 sensor (15k miles use) if you want to try it out. I will have to check my parts bin but you are welcome to try it and if it works out for you can have it for $20 Quote Link to comment Share on other sites More sharing options...
0 Boris3 Posted May 7, 2014 Author Report Share Posted May 7, 2014 Thank you sir. Bought one this morning. Haven't installed it yet. Did find one possible intake leak source. One of the multiple hose pieces between the crankcase and the throttle body on the m42 the only one I hadn't replaced turned out to be cracked. I picked up some crankcase hose when I bought the sensor and will try that first to see if it makes a difference. Quote Link to comment Share on other sites More sharing options...
0 B C Posted May 7, 2014 Report Share Posted May 7, 2014 I also have a very janky yet effective smoke tester i put together a couple years ago that you are certainly welcome to use Quote Link to comment Share on other sites More sharing options...
0 Boris3 Posted May 7, 2014 Author Report Share Posted May 7, 2014 Been thinking it would be handy to have one of these and had been looking at the diy versions. If no progress with the hose and O2 sensor I'll be in touch! Quote Link to comment Share on other sites More sharing options...
0 Boris3 Posted May 8, 2014 Author Report Share Posted May 8, 2014 Hose replaced, smoothed it out a bit. O2 sensor replaced, smooth idle cold and warm with no CEL. Give it throttle and cel flashes, no stored codes. Even checked the bulb to see if it was loose. All good. I'm stumped. Car runs fine. I've got an oil leak at the filter housing maybe this? Quote Link to comment Share on other sites More sharing options...
0 B C Posted May 8, 2014 Report Share Posted May 8, 2014 Does it depend on how aggressively you accelerate? (AFM pegging out),Does it depend on the RPM range you are in?(O2 sensor losing connection), Does it only occur at a particular throttle position? (worn spot on the TPS) If it were related to the Main ECU relay having a bad connection/loose relay the car would stumble when it happendBUT, it may be worth checking into the o2 sensor relay since the car would still operate normally under open loop and perhaps a code for o2 heater voltage or o2 signal wouldnt be stored because the duration of the malfunction isnt long enough. This is just me theorizing and thinking out loud, some ECUs require a certain number of malfunctions within a certain timeframe to store a code and a certain number of start cycles with no malfunctions present to clear the codes so having a time/duration based code storage criteria is something that makes sense to me as a possibility (my theory/me thinking aloud).I am also curious as to whether it is AFM related, such as a dead spot on the resistor track or a weak spring, or a wiper arm that needs adjustment since a vacuum spike within the intake tract while accelerating could peg out the AFM with one of those problems and cause it to read out of limits. Quote Link to comment Share on other sites More sharing options...
0 Boris3 Posted May 8, 2014 Author Report Share Posted May 8, 2014 Tried smooth and hard acceleration and same result. Needed a muffler shop to get the O2 sensor out. On the way home cel would flash but under load up a steep hill doing 35-40 did not flash. Once on a more level grade would flash. This might mean something but I'm not sure what.Rpm range flash starts around 1500 and will flash up from there. Highest I revved it was over 4k, and still flash.Swapped out the O2 sensor relay early on but since it didn't make a difference put the original back in. Since the O2 sensor has been changed I'll try th Quote Link to comment Share on other sites More sharing options...
0 B C Posted May 8, 2014 Report Share Posted May 8, 2014 Does it happen on a cold engine during warmup enrichment? When you hear of a blinking CEL under load with no stored codes that initially makes me think misfire but you say its running good. Have you tried disconnecting the battery for a few minutes to reset the ECU? Quote Link to comment Share on other sites More sharing options...
0 Boris3 Posted May 8, 2014 Author Report Share Posted May 8, 2014 Stupid smart phone... I'll try the new relay.Could be afm. I've been driving on Milwaukee roads with lowered suspension enough to rattle teeth. Maybe something knocked out of whack.A quirk in the ecu itself? I've got an extra one I can try. This uphill on a steep grade though has me curious. Quote Link to comment Share on other sites More sharing options...
0 Boris3 Posted May 8, 2014 Author Report Share Posted May 8, 2014 The engine hasn't been cold since the new O2 install. Prior the cel would flash on throttle cold or warm. Quote Link to comment Share on other sites More sharing options...
0 Boris3 Posted May 8, 2014 Author Report Share Posted May 8, 2014 Also the resistance on plug wire #1 seems out of range-- triple what I was getting on the others when I could get a reading. The others would measure easily. Quote Link to comment Share on other sites More sharing options...
0 Boris3 Posted May 8, 2014 Author Report Share Posted May 8, 2014 Anyone have a set of e30 318is plug wires I could try? Even just the #1 wire. Quote Link to comment Share on other sites More sharing options...
0 Boris3 Posted May 9, 2014 Author Report Share Posted May 9, 2014 Well... Maybe solved. Still same cel issues this morning, cold and engine warm. Except when going up a steep hill with throttle.Gas gauge showed about 3/8 of a tank and I hadn't added any since this mess began in case I had to pull the pump. So added a container of HEET, put in 5 gallons of 93 from the local SA. No change for about 10 minutes then I got on the throttle hard, cel blinked for a bit then stopped blinking. Drove around for about a 1/2 hour fine. Turned it off for about 10 minutes. Started again and ran it again for a 1/2 hour. Side streets and highway. Fine. No cel.Letting it sit for the rest of the afternoon and we'll see what happens later. Like I said maybe... Quote Link to comment Share on other sites More sharing options...
0 jc43089 Posted May 9, 2014 Report Share Posted May 9, 2014 +1 for redline action! Keep it cleaned out good. Quote Link to comment Share on other sites More sharing options...
0 wasnt m3 Posted May 9, 2014 Report Share Posted May 9, 2014 Maybe it was just some bad gas Quote Link to comment Share on other sites More sharing options...
0 Boris3 Posted May 10, 2014 Author Report Share Posted May 10, 2014 Sat for 5 hours, just took it out again. All good at idle and at speed. Go figure. Bad gas (Shell premium though) or condensation in the tank after running it down to the warning light before I had filled it up. Add in the old O2 sensor, a few marginal hoses, older plugs. etc etc??? Quote Link to comment Share on other sites More sharing options...
0 jc43089 Posted May 10, 2014 Report Share Posted May 10, 2014 Does the shell premium have ethanol? It is getting so hard to find ethanol free gas. Quote Link to comment Share on other sites More sharing options...
0 Boris3 Posted May 10, 2014 Author Report Share Posted May 10, 2014 It does, or at least around here it does. Need to get further out of Milwaukee county these days to find ethanol free gas. Quote Link to comment Share on other sites More sharing options...
0 Derflaminflitzer Posted May 11, 2014 Report Share Posted May 11, 2014 Or just go to west allis on the corner of 76th and Lincoln. They sell 110 octane Quote Link to comment Share on other sites More sharing options...
Question
Boris3
So the 1991 318is, has gone from an intermittent cel flash to today flashing any time I'm on the throttle. Standing or moving. No cel on idle. Bavarian Auto code reader shows no codes.
Ideas?
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