Betty the Black E21 BMW 320i

[Senor_Taylor]

Still chasing this hot start issue and popping from the exhaust. I ordered new injectors and a tool to adjust the fuel trim. Without the lambda sensor plugged in, my O2 readings bounce between .3 and .7 a volt with .45 being stochiometric, so I believe this is correct as the frequency valve should be operating at the default duty cycle. Even with this, I still get a pretty rhythmic "pop" out the exhaust like it's running too rich or lean at idle and I get a "pop pop pop" when decelerating in gear. This could either mean too lean or too rich. I can not find any vacuum leaks and I've replaced a lot of hoses.

I'm getting a cold start injector cleaned right now, so that's my next course of action. After that, I may replace fuel lines to see if they are sucking air. Beyond that, maybe I'll try to replace the fuel accumulator (not sure how yet since this part is NLA) and replace the fuel filter again since I replaced it when I got it running again, but I assume i've shaken up a good bit of 30 years of dirt and rust from the tank at this point.

I've got spares of the WUR and some other fuel system parts that I may swap around, but I want to be sure I'm methodical with this. The car runs and drives fine after all, I can just tell something is wrong from the sound of the exhaust and the hot start issues. Other than that, it's fine, and I'm not sure those two are related.