Engine keeps flooding out

[r3d e30]

My 89 325i keeps dump huge amounts of fuel into the cylinders and flooding out while driving. I have replaced the fuel pressure regulator, and the fuel injectors, but it still keeps flooding out. Any ideas what could be causing it to do that? Its an M20 B25 motor with a motronic 1.1 ecu.

[jlevie]

My first question would be what evidence do you have that says the engine is flooding out?

BTW: An 89 has Motronic 1.3 unless someone has swapped in a 153 DME.

[r3d e30]

Well I thought according to the Bentleys it was a 1.1, but I have found the Bentleys hasw been wrong before so you are probably right. You can smell the excess fuel, and if I pull the fuel pump fuse and depressurize the sysytem and then replace the fuse and then start it it clears out and starts again and will run a while before it floods out again. I was thinking pehaps a bad O2 sensor might be causing the fuel trim to run high, but I havent gotten a check engine light code for an O2 sensor.

[Ceeker]

Well I thought according to the Bentleys it was a 1.1, but I have found the Bentleys hasw been wrong before so you are probably right. You can smell the excess fuel, and if I pull the fuel pump fuse and depressurize the sysytem and then replace the fuse and then start it it clears out and starts again and will run a while before it floods out again. I was thinking pehaps a bad O2 sensor might be causing the fuel trim to run high, but I havent gotten a check engine light code for an O2 sensor.

what's the mileage on the motor; you might just have worn injectors. You may also want to check your AFM. your air to fuel mixture might be off. Any type of vacuum leak can also cause the car to run rich or stall. the dme is trying to compensate by the air leak by dumping more fuel in. Check all hoses etc.

[r3d e30]

The engine has about 300,000. But I just replaced the injectors cause I had one that was sticking open. I'll check the AFM. I have replaced several vacuum lines, but I dont believe there are anymore bad lines. There is so much fuel being dumped in that the fuel is being forced into the oil.

[jlevie]

If you can smell fuel in the oil the engine is flooding. The first thing I'd do would be to check fuel rail pressure. If that is normal I'd use an noid light to check each injector bank when cranking the engine. The pulse rate and time should be the same for both banks. If I haven't found the problem by this point I'd pull the injectors & rail, disconnect the coil wire, point the injectors into a towel and see what the spray patterns look like when cranking the engine.

[blunttech]

Im going to guess bad ecu only because this happened to me. Slapped in a new ecu and solved. but Ill agree in running all the tests mentioned first before throwing parts at it. Unless you have a buddy who will plug his ecu in for you

[accident]

incidentally if you need an ECU i have one for cheap.

[r3d e30]

incidentally if you need an ECU i have one for cheap.

Well I am going to check the AFM and O2 sensors with my DVM, run all the fuel pressure test again and check the spray pattern on the new injectors I installed. If that doesn't work I would be interested in you ECU. How much do you want for it and what did it come out of?

[accident]

let's say $35 to your door?

it came out of a 91 convertable. it's a 380, which is basically a 173 with a few extra diagnostic functions nobody cares about.

[hammer_e30]

Bentley says that a coolant temp sensor could cause it to run rich as well.

[gearheadE30]

Coolant temp sensor would cause this because the ecu will dump more fuel in for cold running/warmup, but it doesn't have enough map authority to cause severe flooding like this.

[E30is90]

Could be failing FPM

Did you replace with new or used? I had a fuel pressure regulator that was crapping out, causing flooding after turning engine off. Would leak out fuel making it difficult to restart after sitting when warm. Would cold start fine when left overnight. New FPM, no hard warm starting or smell of unburned fuel. Never had a problem while driving though, only when attempting to start warm.

[r3d e30]

I installed a new FPR. But I check the resistance of the coolant temp sensor and got an OL so I just ordered a new temp sensor from Bav Auto today. I think after I get this M20 working right I want to do an engine swap. I was thinking an M30 or M50. I'd love to to do an S52, but due to money and lack of paitence an S52 would probably be a bad idea. I have a baby due in June and I want to get this car finished by the time the baby comes so I can bring him home in my E30. I still have an exhaust system to sort out. The guy I bought the car from cut the cat and routed the exhaust out the side right behind the passenger door. Anyone know where I can get a used cat or cat shell to put on the car so I can get it passed inspection. This car was all messed up by the previous owner. He swaped out the automatic trans with a 5 speed from an 87 528E and removed the original radiator and replaced it with the one from the 528E. Now the lower radiator hose is right by the power steering pump and I keep having to replace or patch the hose that rubs against the pulley. I know I should just replace the radiator with one for a 325i but I just keeping putting it off. This car has been a labor of love. Even with all the problems I have had I like to drive this one more than my E46. Its more of a drivers car.

[r3d e30]

Ok, I replaced the ect sensor and now I am getting multiple check engine light flash codes. It flashes once then pauses, flashes twice then pauses, flashes three times then pause again and flashes twice. Then it pauses for a longer time and starts over again. Now the bentley's has a chart that displays the codes but it only shows 4 codes. What does it mean when it flashes twice the second time in the sequence?