Kibokojoe
06-24-2016, 07:13 PM
Although this project involved my sons 91 735i e32 with the M30 engine it will also work with my 89 535i e34 with the same M30 engine.
Last fall his car began to struggle to run. Got a lot of error lights and codes to include antilock, eml and the ever so popular flashing check engine light. First code was for the O2 sensor which we replaced. Still no joy. After the O2 sensor was replaced started getting a 1222 code (lamda control) Shogun told me this was a fuel/air error lasting over 10 seconds. He said it was most likely an air leak. I used a smoker on the vacuum line from the brake booster to the intake and still no leaks. I sprayed the intake, hoses, injectors etc with carb cleaner with the engine running hoping to find the leak still no joy. Finally I noticed that the check valve on the brake booster vacuum line had a small hole in it. Evidently this model used a earlier version of the check valve that had a secondary small pipe that was capped. This had broken off and was allowing air into the vacuum line. I plugged this hole and the car started to run a little better but still struggling with the 1222 code. Ran a vacuum check on brake booster itself and found that it was not holding a vacuum. Diaphragm had ruptured. Installed a replacement brake booster and the car cleared all the codes until I drove it on a rainy day and again all the codes came back. After looking one more time for a leak I discovered the hose that runs between the intake into the brake booster also had a leak. The leak was where the hose fitting goes into brake booster grommet (part 15) I sealed this with silicone sealant. Finally all of the codes have cleared. I could not believe how small the leak was and yet it caused such a large problem. It is running so much better now. Still want replace the spark plugs and injectors and of course the brake booster grommet. Hope this helps someone in the future.
8484
Last fall his car began to struggle to run. Got a lot of error lights and codes to include antilock, eml and the ever so popular flashing check engine light. First code was for the O2 sensor which we replaced. Still no joy. After the O2 sensor was replaced started getting a 1222 code (lamda control) Shogun told me this was a fuel/air error lasting over 10 seconds. He said it was most likely an air leak. I used a smoker on the vacuum line from the brake booster to the intake and still no leaks. I sprayed the intake, hoses, injectors etc with carb cleaner with the engine running hoping to find the leak still no joy. Finally I noticed that the check valve on the brake booster vacuum line had a small hole in it. Evidently this model used a earlier version of the check valve that had a secondary small pipe that was capped. This had broken off and was allowing air into the vacuum line. I plugged this hole and the car started to run a little better but still struggling with the 1222 code. Ran a vacuum check on brake booster itself and found that it was not holding a vacuum. Diaphragm had ruptured. Installed a replacement brake booster and the car cleared all the codes until I drove it on a rainy day and again all the codes came back. After looking one more time for a leak I discovered the hose that runs between the intake into the brake booster also had a leak. The leak was where the hose fitting goes into brake booster grommet (part 15) I sealed this with silicone sealant. Finally all of the codes have cleared. I could not believe how small the leak was and yet it caused such a large problem. It is running so much better now. Still want replace the spark plugs and injectors and of course the brake booster grommet. Hope this helps someone in the future.
8484