Author Topic: M42 Inconsistent Air Fuel ratio- How to fix? (Read 3939 times)

Ittybittybeemer · « **on:** January 28, 2009, 08:32:02 PM »

Hi all: I just joined your Club after buying a 1995 E36 318i . Yesterday I had the computer remapped and chipped with much success (up to 142 hp at the wheels) on a new Mustang chassis dyno. Both in the initial run and after the chip mods we had the strange anomally of the engine running lean (15.1 to 1) from 4000 RPM to 5300 RPM and then it was back to 13.5 to 1 all the way to shut off at 6300RPM, just like from start to 4000 RPM. There was a dip in the hp curve and a torque wave in that lean zone, and now that I know it is there I can feel it- sort of a flattening out. Anyone any idea what is causing this? thanks very much.

xwill112x · « **Reply #1 on:** January 29, 2009, 09:12:19 AM »

air filter, fuel filter, fuel injectors, clean, and fuel pump good?

B318M42W · « **Reply #2 on:** January 29, 2009, 11:13:34 PM »

more thinking mass air flow meter...

Ittybittybeemer · « **Reply #3 on:** January 30, 2009, 09:31:20 AM »

Thanks. Everything is clean and new plugs were installed. I had also thought mass air flow meter. How do I test forthis?

Thanks

Ittybittybeemer · « **Reply #4 on:** January 31, 2009, 08:08:31 PM »

Ther was a 1 inch crack in the underside of the rubber unit between the Injector and the MAF. I found one on a parts car. Case closed. Thanks.

Ittybittybeemer · « **Reply #5 on:** February 03, 2009, 11:10:50 PM »

Well, it was not quite solved. Despite a new boot that was not cracked when we put it back on the dyno there was still a blip that was lean. But Dan Miller (Miller Performance- Abbotsford BC (http://www.millerperformancecars.com) was able to remap to add more fuel where required. The Power and Torque curves now look right, and feel even better.