cpressl90

I rebuilt my 5.7L with low oil pressure. it ran good before but now it starts up runs for a while and its seems like the ignition turns off. It looks like the throttle is too far open also . Has a 220R texas speed cam. The AFR gauge was disconnected during the log.

Thanks in advance

Mickyinks

I had something similiar and it was the crank angle sensor,, more precise the 3rd crank angle sensor i tried

G Atsma

Has it been tuned for the cam?

cpressl90

Yes, it ran perfect before the rebuild minus the low oil pressure

cpressl90

Any other suggestions?

benflynn

I have seen this be old gas, would run on start up enrichment but once it timed out it would die.

cpressl90

it has been sitting for a while, i will put some fresh gas in it to verify.
Im also going to check for a vacuum leak. its very difficult for it to idle

cpressl90

Got the gas drained out yesterday and tried to find the key to start it up. Since ive moved it looks like ive misplaced the key and have to order another one from BMW. In the meantime i was looking at the log again and noticed that once the coolant temp hits 104F the fuel trims kick in and pulls out all the fuel. Can anyone think why it would do something like this when it ran great before?

benflynn

sounds like the cold start enrichment or some clt based fueling. It still could be old gas and when that coolant based enrichment cuts off it’s too lean to run. I’ll look at a tune and see if i see it.

benflynn

After start enrichment initial adder vs ECT. I would change the gas.

cpressl90

I believe i found the issue. It appears to be a combination of bad gas and my own stupidity. Put some fresh 93 in it today and primed the fuel pump a couple times an decided to check for fuel leaks to be safe. Found a small whistler on the cross over between the rails on a AN fitting. I tightened it up and started it, ran smooth but idled at 2300 RPM. At this point i went back to thinking i had a vacuum leak again. It turned out i did have a "vacuum leak" when i installed the throttle body cable it left the blade slightly open. Need to reinstall the radiator to let it run longer but it looks like the problem has been solved. Thanks for the input