Inactive O2's? ls7.

[boosted Ls1]

Hope someone can help with this. I'm working my way round Efi Live and have done a number of scans and also tried several tunes I've been helpfully provided with.

The lambda's don't fire up, not a trace. I even replaced them with new one's. On just one occasion they lit up upon engine start and then switched off. The heater wires are live. Basically the car fire's up great but I can't get past a really lumpy idle that will stall if I rev the throttle. I can hear the air entering the TB but the fuel's not arriving on time. With DVT I can get a decent idle and also a decent throttle response.

I've found the various lambda settings but am not sure if they're correct. Can anyone suggest 'settings' for a stock ls7 engine that should put me in the right zone please? Until I get the lambda's working I can't progress. It's as if I need to find the 'On' switch.

Specs are, stock 'stand alone' engine, no CATS just a muffler on each bank. The lambda's are fitted into the end of a cast factory header just after the rear cylinder.

ETA: Are there any PID's I should look at?

[nonnieselman]

What wire harness are you working with?

[boosted Ls1]

Thank you. The harness is a standalone E38 loom from the US which I bought many years ago. It was for an Ultima GTR. It seems very good quality. I forget the brand.

[boosted Ls1]

I've looked at the 02 logs. On the first startup the lambdas are at 450 mv or less before crashing downwards. If I'm correct this is very lean and off the scale for a narrow band sensor. I'm going to see if the short term fuel trims reveal anything. :-)

[nonnieselman]

Post your datalog and tune

[boosted Ls1]

Thank you, I've tried several tunes all with the same result. I'll to a log tomorrow with the short term fuel trims and post that up. I'm stuck if I can't get off first base. ETA, I've just added the initial tune.

[boosted Ls1]

Here's a scan from this morning. Lambda's active for a short while only. Later the Long term fuel trims became active. I think I need a wideband to see where I need to go. I'll have to find out how to adjust the idle tables.