I just installed a AEM Uego wide band air/fuel gauge. It goes total lean at Idle in park but the gauge only shows from 10.0-18.0. When I'm driving normal and just trying to maintain a constant speed it shows between 14.6 and 15.3. At WOT it shows between 12.2 and 13.2(jumps around in between those numbers). I've only taken it out for a 10 min test drive with the new gauge but do this numbers seem ok? It was dyno tuned for 12.5 @ WOT. mods in sig

 

Seems ok to me.. can try more fuel at idle unless the motor likes it. I think my buddy has that same guage and its total lean at idle too but the car is stable at idle. Same fueling in the cruise areas and mid 12's at WOT so far.

I have the LC1 with G5 gauge kit...it goes to 18 air fuel as well

 

thanks Orr, The car seems to like the fuel tune. Not sure if you remember i was having a pinging issue but that seems to be gone after having the valve guides replaced. Think I was pinging due to oil in the combustion chamber. If you remember Orr I emailed u my 2 tunes, One with 29* total timing and the other with 34* total timing. I have went back to the 34* tune and it seems to like it, no pinging and running great.

 

Yeah 34 should be where it wants WOT timing. Oil in the chamber can increase detonation chances so maybe thats what happened

 

I'am using the AEM one also, your numbers seem alright but your idle is off, does your car want to stall at all when comming to a stop or rpm hunts at idle? Maybe you can add a little in the tune to get it to register on the meter but big cam's do funny things.

 

I've always found that a good lean idle with a ton of advance (24-26*) makes for the smoothest idles on a big cam motor.

Although, I run a manual trans. With an automatic it might not be acceptable to idle at 900-950rpm if it's a street car.

-- Joe

 

it idles pretty good a little rough but not bad, just wondering if the idle being lean could have caused my premature valve guide wear????? I dont have access to my friends laptop for tuning right now. Do u guys think if I increased the fuel pressure from 43 to like 45-46 with the AFPR it would help?

 

I wouldn't mess with the fuel pressure since everything else is in check and you already had a dyno tune done for WOT for that fuel pressure setting.

What AFR do you shoot for?

 

Yep i usually give my motors a good bit of advance...28 deg and somewhat leaner idles. My 383 was fairly comfortable at 15 to 1 and 28 deg timing at 900-950 rpm. My 401 doesnt have near the cam size but I am trying to find its happy zone. I want it at 800 idle so I am going to try lean it out to 15-16 to 1 and run 26-28 deg as well.

The heads/cam L98 i tuned likes being very lean, 750 rpm idle, and 28 deg timing as well.

 

[QUOTE=Tony89GTA;4734663]I wouldn't mess with the fuel pressure since everything else is in check and you already had a dyno tune done for WOT for that fuel pressure setting.



I went to 48psi with the fuel pressure and had no effect on my air/fuel Idle so I put it back to the 43psi it was originally at.

 

Whats your AFR after you first start it up and the engine is cold? Should show something on the meter.

 

starts at like 15 and then climbs over 18 and off the gauge in like 10 seconds.

 

Is this on a first startup? Wether its hot or cold?

Sounds exactly like how my car operated when tuning closed loop. On first startup the car will go into open loop.. depending on if its a hot start or cold start, it would idle at 14-15 to 1 like normal until getting warm enough to enter closed loop.
Once it went into closed loop, it would go lean and peg the gauge at 18 to 1 but still idle although idle rpm dropped and it wanted to die. Sometimes it did die. After alittle while however, it would eventually come back down to 15's to 1 or so. Cruise was fine, BLM's were 128 and air fuel remained in a normal 14-15 to 1 area.

So maybe you are having a similar problem where it first starts up and idles fine, but give it alittle bit of time it will go into closed loop and then go lean? After driving a few minutes and then coming to a stop does it stay in the 15 to 1 range or does it still go 18 to 1 lean?


OR it could be startup enrichment decaying out. It will start rich and stay rich for alittle while then that enrichment will decay out and go to running purely off MAF once in closed loop, or open loop tables if in open loop. Either way it still uses MAF.

If it does that, and just goes lean and stays lean no matter what...then it probably just needs MAF table 1 tweaking. I will take a look at your bin today.

 

your controller may have the aboility to average out the changes so as not be erratic. My pillar gauge changes every one second like 14.3-14.4-14.1 etc.