My CRX is running really lean. Need some help

[Mad Mike]

Ok only thing that has changed other than the full rebuild of my motor. (A/F was the same as the dyno tune maybe a bit richer after rebuild)

My 14B blew and I replaced it with a good 14B now the A/F wont go below 13s on my AEM wideband.

I'm going to put in some new NGKs tomorrow. What else could of caused the A/F to go lean. Could it be my stock map sensor died?(no CELs)

thanks

[scttydb411]

if the old turbo was binding and not allowing as much air through and now it's flowing more air because it's a newer, better turbo, then it'll be leaner.

[Mad Mike]

thats what I was thinking. When I pulled the old one off and spun them both the new one spun a lot better.

I'm going to replace the HF manifold, my homemade downpipe and my crappy exhaust with better flowing ones and then will get it retuned.

[Mad Mike]

I drove it today and the A/F was dead on at all boost. Started driving it around 5pm and then parked it for a few hours. When I left I drove it easy until the temp came up (I always drive it easy or let it warm up some before driving) It was 10pm and after the temp came up I got on it and the A/F was off again. It wouldn't go below 13s and would get worse as the boost came up.

I know the new 14B has to do with it but what would cause the A/F to be good at 5-7PM and suck at 10-11pm. The outside air temp really didn't drop that much.

:thinking:

[scttydb411]

could be a voltage problem (ie: lights drawing current away causing the injectors/pump to sag).

[Mad Mike]

It could be but the first time it did it was during the day time on the mountain. No lights where on at the time.

[turbob20]

there is different types of air in cubic feet. theres hot humid conditions that add to the under hood temps, theres cold crisp air, moist damp air and as you go up and down in elevation the air gets thinner up high than down low and even if the air temp drops 2 degrees the air at night in some places becomes denser and heavier.id just get a touch up tune and see what the lap top says

[Mad Mike]

Yea I'm going to get it retuned soon. I'm about to replace my exhaust and manifold with some better flowing stuff and then get it retuned.

[TSiFTW]

You would be surprised at the difference in 82 degree midday heat and 75 degrees when the sun goes down. The cooler more dense air at night was causing the lean condition. My car is a night and day difference when the sun goes down.

[TSiFTW]

What size injectors and fuel pump are you using.

[Mad Mike]

450cc dsm blue tops and a webro255 intank pump.

[KevinT707]

I'll race you once you get your problems fixed :D

[turbob20]

opening that exhaust up will relieve alot of back pressure on the turbo and help effenciancy also will lean it even more so dont hammer on it too hard till you retune!