Thread: Car problems Leaning/richening

My 04 comp g will lean out hard enough to max out my wb and the car will bog down really bad when it does it. At WOT it'll max out my wb rich. Even leaning it out via my maf won't make it come out of it. I've tried a new maf and injectors neither help at all. Any help would be appreciated. Thanks.

Once you get HPT and license your car, I can look.

But it would be wise to flash the STOCK tune back into the car first, because then you have something to go back too. You also have to pretty much start over with HPT, you don't want to start "modding" a already changed tune.

I flashed a stock tune back to it and it made no difference.

Flash a stock tune with only the necessary things like the correct injector tables and maf tables flashed. Then do a data log including wideband so that a few of us on the forums here can take a peek at what its doing. My guess is it is either tune, maf, or fuel system related. But you could also have a vacuum leak.

I'm leaning toward vacuum leak somewhere. I flashed a stock tune to it with no difference.

Ok so if I'm idling and pump my brakes my car leans all the way out. Wtf is going on here?

Originally Posted by dsmuts

Ok so if I'm idling and pump my brakes my car leans all the way out. Wtf is going on here?

Normal.

Yes. As you pump the brake pedal you are using the vacuum stored in the brake servo. This vacuum is created by the engine in the inlet manifold. To maintain the vacuum in the servo, the air introduced by pumping the brake pedal passes down a pipe to the inlet manifold, thus leaning the mix to the engine breifly, causing the idle speed to increase till the vacuum is re-established.

And you are cammed, it's going to have a bigger affect.

It's never done it before though

You could actually very possibly have a bad brake booster. Unhook the line and plug it so you dont have a massive leak. See if your problems persist (Obviously be VERY FUXKING CAREFUL... Your brakes will be VERY hard to press)

I'll try that. I'm getting about 15ish in hg at idle so I'm not sure if that's really that low or not.

That made no difference. I'm gonna swap the o2 tonight

I'm back on my normal tune now

o2 made no difference.

Kind of a guessing game here.

If and when you set up your HPT, you can data log various things. You can log both the pedal postion sensor and throttle body %, I think. Watch fuel trims and MAF data for volts and hz. No idea if bad injector data is causing this issue.

I've already checked just about everything I can think of. My throttle position is about 6 at idle I'm not sure if that's normal or not

Wideband is brand new

If the car is running fine and your fuel trims are good nothing is wrong.

The car isn't running fine