Fuel Trims

[91BlackLaser]

Why are my fuel trims staying at 100% no matter what I do? They are like that at idle and part throttle and WOT. I have an SAFC tuning guide that says to set them up at
110%. If I lean it right out the car will almost stall and when I richen it right up the trims don't change. Anyone know why?

 

[turbo2086]

Hey you're lucky. You want them to be at 100%.

 

[tom04841]

Most likely caused by a bad O2 sensor. If it isn't cycling properly, your trims won't change.

 

[91BlackLaser]

The car has a couple broken exhaust manifold studs, so there is a leak there. Will that affect them? Is it possible to get a good tune with an exhuast leak? I managed to get most of the knock out from 2500rpms up, but it still knocks at around 1000-2000 at barley any throttle. How can I tell if the 02 sensor is bad?

 

[91BlackLaser]

I just did a quick pull, but I do not know how to post it. At 5156rpms WOT INJD is 25%, knock is at 2, o2-R is a 0.48 and tps is 60.5%. All the trims are still at 100%. MAFS is 1273Hz. I know is not much to go on, but do you think the 02 sensor is bad? Oh and the car seems to want to stall when coming to a stop. I do not see any black smoke could it be a lack of fuel at idle?

 

[beatshack]

If your information really is WOT, you probably have a bad o2 sensor. 0.42v at WOT should read closer to 0.80v. Another problem with your pull is, at WOT your TPS should read over 90%, and your injector duty should be a lot higher than 25%. Are you sure that information is WOT? It sounds more like in-between shift information.