(turboed) loss of power

[jahen]

Running 8psi max on 30lb inj, turbo chip on motronic, lc1 wbO2,adjustable fuel pressure reg set to 48psi when at atmospheric pressure (vac line off). adjusted afm allen screw down and set idle. Car idles perfect, 1st gear is good, 2nd is ok, but as soon as the engine gets into a load at 2500rpm it loses power significantly. My afrs are 13.4 to 14.0 when it starts to lose power (not even boosting yet) so according to the lc1 it should be ok. I'm waiting on my MS setup but i'd like to drive the car gently until I get tuned. Thanks ahead for the help. I have a feeling its my afm adjustment....not too familiar with this adjustment.

[Bothfeetin]

turbo lag?????

[jahen]

No. Its a stumble at 2500+rpm, feels like its flooding.

[E30-323ti]

No. Its a stumble at 2500+rpm, feels like its flooding.

With an AFR of 14:1 it's more like detonation as you are coming onboost.

Wind back the timing and get some fuel in there before she blows......

[LowR3V'in]

You need to put in a pressure switch to activate wot
or else at part throttle motronic will try to cut fuel back.

Try to aim for 12.5:1.

I know with mine it would make boost on the freeway part throttle.

[jahen]

With an AFR of 14:1 it's more like detonation as you are coming onboost.

Wind back the timing and get some fuel in there before she blows......

how do i do this? this sounds like my issue, im using motronic and its very glitchy. it used to run fine til i took it to a smog shop, not sure if they reset the computer and wiped out the adaptations....

[jahen]

You need to put in a pressure switch to activate wot
or else at part throttle motronic will try to cut fuel back.

Try to aim for 12.5:1.

I know with mine it would make boost on the freeway part throttle.

you have a point also, no matter how i tune the afm it still cuts me off at about atmospheric pressure and even shuts the fuel completly off on rare occasions (stalls out)

[jahen]

took it for a run today adjusting base fuel pressure to 48psi at atmospheric pressure. found same cutoff at 2500rpm approaching atmospheric pressure. tried 30 psi, same thing. 40psi, same thing. tried disconnecting the dme to reset it and same thing. i really think the dme is wigging out and performing the fuel cutoff when i hit atmospheric pressure in the manifold. only question is, how is it that it ran perfectly fine for a week straight?

[LowR3V'in]

What fuel pressure regulator are you using?
If you don't use a begi style it will be lean until it goes over atmospheric.


Install injectors.
Flog it for a day for the ecu to somewhat adapt. It will.
Only adjust afm wheel for an ok idle afr.
Adjust FPR so you get 12-12.5 over atmospheric. 13:1 is good approaching.

Thread might have some good tips

http://www.e30tech.com/forum/showthread.php?t=31469

[jahen]

I use an aeromotive adjustable reg with boost signal, 10:1 I believe. Thanks I'll try that!

[jahen]

Oh, also I've been through that thread many times and it helped my idle a while back. Just still wondering if the base fuel pressure is supposed to be as high as 45psi....

[jahen]

Just noticed my right axle has a lot of play....gonna take care of that first to rule that out

[Danny]

Your right axle will affect how your engine performs. Good idea.

[LowR3V'in]

Well if it's stumbling because you're leaning out right before boost
you won't be able to fix that unless you get a begi.

gl.

[jahen]

Thanks. I'll try to get some work done this weekend. whats the difference between the begi and a normal adjustable fpr though???