123quattro

Are you using a rising rate FPR? Maybe the vacuum reference got disconnected?

Tampa 928s

I'll check that seems like its not getting enough fuel.

Tampa 928s

Looks like its hooked up correctly.

Tampa 928s

This is a snap shot.

Jim R.

What is the A/F at idle and cruise?

Is there a throttle position/WOT switch like on the S4+, if so it may not be hitting the WOT maps and running lean.

What is the fuel pressure at idle and with vacuum disconnected? Any way to log fuel pressure while driving on and off boost? I'm using an innovate electric sender feeding the LMA-3 datalogger.

Have you pulled any spark plugs to verify the lean condition?

A free air calibration of the WBO2 may be needed, if you have the innovate stuff.

Sorry about more questions than answers, but at least that stuff is pretty easy to check. That is some serious lean under boost, be carefull.

Jim

Tampa 928s

It ran fine before I relocated the Maf back from under the fender to original location.
This is an Lh so it has a Wot switch, the low octane wire is connected to reduce timing 3 degrees.
I can look at pressure while driving I have a long hose that can rest on the wipers. I have not got that far yet.
Have not looked at the plugs and the Inovate has been calibrated.

Tampa 928s

One thought:
It also looks like the Maf voltage is low but I need to read my notes. This Maf is adjustable, these readings maybe due to the increased air flow due to the 4" intake pipe. I need to find out how to test for an idle voltage with the data logger so I can adjust the Maf.

Jim R.

Well, that changes things a bit. How low is low? I don't know how to adjust your adjustable MAF back to stock, but I'd start with that. Always easier to troubleshoot with a known baseline. I have a spare '87+ maf on the bench, if you need to borrow it let me know. It worked fine on my car while I had my other one rebuilt.

Jim

John Speake

At idle, a stock MAF reads about 2.7v.

Tampa 928s

If you look at my Jan 09 Data Sheet the Maf voltage and In duty cycle is low I belive it is poportional. In either case my Injectors are not going full cycle as before.

Steady Run
A/F Rpm Maf V Inj Boost

14.47 3158 3.33 15.2 -6.9
14.39 3158 3.28 15.2 -6.94
14.52 3158 3.29 14.8 -6.98

Under Boost:
Before Maf move as base line:
10.66 5349 5.65 98.4 3.79
10.79 5399 5.74 98.6 3.79
10.82 5439 5.69 98.7 3.75

After Maf move Jan 17 09 log
17.88 6257 3.68 42.4 2.72
18.05 6213 3.72 33.3 1.6

I am assuming per an old John Speak post chime in if I'm wrong I can place my meter on Pin 7 and pin 5 of the Lh and at idle I should adjust to 2.7 Volts

Tampa 928s

Any feed back on this?

After change of Maf and check out. Looks a little better but not rich enough!

LM1_O2 rpm MAF INJECTOR BOOST

14.73 3210 4.55 53.7 1.77 0.671
15.2 3320 4.68 53.3 2.28 0.671
15.48 3420 4.65 53.2 2.63 0.651
15.6 3530 4.72 54.3 2.93 0.635
15.39 3650 4.79 56.1 3.23 0.639
15.44 3770 4.76 57.9 3.49 0.631
15.3 3870 4.84 60.1 3.71 0.647
15.36 4000 4.88 62.3 3.88 0.651
15.55 4110 4.9 64.2 4.05 0.663
15.47 4230 4.9 66.6 4.22 0.663
15.51 4330 4.98 68.1 4.4 0.651
14.91 4450 5 71.2 4.57 0.635
14.39 4590 4.99 74.3 4.79 0.643
14.54 4730 5.04 75.9 4.96 0.651
12.77 4850 5.14 80.6 5.17 0.659
13.16 4990 5.22 84 5.35 0.671
12.23 5140 5.11 84.7 5.52 0.655
13.1 5299 5.07 83.8 5.6 0.663
13.88 5459 5.03 85.2 5.82 0.659
14.26 5609 5.19 84.8 5.95 0.647
14.27 5759 5.26 85.5 6.16 0.635
14.35 5869 5.26 87.6 6.42 0.624
13.6 6009 5.22 89.7 6.72 0.647
13.89 6129 4.46 89.9 6.85 0.573

toofast928

Can you also log fuel pressure? That's what's missing from the data stream.
Careful Tampa, running lean. I wouldn't drive the car until this is resolved. You are using a rising rate fuel regulator------right?

Jim R.

I'd be looking at fuel pressures and checking the WOT/throttle switch. If the WOT switch is not working to trigger the WOT fuel maps, it will look lean like that.



Jim

Tampa 928s

Murf sent me a smaller sized pulley and a Ezk chip. I think that the Fmu is not keeping up, I only ran 5 Lbs of boost now it's up to 7. I am not sure what diaphragm is in the Fmu but that can be changed. I was told that I should go with 36 Lb Injectors ditch the Fmu and shark tune it. Due to the cooling issues I am having in Florida with my air on I think that an inter-cooler is required. So I am going to put the larger pulley back on and see what happens. Once this lousy economy picks up I will get a kit together.

Jim R.

Looking at those logs, at similar RPM's, the A/F, MAF voltage, and injector duty cycle are way different.

At around 5400 rpm's:

When you were in the high 10's before for A/F's (rich but good and safe), the MAf v. was 5.65v to 5.74v.
You show much lower now in the 5.03v to 5.07v. range in the MAF with A/F's in the mid 13's at the same rpm's.

Injector duty cycle has dropped from ~98% before down to about ~84% after.

Were the before data logs with the larger pulley or the smaller one on there now?

Is the chipset in the computers the same for both sets of datalogs?

For some reason, your MAF is not showing the computer as much air as before, and the computer is not maxing out the injector duty cycle at WOT like before. I would focus on why those parameters have changed. I would still try to check out fuel pressure at idle, cruise and under boost just to have that information in hand and rule out the RRFPR.

Jim