Fuel Problem COS3 E40

[Forcefedperformance]

We Are having a problem with a 06 GTO going lean for some odd reason and we are having trouble finding out why its doing it....the car is a 6.0 stock bottem end with ETP LS1 Heads,Cam,APS Twin Fuel Pump,60LB injectors,Aeromotive aeromotive regulator and a F1 A Procharger.

We was making about 5 PSI at 5800 and everything was fine so we changed the pully to make some more boost and now whenever we hit about 5000-5200 rpm no matter how high we make the boost ve numbers it will allways go lean in the same spot

Could someone please take a look the file and see if we are over looking something?

Thanks ,Bill

[Delco]

Can you post up a log showing the afr's and the injector duty cycle.

one obvious thing is the 105kpa line in the boost table is very low compared the the non boosted table - they should both be the same.

You are also tunning a lot of spark advance , a misfire will cause the wideband to read lean

[Forcefedperformance]

The spark advance is @ 17 degrees, there is no misfires & we are running 60lb. injectors which are equivelant to around 70lb. at the 60psi we are running the system at so the injectors are no where near maxing out. The fuel system is more than adequate, dual 255lph intank pumps with a seperate -6 feed line from each pump to each rail with a cross over line & regulator after the rails. We varified the fuel pressure & it is staying steady at around 60psi all the way through the run. The car is only making around 6-7psi @ 5000RPM but our fuel problem starts at around 4500RPM, 135kpa & 400 rwhp. We had the same problem with the larger pulley or less boost at 5800RPM & 135kpa & 500rwhp. This is telling me that the problem is not an injector issue because the problem seems to be following the manifold pressure (kpa value), not RPM or horse power. There is some limiting factor in the program which I can not find in the file, maybe it is not visible due to the software not showing a table or threshold setting?

[Delco]

I have used the E40 custom OS on a lot of cars , some running into 3 bar and making over 1000rwhp , never had a issue with the fueling tables.

I assume you have sucked the tune out to ensure that it did go in properly ?

17 deg is still a fair bit of timing for a boosted E40 unless you are running on good fuel , typically we see 10-11 deg out of these combos on the fuel we use here.

A log is really the next step to see what is happening

[johnv]

not sure but maybe table B2030 needs raising some.

17-18 deg timeing does seem a little high for boost unless your lower compression or useing high oct fuel or meth.

[Forcefedperformance]

the ETP Heads we are using are 72cc and we are using 105 octane

Here the the data log...one thing that we did just notice was that our APCyl was droping for some odd reason

also the wideband on that data log is not working right ....we have been going off of the wideband on our dyno. Its a Dyno Dynamics dyno

I can also post the data log from the dyno if need be

[Redline Motorsports]

the ETP Heads we are using are 72cc and we are using 105 octane

Here the the data log...one thing that we did just notice was that our APCyl was droping for some odd reason

also the wideband on that data log is not working right ....we have been going off of the wideband on our dyno. Its a Dyno Dynamics dyno

I can also post the data log from the dyno if need be

One thing to check when the Dynamic cylinder air falls off is a leak in the system. You still can have measured boost pressure and no volume. The mass air meter is measuring load which is how grams/cylinder is determined. If it is dropping off so is volume.

If you are using the standard DD wideband its a piece of crap. We ditched ours and replaced it with a Autronics System B and never looked back. I assume you are taking AFR with a bung in the exhaust?

Howard

[Forcefedperformance]

this is a SD with no maf but i will smoke the system to see if there is a leak.

The wideband for the dyno works great ...we have the LM-1 hooked up to the efilive cable and thats the one we are having problems with.

Yes we have 2 bungs in each collector

[Forcefedperformance]

Well we smoked the system ..no leaks...any thing else any one can think of?

[Doc]

For clarity, which side is the WBO2 sensor in? Or both? Have you compared the readings btw the two?