won't run when put in SD without a TON of fuel...

[dlove]

ls2 with l92 heads and a mild cam

COS3

I just put a new intake setup on, the gmpp and went to retune the car for sd with the new intake.

I have done auto ve a number of times in the past with geat luck.

but this time i think i over looked something...

If i leave the tune alone (maf tune) but just turn off the mil for the maf. The car drives great.

but when i go to turn off the process enablers and fail limits. The car wants a TON more fuel. So much that i have to max out the main ve table. Like in the 400's up to 500's. It does drive like that but i know it is wrong. So I put it back to thinking the maf is there, and auto ve'ed it like that.


Is there something else I need to turn off that isnt in the auto ve guide?

[Black02SS]

Make sure the car is actually failing the MAF.

[TAQuickness]

What AFR is your WB reporting while this happens?
When the MAF is enabled, what airflow is it reporting (are you at the top of the scale)?

[dlove]

Make sure the car is actually failing the MAF.

I will check the parameters


What AFR is your WB reporting while this happens?
When the MAF is enabled, what airflow is it reporting (are you at the top of the scale)?

unless i add a ton of fuel, it max's out the wb. I even tried re setting the wb.


i will have to see what it says for the airflow

i will get the tune up later

[joecar]

Like Chad/Black02SS said, mke sure the MAF fails (should see DTC P0102 or P0103).

[Aloicious]

Like Chad/Black02SS said, mke sure the MAF fails (should see DTC P0102 or P0103).

also make sure your fuel pressure is good and you have the IFR table correctly setup

I had a simmilar problem when I swapped from CSFI to MPFI, seems my adjustable FPR was not functioning correctly and was only giving me about 20 psi where I had the IFR table set at 55psi. I didn't find that out until a few days later, but while troubleshooting I found that it would drive decently with the MAF enabled, but in SD the VE would have to be at around 400 to do much of anything. after changing the FPR, setting it up correctly, and verifying the IFR table settings, problem solved.

[dlove]

also make sure your fuel pressure is good and you have the IFR table correctly setup

I had a simmilar problem when I swapped from CSFI to MPFI, seems my adjustable FPR was not functioning correctly and was only giving me about 20 psi where I had the IFR table set at 55psi. I didn't find that out until a few days later, but while troubleshooting I found that it would drive decently with the MAF enabled, but in SD the VE would have to be at around 400 to do much of anything. after changing the FPR, setting it up correctly, and verifying the IFR table settings, problem solved.

ifr table is good. im guessing the fuel is good because when it is in maf mode but running without it, the car still runs mid 10's

[Aloicious]

ifr table is good. im guessing the fuel is good because when it is in maf mode but running without it, the car still runs mid 10's

well, its up to you, but i'd recommend checking the fuel pressure anyways, to make sure it is actually good rather than just guessing.

mine gave VERY simmilar problems as yours. granted, my engine is a very different beast than an LS2. but if you are able to rule out a physical problem with the fuel delivery, then you're much closer to finding the actual problem. and if your MAF sensor is actually failing (DTC p0102 or p0103 like stated above) meaning you're truely going into SD mode and SD is requiring THAT much fuel to run, then I'd bet that the problem is more likely something physical, rather than solely tune related. (especially since you just swapped your intake before the problem started)

I've found using the MAF can mask potential problems in other areas, like my fuel pressure issue.