If someone could look at this file and point me in a direction. I have replaced the O2 sensors and checked for every possible leak and found nothing. The car runs like complete **it.

It is running on a custom tune by Bryan Herter and ran fine last fall.

Thanks in advance for any help.


How do I post the Datamaster file?

Thanks again

 

I reprogrammed the car with tunercat and brought the injector flow rate down from 26.58 to 18.54 and the car starts and runs. The left side blm short and long is dead on at 128. The right side is at 134 short and 160 long. I was mistaken in that the car is running extremely lean and burns your eyes badly. It is alot better now but still there.

Any ideas to what might be causing this?

Thanks again

 

You have to upload your file to an ftp site, then post the address.

 

Does the car run fine for the first few minutes when you crank it up then go to crap after it goes into closed loop?

What sort of Intake system from the TB to any porting do you have done?

What size cam are you running?

Have you confirmed your IAC position is correct?

Be sure you have good fuel pressure and are getting good spark to all cylinders(no burned/arcing wires or fouled spark plugs) or anything we may recommend will be a shot in the dark.

 

4 bolt
383ci block with forged pistons, connecting rods and forged 3.75 crank
222/232 @ .050
.510 intake/.540 exhaust
114 lobe center
10.5 to 1 compression ratio
Aluminum GM cylinder heads with 2.02/1.60 valves
130 lbs. springs w GM roller tip rockers
Heads are 180cc -225intake/186exhaust port sizes

Car has 255 fuel pump and stock fpr with 26lb injectors

tb is BBK 52mm

intake is a stock LT1

When I change the inj flow rate down alot on tunercat the car idle gets alot better and the motor becomes more responsive.

http://www.mediafire.com/file/z3m0zafmtlm/z run idle.uni

 

What you did with the injector constant was entirely incorrect, the car is adding as much fuel as it possibly can and it is so lean in open loop even with that additional fuel that it will barely idle.

Are you lightly blipping the gas when the car is cold to keep it running in this log?

You need to open the cars tb blades up just a little to let it get some more air so it can idle properly, when you first start the car it is really struggling to stay running due to being lean and the idle air controller motor being maxed out wide open when the car is in open loop.

You have alot of spark retard at various places, and toward the end of your log both of your o2 sensors pretty much die for whatever reason and go dead lean despite the extra fuel being added and the car goes back into open loop. You can see it throw a dtc and then both of them start hanging around 0V.

Are you running open headers with this car?

Everything otherwise looks ok besides your injector constant being way out in left field. Perhaps a lack of timing at idle but who can tell with all the knock retard that is present.