PDA

View Full Version : LTFT's way off


minytrker
December 8th, 2006, 01:03 PM
I tuned a H/C vette a couple months ago and it ran perfect. The guy called today and said his car was running weird, so I went and looked at it. His LTFT's were 18% on bank 1 and 16% bank 2. What could have made the LTFT's go so far out of wack all of a sudden? I checked the O2's and they seemed to be working fine.
Whippled 496
December 8th, 2006, 05:13 PM
check for leaks in the intake tube between the MAF and manifold. Sounds like some air is getting in after the MAF sensor.
minytrker
December 9th, 2006, 02:13 AM
Checked for that and didnt see or hear any leaks.
TAQuickness
December 9th, 2006, 07:21 AM
what's your method of leak checking?
minytrker
December 9th, 2006, 07:50 AM
Sprayed brake cleaner on the on all the connections with the car running.
SSpdDmon
December 9th, 2006, 09:38 AM
Injector(s) going bad?
minytrker
December 9th, 2006, 11:29 PM
I dont think thats it, its a 30,000 mile vette. Im sure its possible but I dont think thats it.
ringram
December 10th, 2006, 12:09 AM
Misfires?
Dodgy leads, plugs etc?
TAQuickness
December 10th, 2006, 12:44 AM
Got a fast90 on it by chance?
minytrker
December 10th, 2006, 08:41 AM
New plugs and wires. The car runs fine till the fuel trims get way out of wack. It has stock TB and intake installed. The weird part is I re-tuned the car from scratch because with the previous tune in the car it wouldnt idle or startup very well at all. It drove around fine, just didnt idle or start. So I retuned it from stock and it ran and drove fine for a few weeks till the fuel trim problem.