I am tuning a '91 Legacy T with auto tranny and am experiencing what I think is ignition cut out when the car shifts from 1st to 2nd on a hard run. I don't think that it is fuel cut because I dump a cloud of unburnt (black) fuel during the cut out time. NOTE: This cut out time is .5 seconds max and then it's on to 2nd gear and the rest of the 1/4 mile run
I am using a tried and true fuel cut defender and plus it will even happen on 10 psi of boost - NOTE: Never below that boost. I am using new NGK V-Groove plugs and nice NGK Wires.
TDO5-16g small, '02 WRX TMIC with water spray, Bell mouth with 3" Mandrel exhaust - no cats, Greddy Profec A @ rock solid 14psi.
My plugs are gapped about at about for higher boost about 30 but I'll check them out. One thing to note: My O2 sensor is not working in its current position - just before the second cat. Maybe this has something to do with it.
Changed my coil pack last night and it didn't take the problem away...
My plugs are gapped about at about for higher boost about 30 but I'll check them out. One thing to note: My O2 sensor is not working in its current position - just before the second cat. Maybe this has something to do with it.
Changed my coil pack last night and it didn't take the problem away...
The O2 sensor is already disconnected from the ecu and system has reset. Any other ideas? tried a few more 1/4 mile runs last night but my times sure suffer with this cutout from first to second. I did notice on the graphs from my runs that the 1st to second shifts around 6600 rpm and the next shift is around 6100 rpm. Maybe I should buy a set of colder plugs and gap them smaller.
Other ideas??
BTW: my tranny is suffering the torque bind and I have another 4eat 4.11 tranny from a newer Leagacy Wagon to drop in. Swapped over the LSD clutches from the 3.90 stock rear and that gear reduction should drop the times down. Total gear reduction from stock including my 195/45/15 tires and this new tranny is over 13%. Got to get into the 12's : )
Thanks for sticking with me! Yes - only at full boost on the 1st to 2nd shift. The only difference I can see with this shift is the rpms are around 6600 which is a little higher than the others at 6100.
No problem . Hmm... I wonder if you're hitting the rev limiter (isn't it supposed to kick in at around 6500 RPM?) because your engine is accelerating so fast that the TCU can't keep up with it. I remember Dave saying he experienced the same phenomenon after he installed his MSD ignition. I don't know why that would cause a cloud of black smoke, though.
"Just reading vrg3's convoluted, information-packed posts made me feel better all over again." -- subyluvr2212
I didn't know there was a rev limiter on these cars. Makes good sense that my problem is because of it! I have modded 2 other Legacy T's with auto trannies and never had a problem with the limiter. In fact, by varying the amount of fluid, we could get the tranny to shift at 7500 rpm (removed fluid). Anyway, last night I ensured my fluid was up and I did have to add a little. The car still has the asame problem and I can watch the revs climb past 6500 and the same problem occurs.
I could swap ECU's with the car we would run to 7500 but I'm wondering if the is another problem with the way these sensors and control units signal each other.?.?.
I added a fifth injector last nightjust upstream of the throttle plate. It is a small 19lb injector but I'm hoping for a little 'insurance' when I run a couple more psi.
Maybe the transmission just isn't shifting fast enough. Do you know if all the clutches and brake bands and whatnot are in good shape? Is the fluid good and clean?
"Just reading vrg3's convoluted, information-packed posts made me feel better all over again." -- subyluvr2212
Problem solved The fluid level was still too low tonight and I added a whole lot to it! I was not reading the stick properly or something and thought I had enough in there yesterday and on previous checks. Now the car shifts properly or right at 6500 with no cut out. Tomorrow I'll do some Gtech runs and let you know how it does without the cut out mid shift. Hoping for 13.5 or better in the 1/4. Thanks to all of you who responded to this post. I am a little embarrassed
