Sierra3
Registered
Car runs 2500 RPM at 70MPH with overdrive on. If you leave overdrive on and just coast brakes to a stop light, it hunts up and down for an idle. It finally just tries to find its own idle and then keeps lowering it gradually untill it stalls out at light shaking. It happens when comming down from 45 or higher and coasting with foot off the gas for more than 10 seconds (the idle doesnt know where its supposed to be it feels). It will surge from 1000RPM to about 1200 RPM and RPM needle will slowly go up and down between those ranges. It feels like its running out of gas like its getting little pockets of air in fuel line in equally spaced times. gas, stall, gas, stall, and so on. This is driving me crazy as we can't find the problem. It was doing this before the car went to dyno and after it came out. I thought for sure something was wrong with old tranny causing this, but it's not the case now. Now with the new tranny in its doing it again exactly. Car has a Walbro 255 in tank pump by the way. EEC is running with custom flashed SCT chip set for the old 1200 stock convertor. Car has 2001 SVT Cobra motor in it and running stock Mark VIII fuel system, and plugs and wires. No coil on plugs like the Stang had.
Have to get the SCT reflashed to new tranny. Art Carr Extreme is great by the way with the 3200 stall. (i actually wish i went with the 3500 stall now)
We are going to have to spread out the RPMs on the shift points though I see already from the other tranny configuration in the chip.
The only thing that is worring me about it is it clunks HARD when it down shifts from OD to 1st gear at stop lightsgetting ready to go again. You can hear and Feel it in the seat. This doesnt bother me much and i will live with it, as long as its NOT doing damage to tranny and it's normal. Any one else with ART carr trannys experience this? I won't be driving the car till i get it up to JMS racing to get another dynotune and set right as we just replaced both CATS to 2" ID ones. The other ones in my old pic were all black carbon soot and melted inside. When we started the car up after new tranny install, it blew black chunks of crystallized convertor material out of left side tailpipe. Sorry so long, but ive got some issues to work out before car gets run hard.
1995 DK Blue Lincoln Mark VIII
1998 DK Blue Chevrolet 1500 P/U
2004 BLACK/Silver HONDA CBR 600RR
Have to get the SCT reflashed to new tranny. Art Carr Extreme is great by the way with the 3200 stall. (i actually wish i went with the 3500 stall now)
We are going to have to spread out the RPMs on the shift points though I see already from the other tranny configuration in the chip. The only thing that is worring me about it is it clunks HARD when it down shifts from OD to 1st gear at stop lightsgetting ready to go again. You can hear and Feel it in the seat. This doesnt bother me much and i will live with it, as long as its NOT doing damage to tranny and it's normal. Any one else with ART carr trannys experience this? I won't be driving the car till i get it up to JMS racing to get another dynotune and set right as we just replaced both CATS to 2" ID ones. The other ones in my old pic were all black carbon soot and melted inside. When we started the car up after new tranny install, it blew black chunks of crystallized convertor material out of left side tailpipe. Sorry so long, but ive got some issues to work out before car gets run hard.
1995 DK Blue Lincoln Mark VIII
1998 DK Blue Chevrolet 1500 P/U
2004 BLACK/Silver HONDA CBR 600RR
