I have been working to tune a 1985 T-Type Buick for about 6 months now. It was a DIY hack job that I have tried to assist on. The issue has been from my first experience with it that an even acceleration or even a more aggressive acceleration will yield decent pull up to speed. When at WOT, the wideband goes to 7 and the engine will bog and eventually die. Just too much fuel. I am using tunercat to tune.
There have been some mods along the way to try and remedy this. We installed a 1987 Grand National ECU. Same exact result. We tried larger #40 injectors, #30 injectors and now they are #28 injectors. The fuel pressure regulator has been changed to the adjustable type and changed from #25 pressure to #45 pressure, same result. The vehicle has a huge 4" intake. We installed a 90mm MAF with MAF translator. When the MAF counts are trimmed to allow acceleration, after WOT, the acceleration the vehicle is dangerously lean. When the MAF is set to run at stoich, then it bogs at WOT. It acts like when you have a dashpot set way too rich on a carburetor. In looking through the tables I am just not finding anything that I am adjusting that improves the situation enough to fix the problem. I am hoping someone out there has seen this and can give some pointers on what would get this beast dialed in. With the #40 injectors, I thought maybe the Flash was not capable of trimming enough for the large injectors. But with the #28 injectors I am getting the same result. Too many hands have been on this car. It has gone from victim to victim spending tons of money on parts. I want to win on this one but I am just stumped.
BTW, I was told the CAM signal is very critical on this vehicle. I have scoped the signal under idle and WOT and it is a rock solid square wave at all times.
Reply With Quote
Originally Posted by dave w
Bookmarks