Drag Race limiter problems
 

We currently run a ford 390 in our drag car. We tested last weekend putting a button on the brake petal to activate a limiter so we can leave at the same rpm every launch. we push down brake which activates switch and then put gas to floor, once the lite goes green we get off of brake and it should run like normal but it doesn't. After three tests at the track it seemed as if once the button was let go the car would bog down for a few feet and then come to life(as if it were getting too much gas or something). we were testing a launch at 2600 since that is what we usually launch at with just foot brake. the longer we would be on the limiter the longer the car would bog down. We also run a 427 with transbrake and when it leaves off of limiter it leaves hard like it always does no problems. please help with ideas why the 390 is bogging down after being on limiter then let go or if any of you have seen this problem.