Few problems i would like help with

WHITE94COBRA said:

My BBK TB also had the little plastic bushing, make sure to put it in the right way, If its backwards I dont believe it will even go on. Our TPS's are not adjustable?? unless drilled out! And theres really no reason for that, (at least I havent figured one out yet) Mine stays perfect at .98 - .99 at Idle. Backfiring sounds like either a vaccuume leak or too much air, or maybe even too much gas. All points to vaccuume though.

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The 94-95 TPS is not adjustable, because the computer interprets the value first. I've seen some confusion over this, so lemme see if I can explain the math behind it. If you hated all the "x + y = z" questions in math class, you probably won't like this one either.

The 94-95 EEC's TPS lookup table starts at "0", "0" being the idle voltage. It then has entries for all the incremental steps past that. The EEC reads in the idle TPS value, and subtracts that value from all future readings. This gets its base value.

Example: Idle is read at 0.98 volts. EEC reads that, and considers that to be "0". You accelerate, and the TPS now reads 1.23 volts. The EEC takes 1.23, subtracts 0.98 (the base value), and comes up with .25 volts. It then looks up in the TPS table what to do with 0.25 volts.

Now, let's say you drill out the TPS and set it to 1.01 volts. You start the car, and 1.01 becomes the "0" value. You accelerate the same way you did in the previous example, and the TPS reads 1.26 volts. The EEC takes 1.26, subtracts 1.01 and comes up with .25 volts. The exact same as the previous value.

This change in the EEC means you don't have to fine-tune the TPS voltage, as in earlier years. It takes away a tuning tool, but you don't need it anymore. All you need to do is check if the TPS is reading consistent voltages along its travel. If the voltage jumps or sticks, the TPS needs to be replaced.