george 88gta

iTrader: (1)

Have something strange happening. I have my TPS set to 0.52 volts, using my scanner. Recently changed the ECM, used a rebuilt AC Delco unit. Went for a ride today and car likes to stay at 35-40 MPH. Have to lightly apply brakes to get it down to a lower speed. Base idle is set at 650 rpm. Engine has been modified, vortec heads, GM LT4 cam kit, SLP runners and 24 lb injectors. I had the prom retuned for the mods. I checked the TPS setting , using the scanner, and the reading is 0.52 volts, engine off and 0.60 volts engine running. I dont recall this type of voltage change before changing the ECM. Anyone seen this before?

formula_novice

iTrader: (1)

With the engine idling or the key forward, the TPS voltage should be consistent.
You want a minimum of 0.54 volts (the factory setting).

It sounds like something isn't right... just my 2 cents.

Hope this helps!

george 88gta

iTrader: (1)

Yesterday, I checked battery voltage ( after leaving car hooked up to a battery tender for 12 hours) and it was 12.2 volts. TPS was at 0.52. Started car , TPS jumped up to 0.56 and battery voltage was 14.4 volts. I readjusted the TPS ( engine off) to 0.50, started the car and it jumps to 0.54. So TPS is within limits, but I dont recall this happening before I replaced the ECM. When I get some time, I will check and see what the 5 volt reference voltage looks like. Since the range for the TPS is +/- 0.08 volts, I am still in the operating range, just dont recall this problem before.