Hi, I'm new to the forum.
I have a problem I haven't been able to find a solution for.
94 GM TBI 7.4 Truck. 395 ECU BHDF Moates G1 adapter, Tunerpro RT.
I can rev up moderately just fine, but if I WOT from idle, it instantly reads 6375 RPM and 23000 degrees spark advance.
(about 1200 RPM by the external tach) It then backfires through the throttle body.
It does this with the stock $OE bin, I also tried a stock $OD bin with the same results.
This is in Open loop, map reading of 80, TPS 2.1 volts.
I replaced cap/rotor/wires to rule out secondary ignition misfire, but this seems more of a computer issue.
Could I have a bad ECU?
Could I have a bad Memcal?
other unrelated issues:
ECU reads the O2 constant 446mv, but I measure varying .90-.93v at the pin.
On hot restart, it struggles against the timing. Even though it's reading 0 degrees advanced.
If I reset the ECU by disconnecting the battery, it starts up with ease.
Has anyone seen this before?