Engine stalls on acceleration

[IMSAracer944]

87, 944 Base, has been running fine, now on accelerating engine bogs down when reaches 2500-3000 rpm, change gears and good till same rpm then falls on it’s face again. Two years ago replaced fuel filter, fuel pump, coil, wires, plugs everything trying to run down an engine shut down after a couple of blocks leaving home, eventually found bad ECU due to water damage from leaking windshield seal, replaced seal and installed remanufactured ECU and all has been good for2 years. Pulled the fuel filter to check for trash but clean, installed new anyway but no change. Not sure what to check next?

[UncleRay]

Any chance a rev limiter is affecting how high it will go? There's a thread back in 2012 that asked that question. Good luck with getting it solved.

[944 Ecology]

Check your flywheel sensors with a scope. Compare the waveforms to those in the factory workshop manual.

[nize]

that's right around when the turbo boost kicks in, possibly a KLR issue? have you checked the blink codes?

[944 Ecology]

Originally Posted by nize

that's right around when the turbo boost kicks in, possibly a KLR issue? have you checked the blink codes?

Not a turbo, according to first post in the thread.

[IMSAracer944]

Originally Posted by 944 Ecology

Check your flywheel sensors with a scope. Compare the waveforms to those in the factory workshop manual.

Not sure where to get access to a scope, but did replace the speed and reference sensors about 6-8 months ago. So far checked for vacuum leak at fuel regulator, disconnected the oxygen sensor and wiggled the wiring going to the throttle position switch, no difference. I did see where the insulation is broken on the wiring on the sensor plug on the harness side, was going to try to insulate with electrical tape to see if that it but I thought the sensors were just to start the engine. Do they give constant information to the ECM for acceleration?

[944 Ecology]

Originally Posted by IMSAracer944

Do they give constant information to the ECM for acceleration?

The flywheels sensors continually provide engine rpm and TDC info to the ECM as input to ignition timing and fuel injection. If the speed sensor is not adjusted properly or are malfunctioning, the waveform will not be what the ECM is looking for and will "confuse" the ECM. If you have a scope or access to one, you should be able to rule out the sensors, or see that they have a problem.

[nize]

Originally Posted by 944 Ecology

Not a turbo, according to first post in the thread.

hah. why is this posted in the turbo forum? moving it to the n/a forum...

[walfreyydo]

Check and if needed, repair the AFM (outlined in Clarks Garage)
Check for Vacuum leaks (does the engine stall when revved while stationary? If so, vacuum leak).