MoTeC Global Forum

Any one running these on M48? I'm having an issue with one failing flow check after limited use hours. Aircooled 911.

Current setup:
IJCU = 0.0 setup indicates 12 and 16 ohm set to 0.0
IJbc = -1 user defined table below
IJOP = 0 for sequential

battery comp table
V usec
---- -----
5 2500
6 2500
7 2500
8 2120
9 1640
10 1340
11 1100
12 940
13 800
14 680
15 580

Any other setup parameters I'm missing or corrections to these?

Did you test these on a flow bench?

Usually the reason for an injector losing flow compared to other matching injectors is a blockage in the internals of the injectors.

...Have more data here.

I implemented individual cylinder head temperatures on my 911 race motor using thermocouples in factory location on head. Cyl #3 stock sensor, balance of heads thermo couples. I checked TC's against factory sensor on hot plate in block of aluminum and temps were close (within ~10F-15F or so) up to around 350F.

When I run the motor (noticed on cam run in and recent trip to dyno), cylinder #4 is about 60F cooler than the other heads. Other heads within about 20F.

Previously had injector 4 fail after a few hours. Had all Injectors flow checked and cleaned, this inj failed flow check and did not correct itself after cleaning. Replaced with new inj, then after cam run in, put another new inj in. Sent #4 off to be flow checked again.

I had previously noticed #4 looking richer based on plug reading. ...I thought I had leaky valve stem seal on intake. Changed the seal before I added TC's to motor.

Looked at inj waveforms 4,5,6 on oscilliscope using inj test in diagnostics (pics below). All look the same. Inj are wired correct, looking at inj plug +12V on left.

Thoughts? ...could injector driver be failing when motor running? ...how can i check it?