I have been using both TP4 and Datamaster for logging on a 165 ECM which has both 160 & 8192 baud, my cable is the AKM unit. TP4 logs fine but Datamaster will drop out after about 30 secs and not reconnect. Datamaster requests that 89 and earlier Camaro-Vette ECMs should wire the interface cable to short Data pins M & E...I will try this but I'm somewhat concerned that this may be a problem for TP4 logging or upset the ECM. Can someone confirm if this jumper is needed when logging with Datamaster on the 89 and earlier ECM?

IIRC pins E & M should already be connected together. If one or the other is open that can be a problem.

RBob.

RBob...thanks for comment,
yes on my 165 ecm data pins E & M are common. The problem of lost ALDL connection using Datamaster...is this uncommon?
I searched the form and found little previous threads on this subject.
Tunerpro does not have or seem to require adjustment for comms port timing as is the case with Datamaster. The Datamaster manual suggests using a trial-error method using the the comms port advanced adjustments to tune the port transfer. Can anyone recommend settings based on experience...?