distributors on 7.4 MerCruiser engines 1997 seems to be an issue Replace distributors on both engines
I have replaced two distributors with on two different engines within two months is any one having any problems with them.
I think you got the explanation wrong, that's not how it works. But, whatever other info you have, post it
My explanation is correct, electronically the distributor is not allowing gas to flow to ejectors . Mechanic said he has replaced four this season.
you may need to replace the IC module, not the dist. TH module supplies the pulse to the ecm to send fuel to the injectors and operate them
DISTRIBUTOR REFERENCE (DIST REF) GM refers to this as Ignition Control (IC). The distributor reference (engine speed signal) is supplied to the ECM by way of the “Dist Ref Hi” line from the High Energy Ignition (HEI). This pulse counter type input creates the timing signal for the pulsing of the fuel injectors, as well as the Ignition Control (IC) functions. This signal is used for a number of control and testing functions within the ECM.
MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 Page 5B-26 90-861326--1 MARCH 1999 The ECM controls the primary current going to the ignition coil. It sends a voltage signal to the IC module that sends a voltage signal to the ignition coil. This signal will trigger the coil creating secondary spark to be produced. The secondary spark is sent to the distributor and then to the correct cylinder by high tension leads. The Ignition Control (IC) module maintains the base ignition timing. It also has a 27-degree spark advance built into it in case there is a Code for an IC operation failure detected while the engine is running. The engine will continue to run but at reduced performance. J1-10 J2-10 J1-24 76082 ECM A B J1-20 J1-4 J1-5 450 BLK B A B A J1-3 902 RED 423 WHT 121 WHT 424 TAN/BLK 430 PUR/WHT 453 RED/BLK BRN PNK 450 BLK 450 BLK BLK = BLACK BLU = BLUE BRN = BROWN GRY = GRAY GRN = GREEN ORN = ORANGE PNK = PINK PUR = PURPLE RED = RED TAN = TAN WHT = WHITE YEL = YELLOW LIT = LIGHT DRK = DARK a b c d e f g h i k j l m n o Typical System Shown a - ECM Ground b - ECM Ground c - ECM Ground d - Ignition Control e - Distributor Reference HIGH f - Bypass g - Distributor Reference LOW h - To Tachometer i - 2-Way Black Connector j - 2-Way Gray Connector k - From Ignition Relay l - 2-Way Coil Jumper Harness m - IC Module n - 8 Cylinder Distributor o - Pick-up Coi
