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I used a Merc scan tool and this is what I got...???
PORT
Engine RPM 850-1400
Coolant Temp 85
Manifold Air Temp 92
TPS Volts .50
Trottle tps 0
Map Volts .72
Manifold Pressure 7
Baro Volts 2.09
Battery Volts 14.1
Spark Advance 3.1 deg
IAC position 41
Base IAC 21
IAC follower 20
Injector on time 2.7
Fuel flow rate 5.5
2nd run for port engine
Engine RPM 1400
Coolant Temp 115
Manifold Air Temp 107
TPS Volts .50
Trottle tps 0
Map Volts .70
Manifold Pressure 6.9
Baro Volts 2.09
Battery Volts 14
Spark Advance 9.8 deg
IAC position 77
Base IAC 77
IAC follower 0
Injector on time 2.8
Fuel flow rate 7
STARBOARD
Engine RPM 830
Idle speed 837
Coolant Temp 81
Manifold Air Temp 70
TPS Volts .52
Trottle tps 0
Map Volts 1.01
Manifold Pressure 8.5
Baro Volts 2.09
Battery Volts 14.2
Spark Advance -.03 (all over the board)
IAC Position 9
Base IAC 9
IAC follower 0
Injector on time 2.4
Fuel flow rate 3.3
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IF the ECMs are easy to get to, swap them port-starboard. See if the readings are the same. That will let you know if you have a bad ECM timing controller.
If timing was all over, either ECM is being erratic or the module in the distributor are just a few possibilities.
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Hello! Look at your IAC 'counts'. Look at the IAC position. Very lightly bend the throttle linkage arm, at the 90 degree angle where it sits on the stop screw. You need to have a "little" more throttle plate opening, and let the IAC motor 'trim' the idle speed. You are "too heavy" into the IAC counts, and that makes the A/F hunt (surge). Do this 'trick' while on the DDT (motor not running) so that you will retain the TPS ZERO % count. You want air, not TPS changes! Your IAC FOLLOWER is showing 20 counts and that equals SURGE! Blower or not. Most stock motors show 3 to 5 on the counts, under normal conditions. The motor should crank and start up with 100% IAC, then quickly settle down to an area around the 20/30's (stock). You can control the 'surge' by opening or closing the throttle plates. Use the IAC to even out your idle, not all of the air the motor needs to idle. You need to open the throttle plates up! MORE AIR.
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thanks for everyones advise but I still have the same problem. I swapped the ECU, MAP, and the throttle bodies which also included the IAC and TPS from one motor to the other and I ran the starboard motor and it was perfect.
The port motor still serges.... so now what????
Signed
Looking for sharp object to bang my head on.
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The throttle cable on that motor is forcing the throttle plates closed. Put them all back to original condition, remove throttle control cables and reset port motor throttle plates, and then the cable. Rich mixture causes surge! Of course you may have a bad pressure regulator.
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The throttle cable on that motor is forcing the throttle plates closed. Put them all back to original condition, remove throttle control cables and reset port motor throttle plates, and then the cable. Rich mixture causes surge! Of course you may have a bad pressure regulator.
Question though....As I read your previous post wouldn't swapping the whole throttle body be the same thing??? I know there was pressure on the throttle plates but its on both motors. I took both throttle bodies off and adjusted the port side to match the starboard side and then swapped them. I swapped one peice at a time and then ran the motors. The starboard motor runs fine and it has all the port sensors, ECU, MAP, IAC, TPS, and trottle body, yet I still have a surge problem. I'm at a loss???
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One should always look at the simple things first....I guess.
It turns out the distributor had moved and the timing was out by a couple of degrees causing the motor to surge. Re timed motor @12' base timing and I'm dilemma free.
Thanks for everyones input it was GREATLY appreciated.
Jason