2002 Mercury 225 Optimax TPS Testing

Bigstix4fish

Recruit
Joined
Sep 21, 2017
Messages
1
Hello! I have a 2002 Mercury 225 Optimax. Own the boat for 3 years now. I can not get it to start with out advancing the throttle. I understand that's a big NO NO. The Motor runs great doesn't skip a beat. Sometimes at idle switching in FWD and REV while docking it will STALL.

TPS Mercury part # 832952-11

So I look at the book an the specs for the TPS state @ Idle voltage should read .4 - 1.3 vdc and @ WOT 4.0 - 4.7 vdc

I tested the TPS sensor with a Digtal meter.
@ Idle .11 vdc
@ WOT 4.71 vdc

When I advance the throttle to get it started it is very lightly. I look to see if the cam opens the throttle body at all and it does not.

I read voltage at the TPS with the throttle advanced it was reading 1.1 vdc starts up right away. I took the linkage off the TPS and used a wiretie to hold the TPS sensor at 1.1 vdc. Motor started up right away.

To get the TPS sensor to read 1.1 vdc has to be moved atleast a 1/4" to get that voltage reading.

I tried to start it with the TPS advance to .4 vdc and it will not start (very close tho). That's the lowest vdc spec in the book for the TPS sensor.

I appreciate any info. I don't want to purchase a brand new TPS if that's not the problem. I'm leaning towards TPS.

I'm very courious of the readings on a BRAND NEW TPS.

I did read about shift and throttle cable adjustment as well. I will check that to make sure it's to specs.

Thanks again
Kevin
 
Last edited:

stikboyy

Cadet
Joined
May 3, 2012
Messages
24
Welcome aboard,
The TPS is non adjustable, if it is out of range it generally needs to be replaced. The only thing you can check is if the idle stop screw on the throttle arm has backed off and is causing the arm to move too far back. If that is good then your TPS will have to be replaced.
 
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