In Gear RPM: How to Fix
How do I adjust my in gear RPM on a Yamaha hpdi 250? My tps is set at 0.62volts and idles around 600-700rpms in neutral, throttle body plates are sync and I get WOT with hot foot pressed. When I put it in gear the idle drops to 400-500 and it acts like it wants to die, unless I give it gas via hotfoot.it just doesn't seem normal to me. It actually sounds smoother in neutral than I gear unless I press the hotfoot some Any suggestions?
Last edited by fishnhunt; 01-24-2017 at 01:13 PM.
2007 Skeeter 20i class, Yamaha HPDI 250 "If the boat does not rock on your hookset, you are not setting it HARD ENOUGH!!" **Common sense is not common, it is a function of experience and training**
Do a sync and link set up procedure.
There is an indle adjustment screw on throttle linkage. Some will say not to mess with it but isn't that what its for, when motor idles too low? Spark plugs look normal?
Adjust your idle speed at your hot foot. You should be around 750 to 950 ish out of gear. 650 to 750 ish in gear..this is off the top of my head.
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Ok so I went and did everything I could and still have a low idle in neutral idle in gear. I link and sync the throttle plates - were fine from beginning, tps is set at 0.62 volts, new plugs, all filters were changed about 5 hrs ago on motor, and check fuel pumps for leaks and are good to go. The funny thing is that it runs like a scalded dog at wot I can turn 5700-5800 rpms and she is powerful in the mid throttle. It just will not idle it actually died on my twice at start up.
SO what else can cause the symptoms with idle at or around 400 -500rpms even with TPS set at 0.62 volts? If I turn the idle screw up any more my TPS voltage will get out of range. Throw I out there what else could cause a low idle outside of the things I have checked? I have no more ideas???
The only other thing I can reason with, could be wrong, is it isn’t firing on one cylinder at idle but is trying to that’s why I get the surge between 400-700rpms at idle, when I put it in gear it’s the same thing, it fires intermediate , and then when I get past a certain rpm that cylinder fires without hesitation? What controls what cylinders fire on the HPDI? Maybe something needs a little fine tuning?
Last edited by fishnhunt; 01-30-2017 at 07:01 AM.
2007 Skeeter 20i class, Yamaha HPDI 250 "If the boat does not rock on your hookset, you are not setting it HARD ENOUGH!!" **Common sense is not common, it is a function of experience and training**
How do u perform the link and sync procedure...my 200 HPDI doing the same thing and would like to check link / synk..thanks
SYNCHRONIZING THE THROTTLE VALVES
If the throttle is operating properly there is NO reason to perform this adjustment. Un-necessary tampering usually just leads to performance problems. Improper throttle valve adjustment will normally lead to an unstable idle. If necessary, remove the air intake silencer assembly and visually inspect the throttle valves to make sure that they open and close at the same instants. If you can see signs that the throttle valves open unevenly, adjust the valve synchronization, as follows:
The throttle valve procedure for HPDI and 250 hp EFI Vmax models is a little more involved, not more difficult, but has a few more steps. Also, following the throttle valve adjustment on these models, unlike the other EFI motors, you should skip to Throttle Position Sensor Adjustment, and come back to Idle Speed afterwards.
- If not done already, remove the air intake silencer for access.
- Disconnect the throttle lever rod and, for the HPDI and 250 hp EFI Vmax, the oil pump rod.
- Loosen the idle adjust screw until it is no longer touching the stopper.
For all EFI models, except the 250 hp Vmax, loosen the idle adjust screw only using full turns and count the number of turns outward to help resetting the idle screw after the throttle valves have been synchronized.
- Check and make sure that all the throttle valves are now fully closed once the idle screw is off the stopper. If so, no further adjustment is necessary.
On HPDI and 250 hp EFI motors it may be necessary to loosen the No. 4 throttle valve screw before the throttle valves will be completely closed. Of course, at that point, you might as well finish the adjustment procedure.
- For EFI models, loosen the throttle valve adjusting screws for all cylinders EXCEPT No. 4. On the HPDI and 250 hp EFI Vmax, loosen ALL throttle valve adjusting screws, including the No. 4 valve screw.
Because the throttle valve screws have left-hand thread, they are loosened by turning CLOCKWISE.
- Using gentle finger pressure, hold the No. 1 throttle valve in the fully closed position, then tighten the No. 1 throttle valve adjusting screw by turning it COUNTERCLOCKWISE. Repeat this step for cylinders No. 2, 3, 5, and 6.
- For all EFI models except the 250 hp Vmax, turn the idle adjust screw back inward the same number of turns you counted when loosening it. On these models, you"ve finished the procedure.
- For the HPDI and 250 hp EFI Vmax motors finish the procedure as follows:
- Reconnect the oil pump link rod.
- Turn the idle adjust screw back inward until the No. 4 throttle valve JUST starts to open, then tighten the screw an additional 1/2-1 turns.
- Align the center of the throttle roller with the mark on the throttle cam, then tighten the No. 4 throttle adjusting screw by turning it COUNTERCLOCKWISE.
- Open and close the throttle valve 2-3 times and double-check that the center of the roller is still aligned with the mark.
- For 3.3L HPDI models, connect a 3-pin test harness to the Throttle Position Sensor (TPS) wiring harness. Then turn the ignition switch ON and check the TPS output voltage across the Pink and Orange wires of the harness using a Digital Volt Ohmmeter (DVOM). Turn the idle adjust screw in or out as necessary until the TPS output is 0.58-0.62 volts. In theory, you can skip the TPS adjustment procedure for this model since you"ve just checked/adjusted it now.
- Disconnect the throttle cable joint and adjust the lever rod to 6.2 in. (157mm) for EFI motors, 6.4 in. (163mm) for 2.5L HPDI motors or to 6.0 in. (151.5mm) for 3.3L HPDI motors. Once the length is set, reconnect the cable joint.
- Install the air intake silencer and proceed to Throttle Position Sensor Adjustment before setting the Idle Speed
On all HPDI and the 250 Hp EFI Vmax, you"ll also have to adjust the throttle lever rod length
2007 Skeeter 20i class, Yamaha HPDI 250 "If the boat does not rock on your hookset, you are not setting it HARD ENOUGH!!" **Common sense is not common, it is a function of experience and training**
It idles on four, and goes to six firing when put in gear. Controlled by a switch on the throttle linkage I think. I've been told you cannot wire around that switch, the computer somehow knows it. That never made any sense to me and I never tried myself to wire around it.
I seem to recall that the neutral switch is open when the motor is started and closed when the motor is in gear. If the switch is closed all of the time then the motor will know something is amiss since during engine start (motor is out of gear) it expects the switch to be open. And it is not. The ECU may set a code and default to fixed timing/fuel map.Originally Posted by Charlie206
If that's the case you could run a toggle to the dash.
I had a similar situation a while back and my main problem was the neutral switch was out of adjustment once we got that figured out the idle still jumped around all summer even after several link and synks. Changed out the TPS and all is fine now.
On the HPDI the TPS should be set at .48-.52 volts with throttle plates closed then with idle stop screw adjust to .58-.62.
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