Yamaha 150 hdpi

[Mick.Roe]

Hi, is there any experts out there on the above motors ? I could do with some advise. Thanks I’m advance

[jwalker]

Depends what you need to know, I've got two of them on my boat. Fire away, if can help, I will.

You'll likely get others along soon too.

[Mick.Roe]

Originally Posted by jwalker

Depends what you need to know, I've got two of them on my boat. Fire away, if can help, I will.



You'll likely get others along soon too.

Hi thanks for replying, i have a bit of an odd fault, originally the motor would start up and idle as it should but increase the throttle either in gear or with the lever the engine would go to maximum revs and not stop until turned off at the key. I took it to a local marine mechanic who thought it would be the TPS so that was replaced this has stopped the over revs as it now won’t idle, it fires for 2-3 seconds then dies. All the filters, seals and diaphragms have been replaced along with high pressure filter and water separator.
If I unplug the TPS the engine will idle/rev as it should, TPS is with tolerance as it the fuel sensor.
What I have noticed though is the resistance on the TPS is stable with the ignition off but with it on it increases to around 3Mega ohms and fluctuates.
I’m waiting on the YDS software, but when the mechanic plugged it in there was no faults and everything seemed correct.

[jeffstevens763@g]

My 25 Suzuki wouldn’t idle I had to pump the bulb then whip it into gear open her up and it would run at high revs all day soon as it idled again it stalled long story it had water globules in the IAK valve mechanic blew it out with compressed air no problem since. I did have a fuel separator in the line so no idea where the water came from.

Just a thought

[jwalker]

Originally Posted by Mick.Roe

Hi thanks for replying, i have a bit of an odd fault, originally the motor would start up and idle as it should but increase the throttle either in gear or with the lever the engine would go to maximum revs and not stop until turned off at the key. I took it to a local marine mechanic who thought it would be the TPS so that was replaced this has stopped the over revs as it now won’t idle, it fires for 2-3 seconds then dies. All the filters, seals and diaphragms have been replaced along with high pressure filter and water separator.
If I unplug the TPS the engine will idle/rev as it should, TPS is with tolerance as it the fuel sensor.
What I have noticed though is the resistance on the TPS is stable with the ignition off but with it on it increases to around 3Mega ohms and fluctuates.
I’m waiting on the YDS software, but when the mechanic plugged it in there was no faults and everything seemed correct.

It sounds a bit of a puzzler. I don't know enough about the throttle position sensor and how it interfaces with rest of the engine to be of help to you. However, the starting and running for the first couple of seconds is a separate routine for startup, it fires up on all 6 cylinders before dropping back to idle on 4 cylinders.

The person who may be of help to you on Ribnet is Davie, I've not seen him post for a while but it may be worth dropping him a PM.

[Jon Tallis]

I agree with JWalker, that a bit of a puzzler. Normally a fault like that would point straight at fuel but the fact that it runs OK with the TPS unplugged is curious.
When your mechanic fitted the new TPS, did he go through the link & Sync procedure as per the factory manual? It's pretty crucial to get right.
I'd suggest plugging it up to YDS, checking all the sensor ranges at Ignition off (especially the TPS range from closed to wide open), then starting and running the engine with the TPS disconnected, then connected, both times with the YDS data logger running. I cant remember how many parameters it will log but you'd definitely want RPM, throttle position, TPS voltage, ignition timing, MP fuel pressure, HP fuel pressure, battery voltage & injector pulsewidth. The log files might point you at something?
As you're finding out, the HPDI whilst a weapon when it's running right is fiendishly complicated, they were rare in the UK and there are very few people left over here who truly understand how they work.
As for extra help, as well as the guy JWalker suggested, you could try BHG in Lymington (they imported the original HPDIs but their original HPDI man has left), or MSM UK - Gavin knows his stuff and used to work for Yamaha. http://msukmarine.com/home.html
Most of the deep expertise on HPDIs now resides in the states so you could also try posting on The Hull Truth or on the HPDI group on Facebook.
Happy to help further....

[Mick.Roe]

Originally Posted by Jon Tallis

I agree with JWalker, that a bit of a puzzler. Normally a fault like that would point straight at fuel but the fact that it runs OK with the TPS unplugged is curious.
When your mechanic fitted the new TPS, did he go through the link & Sync procedure as per the factory manual? It's pretty crucial to get right.
I'd suggest plugging it up to YDS, checking all the sensor ranges at Ignition off (especially the TPS range from closed to wide open), then starting and running the engine with the TPS disconnected, then connected, both times with the YDS data logger running. I cant remember how many parameters it will log but you'd definitely want RPM, throttle position, TPS voltage, ignition timing, MP fuel pressure, HP fuel pressure, battery voltage & injector pulsewidth. The log files might point you at something?
As you're finding out, the HPDI whilst a weapon when it's running right is fiendishly complicated, they were rare in the UK and there are very few people left over here who truly understand how they work.
As for extra help, as well as the guy JWalker suggested, you could try BHG in Lymington (they imported the original HPDIs but their original HPDI man has left), or MSM UK - Gavin knows his stuff and used to work for Yamaha. http://msukmarine.com/home.html
Most of the deep expertise on HPDIs now resides in the states so you could also try posting on The Hull Truth or on the HPDI group on Facebook.
Happy to help further....

Thank you for you advise and help, once I have the software, I’ll try to see if it throws anything up, I have tested the sensors with a multimeter and test leads and all falls within tolerances.

[Jon Tallis]

Let us know how you get on. My post above should have said "ignition on, engine stationary" as first test, not ingition off