4 stroke 2005 90hp chugging

[rdlone]

Engine will not go over 2400rpm without chugging and reducing rpm. Starts and idles great and no codes. Started with making oil problem and gone through 3 lift pumps (expensive) and have now eliminated that problem with electric lift pump.
spent over 2 grand on 2 different mechanics and problem still around. Ughhhhh
guessing next step check hp fuel pressure then pull apart intake and injectors.

 

[racerone]

Suzuki / Johnson ??----Did you check the SHIFT SWITCH on the motor linkages.-----If it tells the module that it is in neutral the motor will not rev up when in gear.

 

[rdlone]

Johnson; switch ok. Increases up 2400 rpm if go up nice and slow but any further movement, it starts chugging. Looks like timing is advancing about 10 degrees up to that 2400 point.

 

[jakedaawg]

If you just turn the key 1 position clockwise do you get a beep and the lights on the system check guage light and then go out?

 

[jakedaawg]

Johnson; switch ok. Increases up 2400 rpm if go up nice and slow but any further movement, it starts chugging. Looks like timing is advancing about 10 degrees up to that 2400 point.

How did you verify the neutral switch? Do you have the software to read what the emm sees?

 

[racerone]

I am quite sure this is a SUZUKI built motor !!

 

[82rude]

Rebadged Suzuki.

 

[jakedaawg]

I think everyone knows it's a rebadged suzuki, that doesn't change the info and tips he can gain here....

 

[rdlone]

The way I read it ,Shift switch/ neutral switch only shows as being on or off and engine will not start if out of position. We talking about same switch?
yes, turning key on lights go through test then out. Showing no codes.
sorry about slow replys but have limited Internet where I live.

 

[racerone]

2 different switches.

 

[jakedaawg]

Just going to clarify a little bit...

The neutral safety switch in the remote control is the start in gear protection.

The switch that may be giving you an issue is on the shift linkage at the motor. It tells the computer if the engine is in gear. Even if the switch appears to be working if the computer does not recognize that the motor is in gear it will rev limit the motor. The motor will appear fine right up until you hit the limiter rpms. 2500 in this case. No system check alarm will happen.

Now, you described that you may have to baby the throttle or feather it if you will to get throttle response?

 

[rdlone]

FOUND THE SWITCH ON THE LINKAGE AND IT IS A SIMPLE OPEN CLOSED CONNECTION. FOUND A CONNECTOR BEFORE WIREBUNDLE AND CHECKED OPEN /CLOSED STATE WITH OHM METER AND MOVING THROTTLE.
MOVING THROTTLE SLOWLY LET'S ME GET UP TO LITTLE MORE THAN 2000 RPM WITHOUT CUTTING OUT/CHUGGING. BUT IF I MOVE THROTTLE TO FAST IT STARTS CHUGGING SOONER.
vacuum checked the map sensor and voltage changes with vacuum increase.

 

[jakedaawg]

Sounds like the switch is not your issue.

Just want to be sure that the spark plugs have been replaced. Does not matter how good they look, they go bad and create misses.

You mention struggles with the lift pump...sounds like you converted to an electric? I wonder why, they are easy to replace. If you had multiple failures was the cam shaft inspected? The lift pump runs off a cam lobe...anyways on to the next thoughts...

In the high pressure pump there is a regulator and a screen as well as some rubber parts.

Get a fuel pressure guage and connect at the Schrader valve. Report pressure while HP pump is running and residual pressure.

There is also an expensive HP fuel filter. Check records from dealer service to see if it was changed. Speaking of which, I assume the LP filter was replaced.

I also assume that spark has been verified as well as a compression test with throttle wide open.

 

[jakedaawg]

Like I mentioned earlier, just because the switch test well does not mean that the computer actually recognizes this. Bad wiring or a faulty emm can lead to symptoms almost exactly like you state.

When you say it chugs are you hitting the rev limiter? This is plainly evident as it will run smooth right up until the limit and then buck and such.

Just read that you said two mechanics...Do you know if either has the factory software? 4sDs it was called.

 

[rdlone]

Headed out of town for weekend , will take up fight next week. Plan on fuel pressure check next week. Lift pump problems were leaking fuel into crankcase, after 3 pumps switched to electric pump. Will read dress that problem after getting engine running at full rpm. Thanks for your help, hope to continue next week. Regards

 

[jakedaawg]

3 lifts leaking? Wow, sure it was the pumps and not leaky injectors? With lift pump detached from motor squeeze bulb. Does fuel spit out?

 

[rdlone]

Went to start and only clicking. Battery good and have pulled starter away front
fly wheel and does same thing. See price on new one extremely high. Rebuild possible?
2nd question on shift position sensor. Does that have voltage running thru switch or just provide ground ?

 

[racerone]

Clicking means a low battery / dirty contacts / bad cables.--------???----Not sure why you immediately think new starter required !!----Have your battery LOAD tested.----Inspect cables and connections

 

[oldboat1]

On the fuel side, I would replace both the lift pump filter and the injection pump filter. Best guess is that somebody ran a purge or two, but didn't replace one or both filters afterwards. Think Jakedaawg's suggestion re. filters in #13 is a good one.

If you check with the mechanic(s), see if they replaced the filters, ran a purge to clean the injectors -- and whether the filters were changed after the injectors were cleaned. Should check the procedure too. I had a mechanic run a purge in the tank, then didn't change out the filters (diesel auto). Symptoms real similar to what you describe. I changed out the two filters and found debris in each -- no more stumbling after the filter changes, but big $$ spent (lift pump replacement included).

 

[jakedaawg]

Re: fuel side...no further suggestions until fuel pressure values listed. There is about .01% chance that 3 lift pumps were bad. Something else is going on, leaky injector or injector stuck open. There is a noid light test for those outlined in manual but that's just looking for signal from emm. 4sds software will be needed, as that's the cheapest way to diagnose.

as far as starter...racer covered that well.