2006 DF150 Suzuki turns over several times before cranking

[Bcribb]

My 2006 DF150 Suzuki cranks over several times before starting up. It don't matter if the engine is hot or cold. It also hesitates and sometimes shuts off when easing up on the throttle. I've installed new plugs , had injectors cleaned, replaced IAC valve , changed fuel filter water separator and cleaned fuel tank. The engine runs perfect after it gets past the hesitation. I need help on whats causing the hard start and hesitation. Thanks for any suggestions..

[STxFishing]

Maybe voltage issue? Are cables clean at both ends? Sometimes they rot in the hull/compartment and are stiff and brittle on inside of casing.Check along the cable length for crunching(if possible) or try running jumper cables. I'd do a voltage drop test on battery(s) as well. Check battery kill switch too, if you have one.

[artdf175]

when you turn the key, you should hear the high pressure fuel pump kick in
runs 4 or 5 seconds to charge the fuel rail
Are you waiting for that procedure to finish before hitting the starter?

[Bcribb]

Yes. The hesitation on slowing increasing the throttle is what bothers me most. It's just a small hesitation but sometimes when it hesitates the engine shuts down.

[Bcribb]

Maybe voltage issue? Are cables clean at both ends? Sometimes they rot in the hull/compartment and are stiff and brittle on inside of casing.Check along the cable length for crunching(if possible) or try running jumper cables. I'd do a voltage drop test on battery(s) as well. Check battery kill switch too, if you have one.

The cables are clean and have been replaced recently. I also have a 2 battery set up and both batteries are fully charged. I was thinking it might be ignition timing or faulty coil

[Bcribb]

Yes. The hesitation on slowing increasing the throttle is what bothers me most. It's just a small hesitation but sometimes when it hesitates the engine shuts down.

Also could the ignition timing cause it to do this?

[artdf175]

when were the valve clearances checked? how many hours on the engine?

[Bcribb]

when were the valve clearances checked? how many hours on the engine?

750 hours on the engine. The valve clearance hasn't been checked that I know of. I've had the engine for 3 years and it was hesitating a little bit when I bought it

[catacom225]

Hi Bcribb! which of the fuel filters have you changed low or hi pressure, or just the fuel/water separator, a lot of problems on these engines are fuel related, either boats lift sitting for long periods or a bad batch of fuel etc. replace hi and low pressure filters, have the VST checked and cleaned and then reply with the result

[Bcribb]

Sorry for the late reply I've been busy with other things and finally got to work on my engine. I removed the vst tank and it was clean. The only thing I saw wrong was the rubber grommet that the hp pump fits into and it was breaking apart. I replaced it with a new one. Put it all back together and its doing the same thing. I also put another aic valve on and that didn't help. When giving it a little gas it hesitates and sometimes shuts down. I haven't changed the hp filter yet. I have ran a gas line straight to an auxiliary tank to the engine also bypassing the fuel water separator. Other than that problem it runs great. I feel like its something simple that i'm missing..

[Bcribb]

I haven't changed the hi pressure fuel filter. I have checked the vst tank and its clean as well as the strainer on the bottom of the pump. I guess i'll change the hp fuel filter and see if that helps.

[artdf175]

do you have the manual for adjusting the IAC valve properly?

[Bcribb]

I've read while the engine is running turn the key to the start position 5 times and you'll hear a beep. Then adjust the rpm's as needed ? Is that right?

[artdf175]

I've read while the engine is running turn the key to the start position 5 times and you'll hear a beep. Then adjust the rpm's as needed ? Is that right?

well that is part of it.. how far out of the range is the RPM's. The IAC valve is the adjustment for getting the RPM to be between 600-700 RPM's
you need to remove the fuel hose guard,, with the engine warm and running in neutral, you need to fully close the throttle.. then turn the key to start 5 times in 10 seconds
you should hear the caution buzzer sound and continue to sound while in this fixed mode.. you have 5 minutes to adjust the rpm to the correct range

the IAC should not be the problem with the hesitation .. if it is dirty it could effect the control of the engine when you decelerate from higher rpm's

You should check all the engine sensors to be sure they are working correctly
you should check the valve clearances.. these should have been checked and adjusted at 200 hours and ever 200 hours after that..
Do you have the engine manual for doing all these procedures?

and question: re the hard start... are you waiting the 5 seconds after you turn the key to "on" for the high pressure fuel pump to bring the fuel rail up to pressure?
you should be able to hear the pump.

Art

[Bcribb]

I wait the 5 seconds before starting the engine. I have a suzuki manual.I haven't found the IAC adjustment method for the 140. If the IAC was not set right would the engine start sometimes and then sometimes not start. Seems strange that it starts right up and when I shut it off and try to start again it just spins over. I turn the key off and try to start again and it fires right up. Shut it off and try to start and it just spins over and don't try to crank. Turn the key off and go to start again and it cranks up.. Pretty frustrating..