2008 DF90 won't start.

knagy20

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Hi all. New here. Have a 2008 DF90 that stopped running while out on the water back in September. Prior to it not running, the motor would not go over 3000rpm unless it was started multiple times and we had to wait several seconds after the beep stopped to start the motor. Motor will crank, but won't start. It is not and has not thrown any codes during the episode. I checked all the usual suspects like fuses, white wire, wire corrosion, fuel delivery and quality, etc. I have the Suzuki software and service manual and have followed all the tests which led me to a bad ECM. As recommended on another forum, I have replaced the ECM and the IAC valve, but the motor still won't start. Went through all the tests again and ended at a bad ECM. Replaced that again and it still won't start. The bad tests are: injectors not clicking and only 1.1 volts to injectors upon cranking. Need help for other possible causes.
 

lakensea

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The results you provide, if done properly, do NOT lead to a bad ECM. I suggest you read the troubleshooting chart more closely.
 

knagy20

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The results you provide, if done properly, do NOT lead to a bad ECM. I suggest you read the troubleshooting chart more closely.
If you could, please show me where I went wrong.
 

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lakensea

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It's right in your original post - re-read and follow the troubleshooting chart.
 

knagy20

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It's right in your original post - re-read and follow the troubleshooting chart.
So. I'm not seeing the problem, that's why I'm asking for help. Guess I'm dumb. How about telling me where I'm going wrong. I can't figure it out!
 

knagy20

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In an attempt to clear some obviously muddy water, I have re-read my original post and left out some possibly important information. I have the Suzuki diagnostic software. You can test the function of the injectors from the program. All 4 injectors DO click during the test at a rate of approximately once per second during the 5 second test. Resistance and all other tests on the injectors are within specs except that they don't click on cranking and the voltage on cranking is 1.1 volts not 6-10 volts as specified. The latest test was performed with a new ECM on the initial crank. Looking for reasons other than a bad ECM for the poor voltage.
 

lakensea

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Look at the chart - where does insufficient injector voltage lead you?
 

99yam40

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Look one block above the ECU failure block if the voltage in not OK on those 4 points
 

knagy20

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< Cranking > Check injector operating sound. Is result OK? – NO SOUND

< Ignition switch “OFF” >Check fuel injector resistance. Is result OK? – YES 13.5-13.8 ohms

< Ignition switch “ON” > Check “22, 38, 39 and 40 terminal voltage. Is result OK? – YES 12.6v

< Cranking > Check fuel injector operating signal. Is result OK? – NO 1.1v

I have replaced the ECM TWICE. The last one was at 1.1v out of the box. If you are taking me down the Power supply wire (Gr) failure, I have 12.6 v when performing that test which is what the battery is testing at. Before starting this post, I replaced both the ECM Main Relay and the Started Motor Relay with no luck. From the wiring diagram, it looks as if the GR wire services most if not all the sensors. I’m not throwing any codes, nor have I ever thrown codes
 

lakensea

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You can keep wasting your money and throw parts at it, or believe & follow the troubleshooting.

Why did you replace the relays?
 

knagy20

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Glad to see you get off on the frustations of others. I replaced the relays because they are cheap and easy to do just like the fuses cheap and easy. You keep being criptic and say follow the guide. I am. It keeps leading me to a bad ECM and at $2k I don't want to to keep throwing money at it. I've asked you several times to be specific and yet you keep on being vague. I can play this game a long time. I have no problem filling your ego.
 

lakensea

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Unbelievable. What does low voltage at the injectors indicate? LOW VOLTAGE IN THE GRAY WIRE CIRCUIT!! It does not indicate a bad ECM, relay or fuse.
You're not filling my ego. 99yam40 and I have both told that.

I do not have the engine here, so I cannot find the weak spot for you.

Just trying to help you figure it out for yourself, with just some nudging.

Like the old saying goes, give a man a fish, he eats for a day. Teach him to fish and he eats for a lifetime.
 

99yam40

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If you have good voltage with just the switch on and not during cranking,
I would think the cranking is pulling down the voltage or you have a ground problem.
have you checked other places to see what voltage is showing while cranking?
 

knagy20

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Ok. So, let's reset this. I apologize for my attitude, no excuse.

The test for the gray wire is key on and check terminals 22, 38, 39 and 40. I have 12.6 volts upon testing which per the manual is the correct voltage. It is when I crank the motor and test I have bad voltage. So you're saying even though its passing the test for the gray wire, it's a bad gray wire? Ok, answer accepted. Bad gray wire. Outside of checking every one of them individually, do you have any suggestions or tests I can do to find the problem? A new engine harness is like $600. I have already done continuity tests on the injectors and haven't found a problem. But if you have a better way, I'm open for all suggestions.
 

knagy20

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If you have good voltage with just the switch on and not during cranking,
I would think the cranking is pulling down the voltage or you have a ground problem.
have you checked other places to see what voltage is showing while cranking?
If there is a grounding problem, it has to be in the motor somewhere. The battery is located in the center console. After replacing the the first ECM, I took the battery out of the console, bought new, oversized, short cables and hooked the battery up straight to the cables. No battery switch, fuses or anything. I've made sure the terminals on the motor were clean and tight. I've even used other batteries, including the one out of my truck. No luck. I haven't had anything test bad, and I done almost all the voltage tests and continuity tests in the manual.
 

99yam40

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Since I know nothing about this motor, I have to ask where was the places you checked the voltages?
right at the ECU?
were the wires hooked up to those terminals when you did the tests?
Did you test without them hooked up?

can you test the voltage to the ECU or relays during cranking to see if it also is dropping?

where are you placing the negative lead of the meter during the testing?
 
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