1998 ficht 150 Johnson idle

Brisfisher

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Jan 26, 2014
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I've been having problems with getting a good idle with this engine, I have changed the plugs,oil and fuel. After running the engine for a few minutes and remove the plugs to inspect plugs 3-5-6 are not firing and come out clean. I have ran the scan tool and only fault that comes up is crank sensor( this comes up when the engine stalls). I have static tested the injectors and all are working also ran the engine with spark testers and a all have spark. It looks as though there is no fuel at idle to these cylinders. Any advise would be appreciated, thanks
 

seahorse5

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Re: 1998 ficht 150 Johnson idle

How are you numbering the fouled plugs?

3 and 5 are the middle and lower stb. side plugs and #6 is the bottom port side plug.
 

boobie

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Re: 1998 ficht 150 Johnson idle

Have you ran a cylinder drop test to make sure you know which cylinders aren't firing?? You can do this on your laptop.
 

Brisfisher

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Re: 1998 ficht 150 Johnson idle

Yeas I've run a drop test and the cylinders I mentioned don't have much affect, I believe they are sparking but have no fuel?
 

Brisfisher

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Re: 1998 ficht 150 Johnson idle

I have also swapped injectors from number 2 to number 5 and run at idle to confirm, there was no change both cylinders still the same.
 

boobie

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Re: 1998 ficht 150 Johnson idle

If I read this right, that sounds like a fuel supply problem to the injectors.
 

Brisfisher

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Re: 1998 ficht 150 Johnson idle

I thought the same so I did a pressure test it is within spec. It's got me stumped, I had read these engines drop cyl to maintain idle but wouldn't think it would be the same three all the time?
 

emdsapmgr

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Re: 1998 ficht 150 Johnson idle

I'm no Ficht expert, but aren't the Ficht injectors programmed (for proper flow characteristics) into the computer by cylinder location on each head?
 

boobie

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Re: 1998 ficht 150 Johnson idle

The newer ones were but in 1998 I believe you could swap injectors with no problems. Then OMC found out they couldn't make them all the same due to their poor manufacturing processes. So they tested them in the factory and put the coefficients on them you had to match up with the EMM. And you needed a laptop and a disc to do this.
 
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Faztbullet

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Re: 1998 ficht 150 Johnson idle

Could be a bad/weak ignition module as only the 97-99 motors had them.The spark should jump a 3/8 gap and be blue. If its weak the cylinder compression will not allow plug to fire...
 

Brisfisher

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Re: 1998 ficht 150 Johnson idle

I have used the led spark testers but will try will the older one today and see how it looks, thanks for the input.
 

Brisfisher

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Re: 1998 ficht 150 Johnson idle

Ok so I've checked the spark and all cylinders are sparking very well, is there anything else I should check? A fails code pin13 also came up?
 
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