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ISM 450 Slow to Start

November 04, 2012, 03:34:09 pm

Howdy Everyone,

  The last several start-ups on our coach, the engine has been slow to start.  That is: it cranks much longer than normal, starts, hesitates, sometimes dies, then will re-start just fine, then runs great (knock on wood).  I feel certain I have a fuel issue and there's lots of information on the forum on fuel filters..I think the PO may have installed the Racor retrofit kit:  Racor RK12963 Retrofit Kit
The fuel filter system looks just like Barry has described.  See photos.
All the strings point to maybe the Winn Screen type clear filter o ring. I have had this filter replaced several times at the regular fuel filter changes.  How would I know that there is air leaking around the o rings?  When the coach is running there is lots of turbulence in the upper portion of the clear filter.  I have a spare Clear Winn screen/filter pn 300200 with o rings.  There is a thumb screw on top of the filter assembly.  If I  were to loosen this thumb screw, could I remove the screen type filter?

Thanks for your help,  Dave A

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Re: ISM 450 Slow to Start

Reply #1 – November 04, 2012, 03:38:54 pm

Yes that was my symptoms too.  Replaced with the Racor system and no problems since.  Also per 01 on the 450s there were 28 updates to the ECM and 11 of them dealt with hard starts. 

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Re: ISM 450 Slow to Start

Reply #2 – November 04, 2012, 03:43:30 pm

Howdy John, Thanks for your reply.  Exactly what is the Racor??  I think I have a Racor Integrated system, that includes the clear Winn Filter.  Do you have a link to what you installed?  Does it do away with the Winn Screen filter?
Concerning the chip upgrades.  If I remember correctly from you previous posts, that if during the chip upgrade, if the chip dies, that is on the owner??
Again, thanks for your help Dave A

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Re: ISM 450 Slow to Start

Reply #3 – November 04, 2012, 05:16:38 pm

this is what my 2001 system looks like after the conversion, will try to find my "before" photos....

Mike

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Re: ISM 450 Slow to Start

Reply #4 – November 04, 2012, 05:18:10 pm

oops, here is another after conversion photo of the larger area,  Mike

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Re: ISM 450 Slow to Start

Reply #5 – November 04, 2012, 05:22:12 pm

Howdy Michael,  Thanks for the feedback..Was your filter system orginally in the Chassis battery area?  Did you have it re-located?  Did you do this at MOT?
Thanks for your help, Dave A

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Re: ISM 450 Slow to Start

Reply #6 – November 04, 2012, 05:24:27 pm

Ok Dave, I found the before conversion, hope this what you needed in terms of photos....Mike

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Re: ISM 450 Slow to Start

Reply #7 – November 04, 2012, 05:26:27 pm

Dave, replace the unit with the Racor 790r30,if I ever figure out how to post a link, I will be in good shape.

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Re: ISM 450 Slow to Start

Reply #8 – November 04, 2012, 05:30:23 pm

Dave, this was and is on the rear of the engine.  I have a filter around in the battery area.  It was done by MOT at suggestion of Keith Risch and a few friends here on the forum. 

It was not inexpensive but I lack the experience and confidence of some of you with huge experience that I can find civilization if I break down on the road!  This was said a possible weak link in my coach's running. 

You did not ask for more, and I doubt this relates in any way but.....As for starting problems, mine when buying was related to the starter (140,000 miles).  A gentleman I met, getting work at MOT, suggested I put a cable from the ground of the chassis batteries to the chassis, that the ISM takes a lot to crank.  I did that but still had sluggish starting.  MOT checked then the amp draw on the starter, replaced starter.  Since then starting is easy but I always, always, use the boost to give enough rpm.  Mike

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Re: ISM 450 Slow to Start

Reply #9 – November 04, 2012, 05:30:59 pm

Howdy Michael,  Thanks for the photos...The befores look like what I have, except mounted in the engine compartment (much better location).  Did MOT do this for you???

Howdy Bill, Thanks for the feedback..Is this it?  790R30 FILTERPUMP (12 VOLT)

Thanks for all the help/advice...Dave A

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Re: ISM 450 Slow to Start

Reply #10 – November 04, 2012, 05:32:27 pm

That's it.

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Re: ISM 450 Slow to Start

Reply #11 – November 04, 2012, 07:49:34 pm

On my 2000 it was over the batteries on my 01 which was made in 2000 it is in the rear by the engine and it looks like the new one you showed.  I had to have a plate made up to move it up a bit.

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Re: ISM 450 Slow to Start

Reply #12 – November 04, 2012, 07:54:58 pm

Here are some documents. Racor docs show the new system. Winn doc describes the old.

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Re: ISM 450 Slow to Start

Reply #13 – November 05, 2012, 06:56:22 am

Howdy John,  Thanks for the info...Re-locationg to the enginge compartment looks like the best way to go...I'm going to look into having that done..

Howdy Dave,  Thanks for all the detailed information...I've printed/saved all of it for future reference..

This forum is the best!!!  Dave A

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