225 Optimax DFI startup

[Jack Peck]

2000 Mercury Optimax DFI revving up to 5000 rpm at initial startup for approx 5 seconds, then settles to normal idle approx 650-700rpm. Seems to only happen when engine in cold. Put on diagnostics, no warnings/issued noted. All system checks show "passed" Have all detail of diagnostics printed out. Any suggestions for a starting point to troubleshoot this issue will be greatly appreciated.

 

[Dan J.]

Just wanted to leave this at the top for Bob B. or others with knowledge and/or access to MercNet. The early Opti's had a slough of TBI's and I'd hate to guess. If I did guess, I'd hope for a TPI/TPS problem. Less pain on the hip. Good Luck!

 

[Jack Peck]

Dan,



thanks for replying. sorry for the ingnorance. TBI stands for ???

 

[Bob Bourget2]

Jack, are you by chance "working the throttle" at all before you start it?

 

[Dan J.]

TBI/TSB - Technical Bulletin Issued/Technical Service Bulletin



They're service dealer alerts for issue(s) found per model.

 

[Jack Peck]

Bob...not working any throttle. After two failed starts today, third attempt started with high rev and settled to approx 750 rpm. Idled a little rougher than i am used to. The engine light came once but didnt stay on. Had throttle position mechanism replaced in fall of 2010. Worked fine in spring thru summer 2011. I repositioned my hotfoot last summer when it came loose. Not sure if the cabling needs tension adjusted. do you think the cable my be "advancing the throttle" during startup? The hotfoot seemed a little tighter? Thanks for you thoughts/ideas?

 

[Bob Bourget2]

No problem Jack. First things first though....

-1] Start by basic link and synch with your throttle cable foot throttle. Make sure all of the stops are adjusted correctly, and you are truly getting wide-open-throttle, WITHOUT USING ANY OF THE MOTOR MOUNTED LINKAGE AS THE TRUE "STOP". The only stop should be at the foot throttle!!

-2] Have your Dealer do a TPS sweep. You should see a linear movement from idle to wide-open throttle, with no abrupt changes. If it is not smooth, especially just off idle, replace it.

 

[Jack Peck]

Bob, tech did the TPS sweep, as per him, no issues were indicated. i have the printout on hand. let me know if that would help. i can scan and email to you. we discussed the hotfoot situation, said that i can disconnect the throttle cable at the motor to eliminate any cable issue at the hotfoot. doesnt think my hotfoot is the issue. will try this tonight.

 

[Jack Peck]

Problem fixed by changing out fuel stabilizer diaphragm on port fuel rail. See www.thepelicanservices.com Many optimax owners may be experiencing same/similar situations. Call Todd Moore (The Pelican Services) to see if your Optimax issues can be resolved by replacing the diaphragm. This is not the Tracker valve that shows on the OEM parts list. Good luck to all Optimax owners and thanks for the suggestions to my post.

 

[Bob Bourget2]

Great info...I did not know they even existed.....!!!!Glad it's fixed and running well.