Here is my Tune Up Kit - Advice Wanted

[vigalass]

I'm back at the lake now. Aiming to fix my 250 Optimax 2002 that keeps dying after about 10mins of driving through no wake; and then won't restart for 30mins. Then will hard start and die again in another 10mins.

Here is my plan. I welcome input on the order and blind spots.

0) hook up fuel and air pressure gauges (already checked them at 95 and 85 fuel and air)
1) check the crank trigger wires for insulation delamination
2) pull current plugs and replace all six
3) replace port temp sensor
4) idle test and pull out each injector one at a time to see if the idle changes to see if all 6 are firing.

If all 6 are idling then Test Drive - bring can of fuel. If it dies pull feed fuel directly from clean fuel can

4) if won't start install 6 inline spark testers and monitor spark while driving
5) install new Crank Position Sensor

test drive - if still dies. return to dock and

5) pull fly wheel and investigate crank trigger equivilent on this DFI

6) replace each fuel pump starting with cheapest first and test driving.

I shoudl weave in seeing if i have a throttle gaurdian and kill it, and look for the black/yellow wire and snip it.

And pull tether switch out and bypass.

If this doesn't work I have a boat for sale!!

Victor

 

[Maximus82]

What tool do you use to remove/change the temp sensors? Mine are on pretty tight and can’t seem to get it to budge with a wrench. Can’t find a 13MM Sensor Socket.

 

[vigalass]

Max. i was thinking of you about 45mins ago. I changed my temp sensor. It was a 15mm open end wrench. Now it's kind of a bear to get a hold of. 1) i pulled the top spark plug out. unplugged the injectors plugs to make room. Then it's kind of a matter of find the right angle on the wrench so it just bites enough to catch. Remember to go counter clock (sorry but making sure). The thing is made of plastic. I finger tightened my new one in then justs needed a qtr turn with the 15mm wrench to seat it.

Someone may have cranked it in there . as a last resort you might try to get a flat head screwdriver on the edge and tap with a small hammer to just try to break it loose. I think it will work. this assumes you have a new one to use as a replacement.

Best luck.

 

[Tim75]

I'm back at the lake now. Aiming to fix my 250 Optimax 2002 that keeps dying after about 10mins of driving through no wake; and then won't restart for 30mins. Then will hard start and die again in another 10mins.

Here is my plan. I welcome input on the order and blind spots.

0) hook up fuel and air pressure gauges (already checked them at 95 and 85 fuel and air)
1) check the crank trigger wires for insulation delamination
2) pull current plugs and replace all six
3) replace port temp sensor
4) idle test and pull out each injector one at a time to see if the idle changes to see if all 6 are firing.

If all 6 are idling then Test Drive - bring can of fuel. If it dies pull feed fuel directly from clean fuel can

4) if won't start install 6 inline spark testers and monitor spark while driving
5) install new Crank Position Sensor

test drive - if still dies. return to dock and

5) pull fly wheel and investigate crank trigger equivilent on this DFI

6) replace each fuel pump starting with cheapest first and test driving.

I shoudl weave in seeing if i have a throttle gaurdian and kill it, and look for the black/yellow wire and snip it.

And pull tether switch out and bypass.

If this doesn't work I have a boat for sale!!

Victor

#4- while it will run, pull spark plug wires one at time, watching for rpm change. CAUTION- there's lots of volts in those wires!

 

[vigalass]

Update on my boat.

Changed crank sensor. Changed port temp sensor. Put in a new injector where I suspected i had a problem. New plugs. Installed inline spark indicators so i can see if i'm getting spark. I am getting spark at all times on all 6.

Installed fuel and air pressure gauges. The delta is 10PSI and fuel is about 95PSI. Perfect.

So I've concluded its some sort of fuel problem. i did take all 3 pumps apart about 3 weeks ago when this started and bench tested them a while back. The all passed a 12v bench test, but i didnt' check ohms. But i read here somewhere that a guy had the same problem it woudl run then stall. Then not restart until the fuel vacuum would dissipate. Either his lift or low pressure pump was getting vacuum locked. So I'll start replacing pumps tomorrow.

I do need Tim's input on one thing. While i was waiting around for the motor to cool (fuel pump vacuum to dissipate) I tried to clean up the oil fill reservoir. I noticed the oil fill cap was CRAZY tight. I broke it loose and on a hunch I tried to start it with the oil cap off. It fired. I closed the oil fill cap and it died. Then I opened it and it started. I ultimately ran it do the dock for abou 4mins at 2k with the oil fill cap off. I know that's bad but temp was low.

Does this inform any thinking for you? Have you every heard of some sort of fuel/oil vapor lock?

Thanks

 

[AirSniper]

May or may not be helpful, but as a theory, try venting the gas tank...had an outboard act like this because the tank wasnt vented and the pump eventually couldnt pull gas. when it dies, open the gas cap, listen for air inrush.
Hope thats it, seems the cheap & easy fix.

 

[Tim75]

Update on my boat.

Changed crank sensor. Changed port temp sensor. Put in a new injector where I suspected i had a problem. New plugs. Installed inline spark indicators so i can see if i'm getting spark. I am getting spark at all times on all 6.

Installed fuel and air pressure gauges. The delta is 10PSI and fuel is about 95PSI. Perfect.

So I've concluded its some sort of fuel problem. i did take all 3 pumps apart about 3 weeks ago when this started and bench tested them a while back. The all passed a 12v bench test, but i didnt' check ohms. But i read here somewhere that a guy had the same problem it woudl run then stall. Then not restart until the fuel vacuum would dissipate. Either his lift or low pressure pump was getting vacuum locked. So I'll start replacing pumps tomorrow.

I do need Tim's input on one thing. While i was waiting around for the motor to cool (fuel pump vacuum to dissipate) I tried to clean up the oil fill reservoir. I noticed the oil fill cap was CRAZY tight. I broke it loose and on a hunch I tried to start it with the oil cap off. It fired. I closed the oil fill cap and it died. Then I opened it and it started. I ultimately ran it do the dock for abou 4mins at 2k with the oil fill cap off. I know that's bad but temp was low.

Does this inform any thinking for you? Have you every heard of some sort of fuel/oil vapor lock?

Thanks

I believe you have a fuel pump that is crankcase vacuum/pressure pulse operated. It's tucked in close to the block. I think you need to check the delivery of this pump. I am not sure about fuel/oil vapor lock. There may be a small check valve somewhere in the line that pressurizes the large oil reservoir tank. It kind of seems that your tank is being pressurized by the same connection that operates the pulse pump. That would explain why engine dies after a few minutes. Pressure would build in the oil tank and "lock" the pulse pump. (It needs vacuum & pressure.)

 

[Maximus82]

Max. i was thinking of you about 45mins ago. I changed my temp sensor. It was a 15mm open end wrench. Now it's kind of a bear to get a hold of. 1) i pulled the top spark plug out. unplugged the injectors plugs to make room. Then it's kind of a matter of find the right angle on the wrench so it just bites enough to catch. Remember to go counter clock (sorry but making sure). The thing is made of plastic. I finger tightened my new one in then justs needed a qtr turn with the 15mm wrench to seat it.

Someone may have cranked it in there . as a last resort you might try to get a flat head screwdriver on the edge and tap with a small hammer to just try to break it loose. I think it will work. this assumes you have a new one to use as a replacement.

Best luck.

Thanks for the advice. It turned out to be a 14MM and was able to switch one sensor out but someone had applied putty to the temp sensors and glued them in place. when I went to remove the other it broke off and now I have to drill it out somehow. Not great!

 

[vigalass]

good lord. figures. you may consider a light torching or heat gun air to heat it up to soften the putty a bit. probably should ask Tim how that temp sensor touches the oiling and cooling jackets in the head. You don't want to drill and get shards inside the block if that temp sensor flows in to the pistons and crank.

heating sounds better than drilling. if you do make sure to remove all wiring

 

[Maximus82]

I am going to attempt to use a bolt extractor with some penetration oil tomorrow. Update: Got the bolt extractor perfectly in Place and it was able to bite but the sheered Sensor still won’t budge. That sucker was really glued on. I’m trying really hard not to damage anything. Going to let the penetrating oil sit for a day and will try again tomorrow. Crazy about 6-8hrs on these sensors. If I did get debris inside the temp Sensor receptor, could it damage the cylinders or is it just a cooling clog risk? Diagram shows it flowing right out to the drive.