POOR HOLE SHOT : WARM WEATHER ONLY

[lpugh]

Leon Pugh leon.pugh@comcast.net 916 813 0321
02 225 optimax SN 0t469064

Hope to hear from Don on this one
02 Bass Cat Cougar 73 mph @ 5700 with a 26 Fury normal load when cool, 70 latter in the day with full livewells
Severe bog on hole shot, does not feel like a misfire, runs smooth, just feel like to much prop that is not vented. Only happens above about 80 deg air temp and 65 deg water temp. Great hole shot when cooler. Problem is worse after hot soak. Also has a minor surge at fast idle in gear 12 to 2200 rpm only when warmed up
Top end is fine, very smooth idle

405 hours since power head and lower units were replaced
recent: spark plugs correct OE replacements, Fuel filter, compressor filter, two new injectors, inspected and cleaned out vst
87 octane fuel and premium plus oil with quick clean allways

Old plugs looked very good except for minor oil/fuel fouling on #two
Compression variation within 5 psi

When I got this boat 2 years ago it had a fuel gauge issue and power got applied to the sending unit. Some how this overloaded the sensor ground circuit (black/orange wire) causing it to open circuit in the computer thus the computer received maximum voltage signals form all sensor using this isolated ground,
The quick temporary repair was to jump this wire to engine block to supply a ground. As expected there were a few minor issues as result. Yes I do understand filtered isolated circuits and how it relates to voltage seen at the computer.

This current problem just started recently and is getting worse as the ambient temps increase.

Verified no spark degradation while problem was occurring
low pressure pump has 25 psi HP running 93psi Air 83psi
no air bubbles at fuel test port hot or cold
Fuel pressure holds steady for at least 10 minutes after shut down at 25 psi, drops instantly to that value when shut off

I removed fuel rails and connected to a automotive injector cleaning machine (motorvac). No leak down at all during 1 hour leak test
I measured relative injector flow and found #3 and 5 were 10% lower than the rest. Cleaned injectors and there was no change. Those to injectors were replaced
Results were a smoother idle and a little better throttle response

Used a lab scope to verifie TPS is good, range tested map sensor, ats and cts

I replaced the computer with a used one and removed the ground wire. Started fine and ran well on the muffs. Went back to start it a half hour later, went 2500 rpm, constant alarm and over rev displayed. Guess WHAT..... open circuit in computer for sensor grounds

Any thoughts or advice would be appreciated, I am not looking forward amp flow testing every black/orange wire in the system
Got find the culprit before it gets another computer
Can this circuit be repaired????

Thanks to all Leon Pugh

[Shef]

My experience with Bass Cats tells me you are definitely running too much prop. The max for a Cougar with a 225 would be a 25 Fury with all vents open and depending on outside air temp it may need extra 5/16 vents. I did however have a similar problem with my 2005 Puma/Merc Racing 250XS that only Don was able to fix. Yes I took my boat from S. Florida to Greenville! It ended up being the reed standoff was too much. First thing I would try is the prop.

[JOE54]

standard opti 26 fury= too big/put a known unaltered 24 fury no plugs in, on it and go run it, or 25 tempest unaltered one large hole plug in

[Savage]

Your chasing a ghost......not a motor problem if it runs good with cooler temperatures. Change prop pitch as suggested.

[JOE54]

conditions affecting performance page 1c-2 serv manual 859769R03 engines may lose as much as 14% on hot humid day

[lpugh]

Come on guys read the post completely, 5700 on a warm day with full livewells, hits the limiter in cool weather and empty wells. Not the Prop, By the way Ronnie Gilbert reworked this one for me. Rev limiter is 5750 on this motor

I had a similar problem on a old EFI that was caused by restricted idle relief ports. Seems the Opti adaptor is different in this regard

[JOE54]

pull gearcase, same idle reilfs, running smart craft tach or check rpms with cds???????

[lpugh]

Smart craft, I have no reason to doubt it since it hits the limiter at 5750 and prop calculations come out @ 9%.
I did not have this issue last summer in much hotter weather
I am very concerned about the sensor ground ckt failure. I am suspicious the smart craft may be inducing a higher B+ voltage thus overloading this circuit
I will be checking current flow and open ckt voltage sensor grounds tonight

[Shef]

Read the first one completely. You left out that one major detail about Ronnie working your prop.

[06 SB]

You have completely lost me with the issues of your engine. It might be worth taking it to Don if that is feasible.

This may not be an engine issue though. I know it is not uncommon to need extra venting for Cougars/Pumas. I would think that a 225 Optimax would especially need it. Another option is a ‘foil from CBailey.

[Savage]

Electrical problems can NOT tell what the ambient temperature is......If your problem happened in ANY ambient temperature, cool, warm, and hot, then that would be a different story.

[leo13]

My friends had a similar issue and it was the reeds. A few of them had the corners broken off.

[Savage]

Bad reeds can cause performance issues, but those REED issues would still be there in cool temperatures.

[lpugh]

I don't believe the two problems are related, but I learned a long time ago not to make that assumption. Electrical problems are can and quite often are heat related. That is how most MAF sensor function. A hot wire that is cooled by air flow over it which causes increased current from the cooling of the wire, the PCM knows the ambient temp and the current flow thru the wire thus it can measure air flow very accurately. All sensor circuits are very sensitive to this. A poor connection may not increase resistance enough at 50 deg to be a problem but at 90 deg it may push it over the edge.

[Savage]

Yes but there is no Mass Air Flow sensor on you motor. The difference between 50* and 80* is not going to cause an electrical issue on your motor. The motor is ALWAYS running at a temperature higher than the ambient temperature.

[EuropeanAM]

02 225 optimax SN 0t469064

When I got this boat 2 years ago it had a fuel gauge issue and power got applied to the sending unit. Some how this overloaded the sensor ground circuit (black/orange wire) causing it to open circuit in the computer thus the computer received maximum voltage signals form all sensor using this isolated ground,
The quick temporary repair was to jump this wire to engine block to supply a ground. As expected there were a few minor issues as result. Yes I do understand filtered isolated circuits and how it relates to voltage seen at the computer.

This current problem just started recently and is getting worse as the ambient temps increase.

........
I replaced the computer with a used one and removed the ground wire. Started fine and ran well on the muffs. Went back to start it a half hour later, went 2500 rpm, constant alarm and over rev displayed. Guess WHAT..... open circuit in computer for sensor grounds

Any thoughts or advice would be appreciated, I am not looking forward amp flow testing every black/orange wire in the system
Got find the culprit before it gets another computer
Can this circuit be repaired????

Thanks to all Leon Pugh

See the RED/BOLD text in your above quote.

Never, Ever should the Black w/Orange Stripe 5V PCM Ground Reference be tied into a 12V Ground (or power) Circuit. Doing so will burn out the Ground H-Bridge in the PCM, rendering most 5V circuits non-functional.

Since you jumpered the original to ground and apparently ran it that way for some time, I would probably NOT be inclined to send in that PCM. I believe Simon Motorsports has the ability to replace/repair the H-Bridge circuit (call and ask Eric).

Check the Fuel/Oil/Paddle harness in your boat. EARLY models of this harness had a black w/orange stripe wire (which should NOT have been connected at the tank). Tank must be grounded for static discharge protection (12V Battery Ground)... so this caused problems when a 5V ground was used. Later harnesses simply ELIMINATED the Black w/Orange Stripe wire from the Tank-1 (fuel) circuit.

Quite likely that the problem started right there at the fuel tank (and probably is still there, as described above).

[lpugh]

Thanks Don and all that have tried to help
I did find 3.4 volts on this wire when disconnect from ECM. Unless I am overlooking something it should be reference voltage of about 5 volts when open ckt.
This am I took a quick look at the remote oil tank and there is a black/orange wire connected to that sensor.
I will be checking further tonight.

[Savage]

Lots of critical information was missing and later added to the original post......

[lpugh]

Found the culprit that was causing the ECM failures. Disconnected the Black/orange wire from the ECM and measured 3.4 volts on the harness side. After disconnecting every quick disconnect I could find I narrowed it down to that had been connected to the orange wire on the back of the control panel for bilge, pumps and lights. After removing it the open ckt voltage is now 5 volts as I thought it should be. Thanks for the tip Don. Kinda caught me off guard the voltage was being pulled down instead of being pulled up.
I suspect that 3.4 volts was also over loading the ckt trying to pull it up to 3.4 or more when in operation.
Rethinking history about 3 months ago during a severe rainstorm, my bilge bilges went and would not turn off. That cleared itself before I found the cause and has not happened since.
Don't know yet if it has anything to do with the severe bog when warm. I do now feel OK with replacing the PCM without ruining the replacment

[Savage]

I think a bigger question is why and when did this wire become permanently connected ? Secondly what would the technical explanation be, on how a wire that was permanently connected to the wrong place, would possibly only effect performance when the ambient temperature increased, or the livewells became full?

It just would seem odd that the performance could have ever been good, if this wire was always connected to the wrong place for the entire time that you owned the boat, assuming that is that performance gets better. The PCM should have suffered damage the second that the key was turned on.