Delayed starting of '07 5.7L with TKS system, is this normal?

[FIRE UP]

Gents,
Brand new here. I hope this is the right place/forum to put this question out. We have an '06 Kayot V-220 with the 5.7L with TKS Mercarb 2bbl. It's equipped with the Alpha drive unit. Here's the issue with it. There seems to be an INTENSIONAL delay in the starting of the engine. In a dead cold engine, here's what happens. I turn on the key and immediately get a short "beep", followed by a muffled high pitched tone, for the total time the key is in the on position but, not cranking the engine. Now, when I turn the key to crank the engine, it will take approximately 5-8 seconds of full cranking (to me, that's a long time) before I hear another short beep and, at that very instant, I notice the oil pressure gauge pop from 0 psi to oh, around 5-10 psi. At that very instant, the engine will fire up.

it runs like a top. Smooth and for a basic carbureted 5.7L 250HP engine, it's got fair power. Now, it will do that same starting scenario, every single time I try and start it, from a dead cold position or, even when we've been boating for a while but have shut the engine down for more than 15 minutes or so. If we've only shut it down for a quick dip and then re-start it, (less than about 3 minutes of down time) the engine will fire almost right up with out the long cranking.

So, my question is, IS there some sort of oil pressure related, delayed starting system, in this era/type/smog version/make of TKS 5.7L engine. And if so, is there a way around this delayed starting system. In other words, can I by-pass something, re-wire something, so that this engine fires right up, even in a dead cold situation? I'd sure appreciate any help here. This long cranking stuff really sucks. It's hard on both the starter and the batteries.
Scott

 

[FIRE UP]

So, nobody knows anything about TKS systems huh?
Scott

 

[Fun Times]

Hi there Scott, Welcome to iboats!

So, my question is, IS there some sort of oil pressure related, delayed starting system, in this era/type/smog version/make of TKS 5.7L engine.

Yes and no. At first engine crank, the fuel pump should be getting 12v power from the Start Solenoid circuit until the oil pressure switch sees 4 PSI + of oil. Once the switch sees 4+ psi, the oil switch will take over and provide the needed 12v power to run the fuel pump. After sitting (normally a good long while) it does take a few long seconds before the engine will start up.

And if so, is there a way around this delayed starting system. In other words, can I by-pass something, re-wire something, so that this engine fires right up, even in a dead cold situation? I'd sure appreciate any help here. This long cranking stuff really sucks. It's hard on both the starter and the batteries.

No that is not advisable as it being an electric fuel pump, there needs to be a full proof way to turn of the fuel pump as soon as the engine shuts off for any reason...It's a safety reason that an boat operator may forget in the event of a situation.

Below is a long copy and paste from the service manual # 41,
Turn Key Start: Theory of Operation
The TKS system has been added to carbureted engines to:
? Provide additional fuel to air mixture when starting a cold engine. Idle speed is slightly
increased by supplying the additional fuel / air mixture required to start a cold engine.
? Prevent enrichment when starting a warm engine.
COMPONENTS
1. The TKS carburetor casting allows starting fuel to be drawn from the float bowl and
mixed with air in a chamber. This enriched mixture is drawn into the engine through an
opening in the carburetor body below the throttle plate.
2. The TKS module mounted to the carburetor. When 12V DC is applied, the TKS module
will warm internally, causing a plunger to extend from the module and close the
enrichment fuel air passage in the TKS carburetor.
3. On 3.0L engines, an oil pressure switchprovides a ground (-) path for the TKS module.
Positive (+) voltage is continuously supplied through a 20 amp fuse directly from the
engine circuit breaker.
4. On V-6 and V-8 engines an existing oil pressure switch provides 12V positive (+)
voltage to the TKS module. Ground for the TKS module is continuously supplied.
TKS SYSTEM OPERATION
The TKS Carburetor assembly provides precise fuel and air delivery during startup for all
temperature conditions. An electrothermal valve, the TKS module, is installed on the
carburetor assembly.
Before startup and according to ambient temperature, the TKS Module brass sleeve
retracts, and the enrichment fuel and air valve is opened.
The TKS fuel / air passage is normally open, allowing fuel enrichment mixture through the
carburetor continuously, unless the passage is blocked by the plunger of the TKS module.
With the key switch in the start position, the vacuum of the engine pulls the enrichment fuel
and air into the intake manifold.This starts an electrical warming of the module.
With the circuit completed, the electrothermal TKS module brass plunger extends to block
the enrichment passage.
Once the TKS module brass sleeve is fully extended, the enrichment fuel and valve are
fully closed, and enrichment stops.
In order to keep the TKS module warming and the starting channel in the carburetor closed
when engine is warm a second circuit has been added. For additional information, see the
"Typical Starting System Components" in Section 4A for your particular engine type.
TKS Starting Characteristics
On 3.0 L models - If the engine has not run for a long period of time, it might require a
couple of attempts while the fuel bowl refills. Once the engine has started, it will idle at
700-900 RPM.
On 4.3 L, 5.0 L, and 5.7L models - If the engine has not run for a long period of time, it
might require a couple of attempts while the fuel bowl refills. Once the engine is started, it
will idle around 650 to 700 RPM in idle stabilization mode. If the idle exceeds 700 RPM,
the ECM adds spark, thinking that the operator is trying to accelerate, which could cause
the engine to idle at 700-900 RPM. After the TKS module has shut off the enrichment circuit,
the carburetor will function like a standard carburetor. If the engine is out of idle stabilization
mode, (engine below 700 RPM), you will hear and feel a slight drop in RPM. After the TKS
module has shut off the enrichment passage, the carburetor will function like a standard
carburetor.
Troubleshooting
90-866202 DECEMBER 2004 Page 1C-3
NOTE: When the ambient temperature is -17 - 55? C (0?-50?F), normal engine idle should
be 650-700 RPM in idle stabilization mode.
When the ambient temperature is 10-55? C (50? - 130 ?F), normal engine idle should be
700-900 RPM and exceed the idle stabilization mode, moving into the run spark mode.
Once the enrichment circuit shuts off, the engine will idle at 650 RPM (Idle Stabilization
Mode.)
TKS Special Information
1. There will be a hissing sound for 6 to 10 minutes as the module is warming and the
enrichment channel is being closed.
2. The base gasket on the TKS carburetor is different from the old base gaskets
3. V-6 and V-8 engines use a spacer plate between the carburetor and manifold. The
gaskets have the same part number. The plastic spacer has not been changed and still
has the divider between the carburetor throats.
4. A special tool (PN 91-866201) is available to allow for adjusting the idle mixture on TKS
carburetors. The new adjustable idle mixture screw has a 16? taper and the special cap
has been C.A.R.B. approved to allow mixture adjustment only by dealers using the
special tool. The new taper will provide a finer adjustment.
Idle Mixture Adjusting Tool Part Number
9668
PN-91-866201
5. Do not make any adjustments of idle speed and/or idle mixture unless engine is
thoroughly warm and the TKS enrichment is completely shut off.
6. Generation 1 and Generation 2 carburetors function the same, and there is only a slight
difference in the location of the TKS passage within the body.
7. 3.0L engines will only have Generation 2 carburetors, while V-6 and V-8 engines will
have Generation1 and Generation 2 carburetors.
8. Refer to the parts book for proper service components.
Troubleshooting
TKS Troubleshooting
NORMAL STARTING PROCEDURE
1. Check all items listed in Operation Chart.
2. Place the remote control handle in neutral.
! CAUTION
Overheating from insufficient cooling water will cause engine and drive system damage.
Ensure that there is sufficient water always available at water inlet holes during operation.
Troubleshooting
Page 1C-4 90-866202 DECEMBER 2004
! WARNING
Explosive gasoline fumes collect in the engine compartment. Avoid injury or property
damage, operate the bilge blower for at least 5 minutes prior to starting the engine. If the
boat is not equipped with a bilge blower, open the engine hatch and leave it open while
starting the engine.
3. Turn ignition key to START. Release key when engine starts and allow switch to return
to ON position.
4. Allow engine to warm up (6-10 minutes on first start of the day). The engine will initially
idle at 650-900 RPM and then return to normal idle RPM for the engine.
Normal Engine Idle Specifications Idle in Neutral Idle in Gear
3.0 L 800 RPM 750 RPM
4.3 L, 5.0 L, and 5.7 L 650 RPM 650 RPM
5. If the engine does not start after 3 attempts:
a. Push the throttle only button and position the remote control throttle lever to the
1/4 throttle position.
b. Turn ignition key to START. Release key when engine starts and allow switch to
return to ON position.
6. If engine does not start after step 5:
a. Move the remote control throttle lever to full throttle position, then return to the 1/
4 throttle position.
b. Turn ignition key to START. Release key when engine starts and allow switch to
return to ON position.
7. Inspect the power package for fuel, oil, water and exhaust leaks.
8. To shift into gear, move control handle with a firm, quick motion forward to shift to
forward gear, or backward to shift to reverse. After shifting drive unit, advance throttle
to desired setting.
! CAUTION
Never attempt to shift unit unless engine is at idle RPM. Damage to transmission could
occur.
9. Move the remote control handle to neutral and throttle lever to idle. Allow the engine to
slow to idle speed. If engine has been operated at high speed for a long period of time,
allow the engine to cool at idle speed for 3 to 5 minutes.
10. Turn ignition key to the OFF position.
HARD START - COLD
1. If the engine does not start after third attempt, verify the following:
a. There is sufficient fuel and the fuel shut off valve is open.
b. Ignition system is functioning.
Assuming that the carburetor is the cause of the hard starting condition, the probable cause
will be that the additional fuel flow path is not functioning properly. To get the engine started:
1. Push the throttle only button.
2. Move the remote control throttle lever to full throttle position and then to the idle position.
Do this two times.
3. Place throttle at 1/4 position (throttle only)
4. Attempt to start engine again
Troubleshooting
90-866202 DECEMBER 2004 Page 1C-5
5. If engine still does not start, refer to "Engine Does Not Start."
HARD START - HOT
If the engine does not start when the engine is hot, the probable cause of hard hot-restarts
associated with the TKS carburetor will be the inadvertent opening of the additional fuel
flow path. The temperature switch was added to the system to keep power to the TKS
module to prevent the additional fuel flow path from opening during hot re-starts.
1. Check coolant temperature.
2. If the coolanttemperature is above 43? ? 3? C (110? ?8? F):
a. Verify that 12 Volts Positive (+) and ground (-) are getting to the TKS module. See
Section 4G for details.
b. Operation of the TKS module can be confirmed by placing your finger on the end
of the plastic TKS housing in the center and feeling that the electric heater is
getting warm. A warm TKS module after engine has run for 6 to 10 minutes
confirms that TKS is functioning electrically. See Section 4G for details.
3. Verify that the TKS Module is functioning normally. Follow procedure in Section 4G.
ENGINE DOES NOT START
The possible root causes of the fuel path not functioning include:
? The TKS Module failed in the closed position. See Section 4G and Section 5G.
? The fuel has varnished. See Section 5B.
? There is debris in the fuel path. See Section 5B.
? The float level is out of specification. See Section 5B.
If the engine does not start, check the following:
1. Check that float bowl is full of fuel.
2. Check that the mechanical fuel pump is working. Attach a fuel pressure gauge to the
mechanical fuel pump to verify it is working correctly.
3. Check the enrichment jet emulsion tube, TKS enrichment jet, and the main jets for
damage or debris.
ENGINE DOES NOT IDLE CORRECTLY
If the engine does not idle correctly after starting, verify that the enrichment cycle is fully
closed before adjusting checking the following:
1. The engine idle RPM has been set correctly with a warm engine.
2. Verify the timing of the engine in the base timing mode.
3. Verify there is voltage on the Packard connector attached to the TKS heater.
4. Check the enrichment jet, emulsion tube, and the main jets for damage or debris.
HISSING NOISE
There is a small enrichment air passage for the TKS system in the throat of the carburetor.
Air is drawn through this passage when TKS is in starting mode and does create a slight
whistle or hissing noise. After 6 to 10 minutes when engine has warmed and TKS system
has closed the noise will quit and will only occur again after a cold engine start. If this noise
continues after 10 minutes, this could indicate a problem with the TKS module. See Section
5B.

 

[Scott Danforth]

Welcome aboard.

 

[FIRE UP]

Funtimes,
I most certainly appreciate you're taking the time to reply on my issue. Especially posting the operational characteristics of the TKS system. Nothing bugs me more than obtaining something that's semi-complicated and, no longer in production and or, there's very little literature on it and, there's not many techs that know about it. Living here in Lake Havasu City AZ, I've only had the pleasure of dealing with one of the many companies here that service boats, engines and outdrives. And, they're not all that up on the operation of a TKS system.

You really can't analyze a problem with something until you know how it's supposed to operate correctly in the first place. So, trying to find out just how the TKS system works, has been a bit of chore. That is until you posted your answer to me on here. Again, thank you.

Now, with that being said, I'm still a bit perplexed on part of my starting issue. I know what you said and, that link said in regards to the fuel pump being supplied 12V at certain times, so it can operate. But, and this is where I'm perplexed, I already HAVE FUEL in the carburetor. I have taken the spark arrestor off the top of the carb and, on a dead cold engine, that hasn't been ran for say, a week or more, I have fuel in that carb because, I can disconnect the control cable from it and manually move the throttle plate and see the nozzles shoot fuel in each of the two bores.

IN a climate like ours, at this time, which hovers no lower than around 80-85 degrees at its lows, that would be the temp of that motor in the first startup attempt. So, my point, I'VE GOT FUEL being shot in to the intake manifold. Normally that would mean an immediate start, as long as there's NO IGNITION DELAY in getting spark to the plugs!!

You stated that, there needs to be a sure way of shutting off that fuel pump after engine shut down. Well, my question is, what's been shutting off ELECTRIC fuel pumps on millions of vehicles/trucks/motorcycles/RVs and more, for decades now, when the engine is shut down on all of those?

Another question, does each and every TKS equipped boat, all over the planet, no matter what brand/model/year/size/engine have the same exact DELAYED STARTING ISSUES that I have? If so, then obviously I'm not alone here. If not, then mine is having an issue of some sort. I now know and realize the operating principles of the TKS system but, in all of what you sent, it's not answering my issue, especially since like stated, I've already got fuel in the carb and, it's been jettisoned out of the accelerator pump nozzles, into the intake manifold. And that means to me, an instant start up. Then, in my opinion, the TKS system can do its thing.
Scott

 

[alldodge]

IS there some sort of oil pressure related, delayed starting system, in this era/type/smog version/make of TKS 5.7L engine.

Howdy Scott

No, there is not a oil pressure delay to keep the engine from starting.

The starting circuit is the same for TKS as with any other carb motor using an electric fuel pump. When the key is turned to start 12V is applied to the starter solenoid and at the same time the 12V bypasses the oil pressure switch (No 6 via Pur/Yel wire) and goes straight to the fuel pump. Once the engine starts and/or oil pressure increases about 5 psi the oil pressure switch (No 6) closes and applies 12V (via Pur wire) to the fuel pump.


I see your issue as your not getting spark and as to why it takes so long is the issue. The key that this is happening is from you mentioning that you here another beep after it has been cranking a while. My first thought is you have an issue with the key switch. I would suggest removing the switch and with a digital meter and ohm out the contacts. May take a few on/off sequences to find the issue.

 

[Fun Times]

there's very little literature on it and, there's not many techs that know about it. Living here in Lake Havasu City AZ, I've only had the pleasure of dealing with one of the many companies here that service boats, engines and outdrives. And, they're not all that up on the operation of a TKS system.

While I know there are many service shops in Lake Havasu, when it comes to Mercruiser, I've heard many times over that one of the better places that knows the mercruiser engines working systems is the guys over at Advantage boats as they service all models of boats....Next is Lakeland Marine 'especially with the Merc outboards, that's their specialty.

You really can't analyze a problem with something until you know how it's supposed to operate correctly in the first place. So, trying to find out just how the TKS system works, has been a bit of chore.

Member Just Jason was able to better explain the internal workings of the enrichment system than I in the following link, http://forums.iboats.com/forum/engin...e2#post3949270

Since you know there is fuel inside the carb waiting to be delivered to the engine, there's two tests you could try doing on your next few times out. One is right before you start heading down the ramp, turn the key to the ignition key on position only (no crank) to give the TKS heater module more time to heat up to it optimal heat range described in the Mercruiser service manual # 41 easily found free online under boatinfo....'We are not really supposed to link the manuals here anymore). Or cycling the key on, off and back on before engine crank is rumored to help.

TKS module can be confirmed by placing your finger on the end of the plastic TKS housing in the center and feeling that the electric heater is getting warm.

Now, with that being said, I'm still a bit perplexed on part of my starting issue. I know what you said and, that link said in regards to the fuel pump being supplied 12V at certain times, so it can operate. But, and this is where I'm perplexed, I already HAVE FUEL in the carburetor. I have taken the spark arrestor off the top of the carb and, on a dead cold engine, that hasn't been ran for say, a week or more, I have fuel in that carb because, I can disconnect the control cable from it and manually move the throttle plate and see the nozzles shoot fuel in each of the two bores.

Have you noticed if the engine seems to start right up (at any temp) once you pump the throttle knowing you have fuel in the fuel float bowl?

IN a climate like ours, at this time, which hovers no lower than around 80-85 degrees at its lows, that would be the temp of that motor in the first startup attempt. So, my point, I'VE GOT FUEL being shot in to the intake manifold. Normally that would mean an immediate start, as long as there's NO IGNITION DELAY in getting spark to the plugs!!

Wondering if the high ambient air temperature of Havasu usually has this time of year is negatively affecting the TKS module temp sending unit readings. :noidea:

You stated that, there needs to be a sure way of shutting off that fuel pump after engine shut down. Well, my question is, what's been shutting off ELECTRIC fuel pumps on millions of vehicles/trucks/motorcycles/RVs and more, for decades now, when the engine is shut down on all of those?

This is technically a coast guard requirement to keep the bilge area from being filled with fuel should the pump stay running or:boom: could happen.
Depending on engine model, design, etc., it would be controlled by relays, ECM's or in this case oil pressure switch.

Another question, does each and every TKS equipped boat, all over the planet, no matter what brand/model/year/size/engine have the same exact DELAYED STARTING ISSUES that I have? If so, then obviously I'm not alone here. If not, then mine is having an issue of some sort. I now know and realize the operating principles of the TKS system but, in all of what you sent, it's not answering my issue, especially since like stated, I've already got fuel in the carb and, it's been jettisoned out of the accelerator pump nozzles, into the intake manifold. And that means to me, an instant start up. Then, in my opinion, the TKS system can do its thing.

Unfortunately if you search online 'Mercruiser TKS hard starting', you will find that you are not always alone.

http://www.bing.com/search?q=mercru...+hard+starting&form=IE10TR&src=IE10TR&pc=DCJB

You may as well check to see if your TKS diode is working correctly as with the ambient air temperature you live in might be fooling the system.
TKS (Turn Key Start) carburetors. When the engine is warm ...

All that mentioned, AllDodge may be on to something as it's not normal to keep hearing beeps like you described in the first post. While at home on the garden hose, you'll want to try using both a timing light connected to the coil wire to see if you are getting a consistent flash at engine crank till started also connect a volt meter up to the + side of the coil and see if you get a consistent 12.4+ volts during cranking till started.

 

[FIRE UP]

Wow, you guys are great, no doubt about that. I will do these tests that you have suggested. And, I surely want to thank you for the link to the service manual. As far at the diode test, I already removed it and checked it for continuity in both directions. It works just like it's supposed to. So, no problem there. I thought of the same idea on putting a timing light on one of the spark plug wires and cranking a cold engine to see and make sure I was getting spark at that time. The coil wire would work better so, thanks for that. I also had not thought of the idea on checking for 12v at the coil +. I will do that too. Man, this is great. I'm bound and determined to get to the bottom of this.

Sometimes these "Coast Guard" and ultra-safe stuff can be a pain in the a.... I've had numerous boats in the past and, ALL of them have started right up. But, none of them had this TKS system. All of the info I've read so far pertains to a normally starting engine. They do mention that, if the boat has sat for a while, (no specific amount of time, i.e. maybe a month or more) that it may take a while to start.

This engine, starts the same exact way, each and every time. It has two beeps when I first turn the key to start it. One is very short and semi loud and, the other remains on, while cranking the engine but is very faint. Now, like stated, if I keep my eye on the oil pressure gauge, the micro second that gauge shows pressure, the loud beep comes back on and, the engine starts. It does it this way, every single time, on a cold engine.

As for a warm engine. It depends on just how long it's been since shut down. If we're running it and, stop to take a dip to cool off, and that takes maybe 1-2 minutes, then I go to start that engine, it fires right up with no long cranking session and, yes, the louder beep is also heard, only a lot sooner. But, if we wait longer than say, 10 minutes to re-start the engine, it does its LONG CRANKING PROCESS just like as if it were dead cold. And, the beeps, are identical, just like any other time I start it at home, in the driveway. So, in the mean time, I'll do some of these suggested tests and let all of you know what the final results are. Thanks so much for helping me here. It's so embarrassing with others near by, while I'm cranking and cranking and cranking, what appears to be a really nice boat, to get it started, EACH AND EVERY TIME IT COOLS OFF.
Scott

 

[Fun Times]

This engine, starts the same exact way, each and every time. It has two beeps when I first turn the key to start it. One is very short and semi loud and, the other remains on, while cranking the engine but is very faint. Now, like stated, if I keep my eye on the oil pressure gauge, the micro second that gauge shows pressure, the loud beep comes back on and, the engine starts. It does it this way, every single time, on a cold engine.

If you have a depth gauge, Try to make sure you're not hearing the depth gauge, sometimes depth gauges will beep at first start up as well.

With all that you mentioned, one other test you'll want to investigate is figuring out how to connect you multimeter up to the fuel pump power connecter leads because like said, you should see 12v power as soon as you start cranking which come from the solenoid before the switch takes over at 4 psi.

Let us know, good luck.