2006 Four Winns Volvo Penta 5.0gxi-g Hesitation now won't start

[alldodge]

I just went out and checked and when I read on the Pink/Green wire going into the ignition coil (point A from Muc's post above), I get 12V when the key is turned on. It goes to 0 after a few seconds at the same time that the fuel pump stops priming

The MPR should stay ON even when fuel pump goes off. The MPR is turned on by 12V coming from the Key switch purple wire. The MPR supplies power to the coil

Si I believe its a bad key switch, MPR or connection feeding it

 

[dwelleyc1]

Here is a link to a youtube video. This is me trying to start it from the key in the off position, then trying again and holding the key on after it starts/dies out.

https://youtu.be/lo9aQiLgJ0M

I went through the ignition circuit (from what I can trace w/o electrical drawings). It is good on the Ignition terminal of the key when turned ON. For some reason, all of the circuits relating to the injection system are getting 12V only for the first few seconds, then they go to 0. This includes the plugs that go to the injectors, I pulled those and checked the pink/green wire. It acts identically to the power wire going to the ignition coil: 0V when the key is off, 12V when the key is on for a couple of seconds, then 0V until the key is turned to the RUN position. Are you sure the system should have 12V the whole time that the key is ON? Would that perhaps be the ECM shutting it off after a couple of seconds for some reason?

I also pulled the ignition relay and checked both sides of the coil with the key on and off. Off, there is 12V on one side and 2.5V on the other. With the key on, the 2.5V goes to 0 and it puts a full 12V across the relay coil terminals. That would appear correct, but the same thing applies, it's only like that for a couple of seconds after the key is turned ON.

 

[muc]

First I should apologize to you. I have never ordered manuals for customers with older equipment. What I found out today is that only current product manuals are available through the normal parts channel (that's where I looked up 7746659) older product manuals are available through THE VOLVO PENTA PUBLICATION WEB SHOP. I checked there and the wiring diagrams are available for $22.00 + shipping. Very sorry I misled you. I can only hope that you can take comfort knowing that the person who taught me this today is 30 years younger than me. And took great joy showing me how little I know about ordering older manuals.

There is NO Main Power Relay on this engine. There is a fuel pump relay and a ignition relay, both of them have the ground controlled by the ECM. All voltage testing on the coil and ICM is done while cranking the engine. What your seeing across the relay coil is normal.

the ignition relay supplies power to the coil, ICM and fuel injectors.

couple of quick tests you can do.
1. key off, pull the emergency stop switch lanyard, key on ---- do you hear 3 beeps?

2. put the lanyard back on, key on, wait until fuel pumps stop, crank engine for 2 seconds and release the the key to the on position ----- do you hear the fuel pumps for a couple of seconds? I wasn't able to hear the fuel pumps in your video.

 

[dwelleyc1]

No need for any apologies, I appreciate the help.

For step 1 above, no beeps when lanyard is pulled then turn the key on.

For step 2 above, I hear the fuel pumps when the key first turns on for a couple of seconds, then I cranked for 2 seconds, then no fuel pumps.

 

[muc]

Your ECM doesn’t know that the crankshaft is rotating, is unable to process that information or you have a ignition problem.

 

[dwelleyc1]

Do you think its the crankshaft position sensor perhaps? Maybe I hit it or messed w/ it while installing the plugs?

I have a new ignition coil coming too, just for good measure.

 

[muc]

The CPS is pretty far away from the spark plugs. But it is one of the many things that might be wrong.

Mechanics call this this style of troubleshooting—— parts swapping.
It usually only works good when you have two of the same engines and you can confirm the swap.
The problems that comes up when you don’t have a second engine.
If you use quality parts from Volvo, it can be expensive and you have a slight chance of getting a brand new bad part. If you use the cheap knockoffs from Amazon or eBay you have a very good chance of getting a bad part. If you do get a bad part, you probably won’t know and now you have two things wrong.

I have pretty strong feelings about part swapping.
Because.

Lets say that your problem is the ECM, based on your symptoms it’s possible.
More then likely you will bring the boat to someone like me because you really don’t want to guess on a $2,000.00 part.
I hook up my scantool and find many many faults stored in the ECM because you have been trying all these different things to figure out the problem. I call this corrupted history. Now if there had been something stored in there that would allow me to get a quick diagnosis, it’s gone or covered up. And at this point the engine usually doesn’t run anymore, so I can’t rebuild that history and have to start from scratch. So let’s say I test the coil and the test results are close but not right on. This is common with cheap parts, they are close but not perfect and there is usually a quality reason one is $60 and one is $200. I can usually tell it’s a aftermarket part so my first instinct is to replace it, Because technically it did fail the test. Now I might have to go right down the line and do this with most of the parts you have already replaced. The bill just keeps going up. So finally I have ruled out everything else (that’s how you usually troubleshoot a ECM because there are very few tests) and I call you for the OK on an expensive ECM. The bill is now an outrageous number, your not happy, I’m not happy because I’ve had to order parts that rarely go bad (so we don’t have them in stock) and I’ve had to start and stop on this job many times which is inefficient.
All this so I can have one unhappy customer instead of the five or six happy ones I could have had with that same amount of time.

So I’m somewhat biased when it comes to parts swapping because this has happened too many times.

 

[dwelleyc1]

Yeah I agree w/ the part swapping approach being a bad one. For what its worth, the injection coil is the volvo penta part number and right around $200, but its a shot in the dark. I also have the electrical schematics on order and will be here Monday, so hopefully they will assist with some legitimate troubleshooting.

My issue is that the area that I live in has very few people who will work on an I/O and those that do are overbooked.

 

[ripjmk]

This is a long shot but the original diagnosis may be correct, the key switch. If it were me I'd use an old analog volt meter (I keep one for these times) and connect it across the ignition switch out put (purple wire normally) and ground. Watch the meter as you key on, then thru start and back to key on. If a switch is degrading you could be getting momentary switch breaks this will be noticed on an analog volt meter by a needle twitch a situation missed by a DVM. any momentary break in ignition voltage will stop the start sequence. Any twitch I'd replace the starter/ignition switch (it's not a push button is it?).
Even more of a long shot is corroded connections on the crank position sensor, its in a bad place under the front of the engine. Before replacing it try unplugging itand reconnecting it a few times then put a dab fo dielectric grease in the connector. it might be ok!

 

[muc]

While a key switch could cause this an analog volt meter is about the worst tool to use. A good DVM is a much better tool with it’s min/max setting and much faster sampling rate and reaction time.

A bad connection at the CPS is also a possibility. But the use of dielectric grease on low voltage connections (like a CPS) is highly discouraged.

 

[dwelleyc1]

I have a Fluke 85V so I will try the suggested approach using the Min/Max setting and see what it shows.

Other than checking the wires and reseating the connector, do you have any suggested checks to do on the CPS? I did remove and then replace the serpentine belt at the same time I replaced the plugs, I believe the sensor is right under that area.

Also, just to make sure this is normal, when I replaced the rotor/distributor cap, there are a few degrees of play when I put the rotor on the ditributor. As I tighten the rotor down, it would move just a bit until it was completely tight. Is there a chance to move it one way or the other enough to not allow it to start properly? Note that I did not loosen the distributor itself, just the two T15 torque screws to replace the rotor.

 

[ripjmk]

Seems everyone has their own opinion on use of dielectric grease, after finding corrosion in multiple boat connectors 10 or so years ago I have applied it all my connectors and have had no corrosion or connection issues in any. An interesting view point can be found here http://www.w8ji.com/dielectric_grease_vs_conductive_grease.htm
Under the engine close to the bilge is one place I'd definitely use it.

 

[Lou C]

What about using contact cleaner on the contacts instead? I would not put dielectric grease on the terminals per se but maybe only on the rubber gasketing that some have to keep out moisture.
I read these threads with great interest trying to learn and keep up. I'm fluent in Quadrajets & Holleys and can have a set of points in and adjusted in no time. But since my vehicles with EFI have been so reliable, I have not had to learn much about it except for the most general stuff.
to the OP you posted this up on the four wins board first, correct?

 

[muc]

I have a Fluke 85V so I will try the suggested approach using the Min/Max setting and see what it shows.

Other than checking the wires and reseating the connector, do you have any suggested checks to do on the CPS? I did remove and then replace the serpentine belt at the same time I replaced the plugs, I believe the sensor is right under that area.

Also, just to make sure this is normal, when I replaced the rotor/distributor cap, there are a few degrees of play when I put the rotor on the ditributor. As I tighten the rotor down, it would move just a bit until it was completely tight. Is there a chance to move it one way or the other enough to not allow it to start properly? Note that I did not loosen the distributor itself, just the two T15 torque screws to replace the rotor.

CKP is the crank sensor, they changed the name awhile back and I keep forgetting to use the correct name. It's tested with a scan tool, but there is one test. Resistance between pins B+C should be infinite. Replace sensor if resistance is found.

Yes, there is some play between the distributor gear and the cam gear.

 

[muc]

What about using contact cleaner on the contacts instead? I would not put dielectric grease on the terminals per se but maybe only on the rubber gasketing that some have to keep out moisture.
I read these threads with great interest trying to learn and keep up. I'm fluent in Quadrajets & Holleys and can have a set of points in and adjusted in no time. But since my vehicles with EFI have been so reliable, I have not had to learn much about it except for the most general stuff.
to the OP you posted this up on the four wins board first, correct?

Yes there is a aerosol product. Surprisingly it's called electrical contact cleaner. It's expensive and works good. And it's the only thing that should be used. And no, brake cleaner isn't the same thing.

 

[muc]

Seems everyone has their own opinion on use of dielectric grease, after finding corrosion in multiple boat connectors 10 or so years ago I have applied it all my connectors and have had no corrosion or connection issues in any. An interesting view point can be found here http://www.w8ji.com/dielectric_grease_vs_conductive_grease.htm
Under the engine close to the bilge is one place I'd definitely use it.

I agree everyone should be allowed their own opinion.
But we also can only have one fact.
The fact that Volvo Penta publishes this in their manual leads me to believe that this isn't the correct place for dielectric grease.

IMPORTANT: Do not use dielectric grease on control circuits, sensor circuits or low voltage connections. The use of dielectric grease may cause Intermittent connections that will result in engine, transmission, and/or control errors.

I try to get my info from the experts that design and build the product, instead of amateur radio operators or YouTube.

And to be honest. I also used to use it on low voltage connections and it worked great. Until one day when it caused problems. Some of us need to learn the "hard" way, some can learn from others mistakes.

 

[dwelleyc1]

Typo above, my Fluke is an 87V.

So I tried the new ignition coil/module, no difference. I changed out the plug wires as they also came in today, no difference.

Parts that I have tried: New plugs, distributor cap, rotor, plug wires, and ignition coil/module (all Volvo Penta parts or OEM per the VP manual). Still will not fire (but cranks like normal)

I bought a fuel pressure test kit today to rule that out, here is the model:

https://www.autozone.com/test-scan-...ova-fuel-injection-pressure-tester/273356_0_0

I connected the adapter fitting to the low pressure test valve, then hooked up the gauge, then turned on the key: 0psi. I then unscrewed the gauge, unscrewed the fitting and a small amount of fuel came out. I wiped it up and put the black cover back on the test valve.

I then moved to the high pressure schrader valve. This required not adapter, so I connected it directly to my gauge (screw on fitting). I then turned on the key, heard the fuel pumps prime: 0psi. Again, I unscrewed the gauge's hose from the schrader valve and a small amount of fuel came out, but not a lot.

Am I doing something wrong with this gauge or could it be that these brand new fuel pumps are really showing 0psi on the high and low sides? If so, is that a fuel delivery clue? Perhaps anti-syphon or sender? I have never dealt with either, but I suppose that could also have contributed to my original issue of hesitation and intermittent loss of power.

 

[dwelleyc1]

What about using contact cleaner on the contacts instead? I would not put dielectric grease on the terminals per se but maybe only on the rubber gasketing that some have to keep out moisture.
I read these threads with great interest trying to learn and keep up. I'm fluent in Quadrajets & Holleys and can have a set of points in and adjusted in no time. But since my vehicles with EFI have been so reliable, I have not had to learn much about it except for the most general stuff.
to the OP you posted this up on the four wins board first, correct?

Yes Lou, you pointed me to this site and a couple of folks to reach out to (thank you).

 

[muc]

Try the gauge on your car?

 

[dwelleyc1]

Good thought. I will do that as soon as I can locate the schrader valve....Man, if only there were professionals who worked on these things for a living that I could pay to fix it. The joys of living in Maine.