Jump to content

03 twin 350's gxi-c- replaced rotor/cap/plugs-stbd NO start but has spark!


Recommended Posts

10 hours ago, SavedInChrist said:

There it is - im totally stumped! ran just fine before - did same on port motor and it re-fired back up instantly..

 

Fyi when doing a spark test I got a big thick yellow arc between screwdriver and bare block metal (about 1/2" gap)..

Plz help!

S/N: 

3869137
4012078085

Limited possibilities with prior running (i.e. compression confirmed) and spark confirmed on each wire. Wires to the correct plug, rotor position not changed, fuel, etc. Double check everything. It’s likely something simple. When I do this, I call it a da-huh moment.

Link to post
Share on other sites

I have a 5.0 gxi ce.

My engine does not start when its humid or rains.

I have done a full tuneup, wiring harness coil replacement and it just spins.

Great spark, it's getting fuel but no start.

Yes it should be simple but it isnt.

Volvo is sending a factory rep to look at it.

Link to post
Share on other sites

Hey Curt - yes checked wires 8 times.. i tested 3 - its a little tight back there - we noticed the green led light on the little black box at the rear transom was out but always on - i checked all the fuses too - nothing bad. I read somewhere the fuse boxes can develop a loose wire - 

 

We smell fuel when it primes - and it kind of tries to start but just cant. The rotors only go on one way and i obviously paid att to the angle- if I figure out the dah moment ill post! I have the diacom stuff but wont be surprised if there are no codes-

 

Maybe i jostled the fuse box while working and something came loose- as mentioned the dizzy magnet also looked rusted under the rotor - might be sth your tech wants to check as well jeffk..

 

Link to post
Share on other sites
2 hours ago, SavedInChrist said:

Hey Curt - yes checked wires 8 times.. i tested 3 - its a little tight back there - we noticed the green led light on the little black box at the rear transom was out but always on - i checked all the fuses too - nothing bad. I read somewhere the fuse boxes can develop a loose wire - 

That black box on the transom is the active corrosion prevention system. To confirm, if it has both a green and red, that’s it and has nothing to do with the failed start. If it was a fuse, or a loose wire in the fuse box, there'd be no spark, starter wouldn’t turn, fuel pump wouldn’t kick on and prime before cranking, etc. Suggest, since three wires were checked, check the other 5. When troubleshooting, it’s always best to do it each step fully so something can be ruled-in or out completely. Since you have a 5.7GXi-C, double check that the camshaft position sensor on the distributor wasn't bumped/moved. Same with the crankshaft position sensor on the engine front. If there’s spark on all 8, and the fuel module primes before cranking (like it should), and there’s compression (it ran before this work, so there is), and the correct rotor and cap was installed, it’s likely one of these two got bumped or disturbed. This won’t throw a code, but if either is unplugged or no longer seated, you’ll see this (missing parameters).

Link to post
Share on other sites
5 hours ago, Curt said:

Limited possibilities with prior running (i.e. compression confirmed) and spark confirmed on each wire. Wires to the correct plug, rotor position not changed, fuel, etc. Double check everything. It’s likely something simple. When I do this, I call it a da-huh moment.

 

16 hours ago, SavedInChrist said:

There it is - im totally stumped! ran just fine before - did same on port motor and it re-fired back up instantly..

 

Fyi when doing a spark test I got a big thick yellow arc between screwdriver and bare block metal (about 1/2" gap).. 

Plz help!

S/N: 

3869137
4012078085

If it utilizes a crab style cap, I've had them bad right out of the box. Double check firing order, and also make sure the rotor is nested properly and not installed 180 degrees off. W

Link to post
Share on other sites

hi guys thanks - yes i check the rotor direction, it only goes one way (holes and pins are offset) - i put the old ones back same issue.

 

Curt - so ive done some reading.. seems the cam sensor sits under the rotor- since i didnt rotate the dizzy body is it possible i knocked it out of alignment? Is it something I need to set and if so how?

 

I have the diacom stuff - will that help me or do i need to use it?

 

Basically how would I go about confirming the cam sensor is dialled in (assuming its possible to mis-adjust it when swapping just the rotor/cap)..

 

thanks

Link to post
Share on other sites
19 hours ago, SavedInChrist said:

i put the old ones back same issue.

This tends to point toward something got knocked or mixed up.

19 hours ago, SavedInChrist said:

since i didnt rotate the dizzy body is it possible i knocked it out of alignment? Is it something I need to set and if so how

Yes, it's possible to hit/bump it.

Nothing to "set".

-----

Suggest these steps in order:

-Before moving the ignition to start, one click before, confirm the fuel pump module kicks on and then goes off in about 5 seconds.

-When cranking, are both fuel pump motors running or are they silent?  Do they stay running for the duration of cranking?

-Confirm spark on the other 5 wires. Yep, a pain, but...

-For kicks and giggles (again), check each wire and make sure they go to the right places. Distributor to plug, ignition control module, etc. All of them. Yep, a pain, but...

-For kicks and giggles (again), make sure no other wire is hanging loose, not fully seated, not jammed crocked in the socket, no bent pins, etc. A bright LED flashlight is super helpful. Yep, a pain, but...

-Install the old distributor cap.

-Look at the camshaft position sensor and confirm it didn't move. There are usually "witness" marks/signs if disturbed or hit/bumped. While there, pull and reseat the plug.

-If you did anything at the front of the engine, confirm the crankshaft position sensor wasn't bumped, disconnected, these sorts of things.

-Diacom will help. If you own it, why not use it. Once hooked up, crank. There shouldn't be code, but hard to tell remotely because I can't see or hear what you are experiencing. Look at the parameters for each the camshaft and crankshaft position sensors. If one of them is showing blank or values that don't make sense (outside of normal), check the wiring and retest. If the same, replace the suspect sensor. Suggest Volvo Penta if it gets to this point. Aftermarket electrical stuff tends to be a bit hit and miss with Volvo Penta.

Best wishes. Please post what you find as you go. This is a very good community that is very helpful.

Link to post
Share on other sites

You mentioned a heavy, yellow spark. Yellow is a sign of a weak spark, as a healthy spark will be fine and blue. Looking at what was disturbed during the tune up, I would look hard at the high voltage lead from the coil to the distributor cap. Perhaps the coil end is corroded, and when you pulled the other end from the cab, that was enough to have it fail. As Curt said, nothing wrong with trying the old cap and even the coil wire from the other engine. Showing spark at each cylinder can fool you, as it is a lot easier to produce a spark across an air gap at atmospheric pressure. Put the same wire on a plug, and subject it to cylinder pressure, and the same circuit will seek the easiest path to ground. Cranking it over in total darkness with eyes wide open and listening carefully for the tell tale snap, snap, snap can also help to identify a path to ground.  W

Link to post
Share on other sites
1 hour ago, Wingnut said:

You mentioned a heavy, yellow spark. Yellow is a sign of a weak spark, as a healthy spark will be fine and blue.

For sure, but I took from his post he didn’t check with the plug in. Wire to screw driver. I’m thinking if he puts a plug in and checks, it’s fine. Anything else he should troubleshoot or sequence? I believe we’re all trying to help him find the issue. Best.

Link to post
Share on other sites
50 minutes ago, Curt said:

For sure, but I took from his post he didn’t check with the plug in. Wire to screw driver. I’m thinking if he puts a plug in and checks, it’s fine. Anything else he should troubleshoot or sequence? I believe we’re all trying to help him find the issue. Best.

I would go back to the old cap and rotor as you suggested, and also transfer the coil wire from the good engine.  W

Link to post
Share on other sites

hi guys thanks for the help- will try later and see what happens. I do recall retry lightly touching the magnet under the rotor as it seemed quite rusted - so just touching that could cause issues?

Ill plug the diacom in and see what comes up during cranking - ill spray a tiny bit of fresh fuel on the arrestor as a last resort - maybe the high pressure pump isnt working. We could smell a gas smell after a few tries- ill pull plugs and see- yes i did replace the old cap/rotor - same issue.

Will update with findings later - thanks all! Wasnt all that prepared - so will have the open gap spark tester as well as other diagnostic tools..

Link to post
Share on other sites
19 hours ago, SavedInChrist said:

hi guys thanks for the help- will try later and see what happens. I do recall retry lightly touching the magnet under the rotor as it seemed quite rusted - so just touching that could cause issues?

Ill plug the diacom in and see what comes up during cranking - ill spray a tiny bit of fresh fuel on the arrestor as a last resort - maybe the high pressure pump isnt working. We could smell a gas smell after a few tries- ill pull plugs and see- yes i did replace the old cap/rotor - same issue.

Will update with findings later - thanks all! Wasnt all that prepared - so will have the open gap spark tester as well as other diagnostic tools..

Thank you.

Please don’t spray fuel or starter fluid yet.

The reason I asked about the fuel pump module and whether the pumps are on when cranking is to help diagnose.

The system will not (continue to) power the pump unless it detects spark.

Knowing the answer narrows or enlarges possibilities. 

Best.

Link to post
Share on other sites
10 hours ago, Phillbo said:

The motors turn different or just the prop shafts????  I may be lame but I have never heard of a motor that counter rotates...

Counter rotation engines are very common on inboards, and easy to accomplish as it requires a different camshaft and distributor drive gear. IO's do it in the outdrive on twins.  W

Link to post
Share on other sites
5 hours ago, Wingnut said:

Counter rotation engines are very common on inboards, and easy to accomplish as it requires a different camshaft and distributor drive gear. IO's do it in the outdrive on twins.  W

Thats why I was asking....

Link to post
Share on other sites
28 minutes ago, Iggy said:

Thats why I was asking....

His is IO-Bravo, both engine standard rotation, and he did change out the wires one at a time. Dang it, I really thought you were on to something. W

Link to post
Share on other sites
1 hour ago, Wingnut said:

His is IO-Bravo, both engine standard rotation, and he did change out the wires one at a time. Dang it, I really thought you were on to something. W

Actually, Volvo Penta’s. Same as Mercury though - both engines rotate the same. Outdrives, not enough information to say. 

Link to post
Share on other sites

hi guys so update from today - went down.. after we struggled forever last time on the original parts to restart- reinstalled new stuff.. same issue - 

 

then I checked restarting without priming the system each time.. it must be flooding cos we now have the same issue intermittent - sometimes it refires no prob - other times (when turning key fully off/on -> priming - same issue), just really struggles.

When we start at WOT she runs and idles fine - which tells me the system is flooding - OR it might still be a weak ignition issue - I recorded the diacom info and shot a short video of the spark and starting issues:

See here:

 

Link to post
Share on other sites
13 minutes ago, SavedInChrist said:

hi guys so update from today - went down.. after we struggled forever last time on the original parts to restart- reinstalled new stuff.. same issue - 

 

then I checked restarting without priming the system each time.. it must be flooding cos we now have the same issue intermittent - sometimes it refires no prob - other times (when turning key fully off/on -> priming - same issue), just really struggles.

When we start at WOT she runs and idles fine - which tells me the system is flooding - OR it might still be a weak ignition issue - I recorded the diacom info and shot a short video of the spark and starting issues:

See here:

 

If I understand the last post and video, the starboard motor now starts. Before it did not. But, now it’s starting “hard”. Please confirm that I understand the situation correctly.

How are you not “priming the system each time”?

Thank you.

Link to post
Share on other sites
11 hours ago, Curt said:

If I understand the last post and video, the starboard motor now starts. Before it did not. But, now it’s starting “hard”. Please confirm that I understand the situation correctly.

How are you not “priming the system each time”?

Thank you.

Hi curt sorry to sound confusing - when you start it first time for the day thing it fires up perfectly, its after its run just a minute that the issues start. Wingman now suggests perhaps a fuel issue rather and that maybe the return line is blocked or something.. Does the ret line go to the fuel canister or the main tank? HOw would I go about checking that - let it prime and see if excess fuel comes out? Im usually unuder the impression that low psi pumps shd be 8-10 psi and hi pressure 40-50 at prime/idle/running? If i get excess pressure on the rail then possibly the return line or something?

Seems everytime it runs thru priming its worse, and sometimes it fires right up perfect - but id say 80% of the time it cranks and cranks and cranks - wanting to start but not, and when it does it idles real rough till the excess fuel clears/burns is my guess..

When we open throttle at near WOT she fires up indicating the excess fuel it being blown out - with the throttle at neutral or an inch above she just starts REAL hard and we can smell gas..

 

New entire fuel assembly (carter) installed 2 weeks back, new regulator.. 

Link to post
Share on other sites
32 minutes ago, SavedInChrist said:

New entire fuel assembly (carter) installed 2 weeks back, new regulator.. 

Thank you. I think I understand where you are.

Which regulator was replaced? The one at the fuel module or the one on the fuel rail?

Also, does the fuel module turn on and stay on when you are cranking or does it go off.

Finally, is there a high pitched whine when the engine is running?

Link to post
Share on other sites

one at the rail - however im sure the fuel assembly came with a new one - the whole section came complete with filter, pumps etc..

will be back sat for more testing- i was thinking maybe the ignition module / corrosion perhaps.. was going to pull one from the junkyard and see what makes it go away - weak spark could cause the "rich" condition imo- want to get it done this time! 

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...