Volvo 7.4GL PHUS won't start

[lwmlsm]

7.4GL PHUS S/N4110126342
It has been about 8 months since this boat was started, but last time it ran fine. Went out this week to get it running as lake here in Texas has finally come back up where I can get it out of the boathouse. Starter motor would not run, so have found that problem and replaced the relay that sends 12V to the solenoid. Now with a new battery it cranks over very good, but still would not start. Here are the things I have done so far, but need help. Have read most of the posts I can find about starting problems and now I need help.
1) Replaced battery with brand new cranking battery.
2) Replaced relay that controls the 12V to the starter solenoid. Now cranks over good.
3) Made sure kill switch is in place.
4) Checked spark from coil and it is good (spark jumps from 1/2 inch away to ground)
5) Checked spark from spark plug. only pulled one plug, but got good spark. Plug was not wet and was not burned and still had proper gap (.035)
6) Checked coil resistance (did not remove coil wires) but primary had <25 ohms and secondary had >11,000 ohms, so think this is good. I don't have a coil tester and not sure my battery in the DVM was good enough to get real low reading. Have heard about weak coils, but don't know how to determine.
7) Checked fuel pump and disconnected fuel line from carb and when key set to crank got a good stream of fuel pumped out. Screen inline was also clean. Don't have a pressure gauge.
8) Looking down carb and moving throttle have fuel squirting into carb, so it is getting fuel.
9) Removed fuel filter/water separator and poured gas that was in filter into glass bowl, no water in fuel and looked clean. I had put stabil in the fuel, always do.

So, now I am a loss of what to do next and would appreciate any suggestions. I may be slow to respond as boat is 60 miles away at lakehouse.

 

[coolbri70]

Re: Volvo 7.4GL PHUS won't start

:welcome: to iboatsdid you verify the operation of the choke? other than that, it needs fuel/air, spark/fire, and compression, and it will run.

 

[lwmlsm]

Re: Volvo 7.4GL PHUS won't start

did you verify the operation of the choke? other than that, it needs fuel/air, spark/fire, and compression, and it will run.

Not sure how to verify the choke operation, but the flap on the carb will set after I throttle all the way and then bring back. Also, the choke lever I can push and move the choke easily. Is there something else I should do to verify the choke?

I don't have a compression tester, but seems like I have tried everything else.

 

[coolbri70]

Re: Volvo 7.4GL PHUS won't start

the choke (flap on carb) should be closed during cold start. get a compression gauge and do a compression test, if the rings are sticking in their groves, they can let compression pass into the crankcase instead of the combustion chamber.

 

[Walt T]

Re: Volvo 7.4GL PHUS won't start

Ignition timing? He's covered pretty much everything except compression. I find it hard to believe that the engine suddenly has no compression in all cylinders. It should at least try to fire. I'd probably try holding the choke flap open and cranking at wide open throttle a bit. Just to pump some air through it. I think it's flooded despite your dry plug. Only pulled one and it was probably at the very front of the engine. Take a second battery with you to the boat and jumpers so you can crank it wide open a bit. Allow the starter to cool after 20-30 seconds or so. Probably should be ready to bring throttle back just in case it starts so it doesn't throw a rod through the side of the block, through the hull, and blow a hole in the side of the dock thereby sinking dock and boat while you stand at attention at the helm smartly saluting as you go down with the ship.

 

[lwmlsm]

Re: Volvo 7.4GL PHUS won't start

Ignition timing? He's covered pretty much everything except compression. I find it hard to believe that the engine suddenly has no compression in all cylinders. It should at least try to fire. I'd probably try holding the choke flap open and cranking at wide open throttle a bit. Just to pump some air through it. I think it's flooded despite your dry plug. Only pulled one and it was probably at the very front of the engine. Take a second battery with you to the boat and jumpers so you can crank it wide open a bit. Allow the starter to cool after 20-30 seconds or so. Probably should be ready to bring throttle back just in case it starts so it doesn't throw a rod through the side of the block, through the hull, and blow a hole in the side of the dock thereby sinking dock and boat while you stand at attention at the helm smartly saluting as you go down with the ship.

Walt,
Thanks for the response, your are right I only pulled the very front plug. I don't know how to describe it but the engine will cough ? like it is trying to start, but just does not get it complete. I will try with wide open throttle with the choke flap open and crank. As for Ignition timing, don't have a timing light anymore since I got rid of my 68 GTO (lol), but I forgot to put in the things I did was take off the distributor cap to have a look inside, it was dry and clean. All the contacts around the cap looked good and the rotor seemed to have good contacts.

One question on compression testing, do you have to do this with only one plug removed at a time? and what should the compression be? I think something in the range of 120 psi or better? Is this right.

As far as standing at the helm going down with the ship, I was in the Marine Corp and only used boats (ships) as transportation, not love. Now I have a Love/Hate relationship going on with this Crownline.
Larry

 

[Walt T]

Re: Volvo 7.4GL PHUS won't start

Remove all the spark plugs while cranking. Keep them in order so that if some are fouled you know which cylinder they came out of. Watch for water spraying out of any cylinders although you would probably know by now that there is water in the oil. No harm in checking. 100 or better would enable it to run although that's low. Look at the very first 'pump' on the gauge and see how high it goes. They should all be close to the same on that first pump. Sometimes a weak cylinder will build up to a good pressure but has a weak first pump.

Hoo-Rah


De oppresso liber

 

[Walt T]

Re: Volvo 7.4GL PHUS won't start

Wait.. You got rid of a 68 GTO?

 

[lwmlsm]

Re: Volvo 7.4GL PHUS won't start

Walt, thanks for the advice. Purchased a compression tester and will get that done next time I get to the lake. I am going to disable the fuel pump while doing this test just to keep from pumping a bunch of fuel into the carb, assume this is the right thing to do.

Yeah, sold the 68 GTO, but that has been many years ago. It was just the last time I used my timing light and have no idea where it got off to. If I get it running and think I need a timing light I think I can borrow one. Will keep you updated on progress, but it may be slow as supposed to be cold this weekend and may not get to the lake.

 

[bruceb58]

Re: Volvo 7.4GL PHUS won't start

I would be pulling all the plugs and checking distributor cap for moisture and cleanliness. Wipe it all down, inside and out. Amazing how a little bit of dirt and moisture can mess up the spark.

Pour a small amount of gasoline down the carb throat as well to make sure its not a fuel issue although it sounds like it isn't. Just don't use starting fluid.

 

[lwmlsm]

Re: Volvo 7.4GL PHUS won't start

First, let me thank everyone who has made suggestions and the great help. Was able to come back to the lake this weekend and tested compression, all cylinders pumped up to 140psi, 5 were at 120psi on the first pump and 3 were at 90psi on the first pump. So concluded that compression was not my problem, since I had all the plugs out, went ahead and just put in new plugs as some did look dark and don't really know how long it had been since they were changed. Plugs were not really the problem but think they added to the overall, changed the coil as it had spark, but was not real great, so put in new coil and wala, started right up. I retested the old coil with resistance and primary was around 47 ohms and secondary was at 11K ohms, so I believe these are not bad numbers, but had read other threads that some coils were weak. So I assume after 17 years maybe the oil filled coil might have been somewhat drying up. Anyway, I am now back in business and the boat seems to start much easier than it has ever before. Thanks again for all the help.
Larry