Volvo 4.3 GXI-E will not start.

[regal06]

So we have had this boat about 3 months and everything was working fine, we changed the plugs and found out that we had been running on only 5 cylinders for awhile, once that issue was corrected we were no longer hitting the 4500-4800RMPs that is recommended for our motor. It was running at about 4000RPMs

We have drained the fuel and put 20gallons of fresh gas in it, changed the oil and filter, changed the water filter separator, the spark plugs that were properly gaped. After this was done we took it for a test run and the same issue we were not hitting the rpm with all 6 cylinders firing, when I unhooked the one plug that had been unhooked the first couple of time we took it out, we were back to the correct RPM of 4800 but at the same speed of 41mph as we were with all 6 firing. After and few runs across the lake she would not fire back up.

Since then we have checked the screen in the tank no issues it was clean, we check the vacuum it seems a little low so we put a new fuel pump on it hoping this would solve the problem. Still nothing the only other thing that I can think of is the anti siphon value is bad we are going to change that Monday. I have noticed that when we crank the engine the fuel pulls up slower than I thought it should, and once we stop cranking the fuel drops down and creates an air pocket between the fuel and the water fuel separator.

Any other ideas on something like this? The engine number is 3869252.

 

[CharlieB]

Re: Volvo 4.3 GXI-E will not start.

Check the spark plug firing order against the way the wires are plugged in, you may have two wires switched.

If the firing order is correct and it continues to run better with the one wire connected I would suspect a possible leaky intake valve on that cylinder, when that cylinder fires you get a small blow-back into the intake manifold an reduce the mixture to the next cylinder, weakening its power also.

Test the engine using a cylinder leak down tester, listen and measure the leakage one cylinder at a time.

 

[regal06]

Re: Volvo 4.3 GXI-E will not start.

I have checked the firing order it is correct. motor still will not start. Are there any other ideas on why the engine will not start.

 

[CharlieB]

Re: Volvo 4.3 GXI-E will not start.

Simply re-start troubleshooting at square one.

Have you checked for spark at the spark plugs?

Have you checked fuel supply to the carb?(At the carb, do NOT assume anything, just because you may hear an electric fuel pump turn on does NOT mean that it is moving fuel).

 

[regal06]

Re: Volvo 4.3 GXI-E will not start.

Well, I started back at square one. I checked the fuel system and while trying to turn the engine over I can get fuel to squirt out when i depress the release valve on the fuel rail. I also checked the spark at the spark plug and it is getting spark but when I pulled a spark plug out it was dry. If fuel was getting through the injectors, wouldn't they be wet? So i'm assuming my problem is fuel is for some reason not getting injected into the cylinders. Anyone got an idea as why or any tests I can try to figure this out?

 

[regal06]

Re: Volvo 4.3 GXI-E will not start.

sorry posted it twice

 

[CharlieB]

Re: Volvo 4.3 GXI-E will not start.

NOT Carbed, EFI, whole 'nother ball game.

Got to find the factory service manual for the correct troubleshooting sequence.

Without the 'Book' you're done, there is NO RETURN on electrical parts, yada, yada, yada, so DO NOT ASSUME anything and DO NOT start replacing any parts without proving it wrong by the Factory Service Manual.

Don has posted links to many manuals including a few Volvo.

Does anyone remember where?

 

[regal06]

Re: Volvo 4.3 GXI-E will not start.

Just thought you might want to know what the problem ended up being. It was the idle air control valve it was stuck and was not allowing air to get in and start the engine, also was causing a rough idle at times. To figure out the problem we chocked the flap open and with a few cranks of the engine it fired up. With a new valve it started like a champs. So before you go and buy a new fuel pump you might want to check that out first it was a lot cheaper. I will let you know after this weekend if it also solved the WOT RPM being low also.