VP 4.3L V6 Tune Up Question

[superpop]

Hi Folks. I just got a new timing light and am doing my first thorough tune up on my Boat. It is a 1996 Wellcraft Eclipse with the VP 4.3L GS motor. The book says it should Idle at 550 to 650 RPM's and at that idle should be at 6 Degrees BTDC. So when I set the timing to specs it is loping along pretty slow. I am setting the idle from the timing light not the tach. I have also adjusted my just rebuilt Holley Carb and put in new plugs, cap, wires and rotor. I know the compression is good at 145 - 150 per cylinder and can think of no other reason that it would not purr like a kitten. The manual did say that I had to remove a 4 wire plug from the distributor if one was there but I only have a two wire plug going in the distributor and when I unplug that it just dies so i assume that that plug is for the ignition module in the distributor. Am I missing something here on the timing light procedure. Thanks

 

[Don S]

Re: VP 4.3L V6 Tune Up Question

Did you use the required shunt to set your distributor into base timing mode? What manual are you using?

 

[superpop]

Re: VP 4.3L V6 Tune Up Question

I am using the clymer manual. I do not have this module. Is that causing me to miss adjust the timing. Any idea on where to get this shunt or is it something I can make.

 

[Don S]

Re: VP 4.3L V6 Tune Up Question

<br /><br />Without the shunt, you can't set the timing. Its nothing more than a plug that jumpers 2 of the terminals and hooks one to positive voltage to stop the advance from working. You can probably order one from your local Volvo dealer, they don't cost much and they make the job very easy to do.<br />Here is how they are wired if you want to try and duplicate it.<br /><br />

<br /><br />Also get yourself the proper Volvo service manuals for your engine serial number. If you have the SN, I can give you the manual numbers.

 

[superpop]

Re: VP 4.3L V6 Tune Up Question

So I built the shunt and installed it and I am not sure where to go from here. The manual says with the shunt installed it should be 5 Degrees ATDC does that mean 5 degrees after top dead center or at top dead center. when I set it at 5 Degrees after top dead center and then unpluged the shunt it was way off when I removed the shunt and rechecked the timimg. the manual says to recheck after removing the shunt and that is what I did and it showed it off. It is a brand new ignition module by the way. Any other words of advice.

 

[Don S]

Re: VP 4.3L V6 Tune Up Question

Here's a question for you.<br />If it takes a special shunt to put the distributor into base timing, why would you think that without the shunt you would get the same reading when checking the timing without the shunt and no longer in base timing?????

 

[lilmandavis]

Re: VP 4.3L V6 Tune Up Question

lol i figured that out the hard way. at least i got it timed before the outdrive came off!!

 

[superpop]

Re: VP 4.3L V6 Tune Up Question

My question was more about the ATDC vs BTDC. Can I get some clarification on that. I understand that the timing will be different when I remove the shunt

 

[Don S]

Re: VP 4.3L V6 Tune Up Question

With the shunt hooked up, you set it at 5° ATDC (After Top Dead Center). Then after you disconnect the shunt you can recheck the timing at 1000 rpm and it should show around 15° BTDC.

 

[superpop]

Re: VP 4.3L V6 Tune Up Question

So my next question is my timing light has an advance adjustment does this mean I should set my light at 5 degrees and then line up the timing marks. Sorry, I am probably asking a silly questions. or do I need to set the gun at 95 degrees and then line up the marks. Thanks