VP 4.3GL Electric Choke Question.

[cmyers_uk]

Volvo Penta 4.3GL 2001 PEFS, has the original carb which I think is a holly marine 2V carb. It has an electric choke which I dont think is working The pink wire carrying the voltage to the choke from the alternator is 7v not 12v. I have checked it at the alternator and it is definately only putting 7v out of that terminal. All other aspects of the alternator check out ok, its charging the battery nicely and volts at battery is 14+ when the engines running.

 

[Silvertip]

Re: VP 4.3GL Electric Choke Question.

It may be there is piece of resistance wire built into that circuit to limit the voltage to the choke so that may be normal. Give the throttle a stroke, start the engine and check that the linkage moves and the choke plate gradually goes full open.

 

[trog100]

Re: VP 4.3GL Electric Choke Question.

i think this one is being talked about in a thread called temp sensors..<br /><br />the electric part of an eletric choke is just a heater coil.. with a cold engine the coily spring thing kinda shrinks and turns closing the choke flap.. when u switch the ignition on power gets fed to the electric heater part which causes the coily spring thing to expand and open the choke flap after x amount of time.. about as rudimentary a device as u can imagine.. heath robinson eat your heart out.. he he<br /><br />on my choke with the ignition on a straight 12 volts gets fed to the electric part.. i would assume yours should work the same.. but as someone has said it might be intentionally dropped for some reason by a resistor.. but i doubt it<br /><br />i cant quite figure where the alternator comes into it thow..<br /><br />trog100..

 

[cmyers_uk]

Re: VP 4.3GL Electric Choke Question.

Thanks trog, I couldnt work out what the 12v was for. So its the Voltage that heats up the coil so it expands not engine temperature. <br /><br />I assumed I needed 12v only having 7v may be the cause the choke does not seem to be opening but from your explanation I can test this without starting the engine (I think my neighbour had enough with burning off all the fogging oil!). <br /><br />The alternator only comes into it because that i where Volvo decided to get their feed from. The back of the alternator 6 terminals which feed power to various things , electric choke , alarm , fuel pump relay etc

 

[cmyers_uk]

Re: VP 4.3GL Electric Choke Question.

Trog, if you get a moment try this link<br /><br /> http://www.holley.com/HiOctn/TechServ/TechInfo/P222B.html <br /><br />There is something called a heat tube so Im questioning its the 12v heating up the spring? Have a peep and let me know what you think

 

[cmyers_uk]

Re: VP 4.3GL Electric Choke Question.

It may be there is piece of resistance wire built into that circuit to limit the voltage to the choke so that may be normal. Give the throttle a stroke, start the engine and check that the linkage moves and the choke plate gradually goes full open

Upinsmoke, top marks, I have just found in the manual at the P terminal with the engine running should be 6.5 - 7.5v Therefore I need to check the choke spring next I think.

 

[Fishermark]

Re: VP 4.3GL Electric Choke Question.

The bi-metal spring which closes the choke plate needs heat to open the choke. It gets the heat either from an electric element (hence an electric choke) or from a heat tube (mechanical choke) but not both.

 

[trog100]

Re: VP 4.3GL Electric Choke Question.

i think fishermark has it correct.. <br /><br />trog100

 

[Don S]

Re: VP 4.3GL Electric Choke Question.

That P terminal is actually the AC Tap, that way it only puts power to the choke coil when the engine is running (and the alternator is charging).<br />It will take a few minutes for the choke to open after you start the engine. If it doesn't, make sure the ground wire is also connected to the choke coil. If not, it won't work.<br />Also check the choke coil with an ohm meter to see if it's open. Pull both wires off to make the test.

 

[cmyers_uk]

Re: VP 4.3GL Electric Choke Question.

Thanks Guys, Don Ive just put my meter on the two terminals on the choke and its showing 2.3K ohms. Which I assume is OK as resistance = heat. I have re-read the section in the manual and going to set it up from scratch. To aid me can you give me an idea at idle from cold how open should the plate be versus when the choke opens. <br /><br />Thanks,<br /><br />P.S Thanks to everybody I am really starting to understand whats going on and Im enjoying it.

 

[Richard Petersen]

Re: VP 4.3GL Electric Choke Question.

Don. How does the choke know how much choke is needed on the colder days. Old bi-metallic coils were dead on at any air temp, no electric.

 

[Silvertip]

Re: VP 4.3GL Electric Choke Question.

On a cold start (first of the day) and regardless how cold it is, the choke plate should be fully closed. You set this on a cold engine by rotating the coil body until the choke plate just closes. When the engine fires, a vacuum piston or diaphram should suck the plate open slightly. From that point on the heat coil takes over. The initial amount the choke opens depends on the engine but about 1/8 to 3/16 would be in the ballpark.

 

[cmyers_uk]

Re: VP 4.3GL Electric Choke Question.

Thanks Upinsmoke, At the moment my plate is open by about 1 - 1.5 cm (1/2 inch) at cold (first of day). This is because I roatated the coil body last year as at the cold start I would get wisps of black smoke from the exhaust which I thought was too much choke. So I may have over done it. I shall start from scratch and reset everything back to the settings in the manual.

 

[Don S]

Re: VP 4.3GL Electric Choke Question.

Originally posted by Richard Petersen:<br /> Don. How does the choke know how much choke is needed on the colder days. Old bi-metallic coils were dead on at any air temp, no electric.

Same with electric. If you have a cold engine, just adjust the choke till the choke plate just closes. When you start the engine, the choke will start opening as the coil warms. It has nothing to do with engine temp. If it seems like it opens too quick, just tighten the choke 1 notch. I like to set the rpm up to about a 1000rpm till the choke comes off. Keeps the engine from loading up so bad. Similar to the high idle on old cars. But boats don't have a high idle to keep them cleaned out.<br /><br />NOTE: the book usually give you a notch to set them at, but I have found this is usually way too tight for summer running on boats.

 

[Don S]

Re: VP 4.3GL Electric Choke Question.

Chris<br />There is a choke unloader adjustment on the carb. This is not for where you set the choke plate. Then adjust the choke plate like I mentioned above.

 

[cmyers_uk]

Re: VP 4.3GL Electric Choke Question.

Thanks Don, Hows this for almost understanding the choke unloader is for when its cold but the throttle is wide open. That said I dont think Id ever run WOT until the engine is warm. I think now I understand whats happened. Its so mild here when I boat I suffered no problems with cold starting from how I set the choke but its way to open.

 

[trog100]

Re: VP 4.3GL Electric Choke Question.

i run with mine disconnected (backed off) i found the auto choke improved the actual initial start up on cold days.. but made the three or four minute warm up period a pain.. <br /><br />without the choke it needs a few pumps and might not fire up first time on cold days.. but when it does it keeps running at a fast idle reliably till warmed up..<br /><br />with the choke it fires up straight away but cant just be left to warm up.. it needs several restarts.. which means i cant just walk off and leave it so to speak..<br /><br />trog100

 

[cmyers_uk]

Re: VP 4.3GL Electric Choke Question.

Trog,<br /><br />That basically is my experience. With the settings as delivered it would smoke for a few minutes after startup , seriously first trip down the river I thought FIRE. Backed the choke right off and had no problems but I want to get it set and working right as per the manual, after all that should be the best settings right?

 

[trog100]

Re: VP 4.3GL Electric Choke Question.

to be honest chris i think electric chokes like we are talking about are pretty crude devices.. in a car they work okay cos there is always the fast idle in operation.. plus u drive off straight away.. in a boat u dont have the fast idle.. i assume this is some attempt at keeping the revs down low enough to enable u to crunch your dog clutch into gear and drive off.. with the hope that by the time u slow down your engine is warmed up..<br /><br />my problem is i have to do lots of idle speed reverseing and gear changing types of manoeuvering before i can move off so i have to wait for a reliable idle before going anywhere.. which means waiting for the engine to warm up.. i just find the general proccess easier without the choke operating.. even thow it does mean the cold start pumping business.. <br /><br />trog100<br /><br />ps.. my best setting is to back the thing off so it dosnt work at all.. i think some volvo engines come without a choke off any kind as well.. so i am not entirely alone in my thoughts..<br /><br />ps.. 2.. folks used to hate the things (auto chokes) in cars as well there used to be quite a little industry selling manual conversion kits..

 

[Don S]

Re: VP 4.3GL Electric Choke Question.

Sorry Chris, I was in a hurry and didn't give you the information I was planning on. It's not the choke unloader I wanted to tell you about, but the choke vacuum break (Well, that's what I call it) Volvo calls it the Choke Vacuum Qualification in the manual, and it's the adjustment that opens the choke plate a little bit to keep it from completely closing the choke and flooding the engine till it dies, once the engine is started.