-
-
Re: c3 - 69 L68 not running to good !
I would check your spark, timing and fuel. Make sure you have hot fire. That includes not missfiring. Turn the lights off with it running. Timing you already touched on. 12 degrees seems like a lot of advance but I don't know your car. Fuel needs to be getting to the carb and the fuel needs to be fresh. Old fuel does not cut it. So consider how much fuel was in the tank before you filled it and how long it was sitting. If it is not more than a year old or so, I would not worry about it. The white smoke in the exhaust should clear after a short while. You mentioned it seemed like it was getting hot. That makes me wonder what you were seeing. You might fill the radiator and start the engine, watch for bubbles in the coolant. Just look and see if the coolant is low? Tri-power??? I don't know what to say about them. I have not worked on one but I suspect it needs to be right or nothing at all. I would get rid of it and find a nice single carb set-up (sorry for my 2 cents). L-88 would like it probably.
Good luck, Terry -
Re: c3 - 69 L68 not running to good !
John if this was my car I would check out the power valve of the carbs. If the power valve is ruptured, it will not idle correctly because the mixture is to rich. All it takes is a backfire to ruin a power valve. I have Holleys on my 68 and 70 and test the power valve by putting a finger over the carb fuel bowl vent, if the engine dies right away I replace the power valve. Good luck.Comment
-
Re: c3 - 69 L68 not running to good !
Jim,
Thanks - does this apply to the two end carbs as well? ...or just the center carb?Comment
-
Re: c3 - 69 L68 not running to good !
I have never owned or worked on the 427 tri power Holleys,and I am not at home to check my parts books, but I would think all three would have power valves.Comment
-
only the center carb has a PV *NM*
Comment
-
Re: only the center carb has a PV
Clem - is there a way to check the PV once its removed from the carb?Comment
-
Re: only the center carb has a PV
if you do not mind the taste of gasoline just use your mouth to suck on the diaphram side to see if it holds vacuum.Comment
-
Re: only the center carb has a PV
Na... I dont mind... I need my new years shot of petro! Thanks again!Comment
-
Re: only the center carb has a PV
after you are thru wash out your mouth with some beer.Comment
-
Re: c3 - 69 L68 not running to good !
Has anyone asked him to check the distributor cap for carbon tracks?
Take the cap off and check for fine tracks on the inside between the contacts.Comment
-
Re: c3 - 69 L68 not running to good !
Al,
Thanks for responding - the cap is clear... I have been tied up with family all day and hope to dig back in tomorrow...Comment
-
Re: c3 - 69 L68 not running to good !
Have you checked to see if you may have got a tank of bad gas at the station? I have a few times and its hard to find because you never expect it. The best way is to take your fuel line loose and pumpm a little in a glass jar, wait for it to settle then see if water is on the bottom.
GrantComment
-
Re: only the center carb has a PV
Hey guys - well, as I mentioned earlier, I could not get the car started after I got it home.. but after the last attempt, I did notice the front carb was dripping fuel into the venture chambers.
So, today I pulled all three carbs off. The first thing I noticed that was not right was that the manifold has fuel pooled in the bottom of it... Lots of fuel... probably from the last few attempts to get it started... and all the dripping.
I checked the PV on the center carb and it seems fine. The float also seems good... its made of metal. I did take about a quarted turn on the screws that fasten the throttel plate to the main body.
So, I focused on the front carb because it was dripping fuel into the engine. The float also seems okay... but it not made of metal... Are these type any good? The seat also seems fine, but I guess I can't trust any of the components and should probably replace them all. The rear carb also showed no obvious signs of a bad float.
Is there anything in the metering plates that might fail to just cause it to start leaking fuel into the engine? Is this a common problem with 3x2 setups?
ThanksComment
-
Re: only the center carb has a PV
those are nitrophyl floats and the reason they are use in the end carbs is because the end carbs do not have metering bodies but metering plates. these floats have a shorter fulcrum arm so the float will clear the metering plate.,this shorter arm also does not excert as much closing pressure on the needle and seat causing leak thru. a lot of 67-69 3 X 2 carb engines were blown up because of the fuel leaking into the oil pan diluting the oil. my sugestion is to remove the .110 diameter needle and seats from the end carbs and replace them with .097 diameter needle and seats because it takes less pressure to hold them closed. also some corvette have a gas cap that lets air in but does not let the pressure in the tank come out. if you have a cap that does not allow the pressure to come out from the tank i would drill a 1/8" hole to vent the internal pressure which cause the fuel to be forced into the carbs after engine shut offComment
Comment