Cruzn620 Posted October 29, 2007 Report Share Posted October 29, 2007 alright, clear hose coming off of my vacuum controller on my dizzy...where does that thing plug into? here's a pic.... Quote Link to comment
tnip Posted October 29, 2007 Report Share Posted October 29, 2007 a vacuum port on your carb i would think. it's for the vacuum advance right? Quote Link to comment
vindats1 Posted October 29, 2007 Report Share Posted October 29, 2007 sounds right to me too...get some nice new vacuum line first. Quote Link to comment
kiznook Posted October 29, 2007 Report Share Posted October 29, 2007 what they said ^^ Quote Link to comment
mklotz70 Posted October 29, 2007 Report Share Posted October 29, 2007 It will be the port on the base of the carb that has no vac at idle and lots of vac as the butterfly is opened. Quote Link to comment
Cruzn620 Posted October 29, 2007 Author Report Share Posted October 29, 2007 hmm...i thought i had all my ports on my carb hooked up to something. will this be on the motor side of the carb (passenger), driver side of the carb, front, rear....i'll give it a looksee next time i am down at the shop. thanks!!! Quote Link to comment
datzenmike Posted October 29, 2007 Report Share Posted October 29, 2007 On a stock L20B it would be the vacuum port to the front of the engine on the valve cover side... the other one is for EGR. Quote Link to comment
SHADY280 Posted October 29, 2007 Report Share Posted October 29, 2007 thats the dizzy breather tube. lol. you dont really need that, its for granny driving anyway, i never hook up any of my dizzy vaccum lines. Quote Link to comment
Cruzn620 Posted October 29, 2007 Author Report Share Posted October 29, 2007 ok guys, both vacuum tubes on the base of my carb (valve cover side) are hooked up. i guess 280 wins with the answer...your prize is....THANK YOU!!! and, i will probably drive my 620 like a granny! Quote Link to comment
Bleach Posted October 29, 2007 Report Share Posted October 29, 2007 I don't agree with Shady's advice on that. The timing advance gives you better cold starts and a lot more torque under any partial throttle acceleration or cruising. Especially with a 4-cyl you are going to want that. You should hook it up to the carb. Whatever your carb's port is plugged into right now is not right or there needs to be a T for both things to be plugged into it. I always plug those in on all the L-series engines I ran. It helped a lot. Quote Link to comment
datzenmike Posted October 29, 2007 Report Share Posted October 29, 2007 I don't agree with Shady's advice on that. The timing advance gives you better cold starts and a lot more torque under any partial throttle acceleration or cruising. Especially with a 4-cyl you are going to want that. You should hook it up to the carb. Whatever your carb's port is plugged into right now is not right or there needs to be a T for both things to be plugged into it. I always plug those in on all the L-series engines I ran. It helped a lot. Absolutely right to all above. If you look at your picture you can see a thermal switching valve in the thermostat housing without a hose on it. This is probably for the Feed to the PBPT valve which drives the EGR valve. Somehow some of your hoses may be hooked up wrong. When I get home I'll check my hose diagrams for you but for now the rear valve cover side port on the carb should go to the thermal switch on the thermostat housing and from it to the BPT valve. The front port on the carb should go to the vacuum advance. mike Quote Link to comment
Cruzn620 Posted October 29, 2007 Author Report Share Posted October 29, 2007 oh ok guys, thanks again for the input. there are two black hoses that were bundled in with my fuel line, and were perfect length to hook to the two tubes on the base of my carb, so i put them on there. i agree with the thermo housing ports, never had a clue on what went there. if you can scan that hose diagram and post it that would be VERY MUCH appreciated!!! when i get my manifolds back on, i will take pictures of how i have everything routed. after you guys get done laughing at me, you can tell me where everything is SUPPOSED to go...hahaha. thanks! Quote Link to comment
mklotz70 Posted October 29, 2007 Report Share Posted October 29, 2007 go download the factory manual at http://www.the620.com just above "General Datsun" is the emissions diagrams for the 620. http://www.the620.com/data/emissions_con_620.pdf Quote Link to comment
Cruzn620 Posted October 29, 2007 Author Report Share Posted October 29, 2007 thanks for the link! i looked through my manual last night and didnt see anything, but i wasn't looking through the emissions stuff. thanks! Quote Link to comment
mnementh666 Posted November 2, 2007 Report Share Posted November 2, 2007 Hey, this ties into my main question... Have an unknown year matchbox distributor, and with the replacement of the carb to a Holley, there's two available vac ports on the carb: A: manifold vacuum (ie. high vac no throttle) B: "timed spark" (ie. no vac no throttle, but picks up vac at throttle opening and loses as throttle opens farther) Which one would be best on the dist? Klotz's answer sounds like B. Thoughts? Quote Link to comment
mklotz70 Posted November 2, 2007 Report Share Posted November 2, 2007 yep....my answer is "B" :) Quote Link to comment
Jester Posted November 3, 2007 Report Share Posted November 3, 2007 I agree with Klotz. You don't want any advance at an idle. Once you start to apply gas, the vacume comes in and starts to advance the dist. Once up to speed the vacume advance does nothing and the mechanical advance takes over. Jester Quote Link to comment
datzenmike Posted November 3, 2007 Report Share Posted November 3, 2007 I agree with Klotz. You don't want any advance at an idle. Once you start to apply gas, the vacume comes in and starts to advance the dist. Once up to speed the vacume advance does nothing and the mechanical advance takes over. Jester Wow, I would have written two paragraphs to say that. Quote Link to comment
Jester Posted November 3, 2007 Report Share Posted November 3, 2007 That was just the readers digest version. Jester Quote Link to comment
datzenmike Posted November 3, 2007 Report Share Posted November 3, 2007 I'm a firm believer that there's no need to use 50 words for something when you could say the same thing with 500. :D:D:D Quote Link to comment
Jester Posted November 4, 2007 Report Share Posted November 4, 2007 Some people need 500 words to get what most would in 50. :lol: Jester Quote Link to comment
Cruzn620 Posted November 5, 2007 Author Report Share Posted November 5, 2007 oh, just for an update. i worked on the truck yesterday and found the tee that the line off the distributor connects into. it was just an oversight on my part. thanks for all the help!! Quote Link to comment
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