Connor280ZX Posted May 19, 2015 Share Posted May 19, 2015 So I recently installed an MSA TB. I'm having some issues with the EGR and possibly the vapor valve working. As far as i know the vac advance is working Main reason is probably being that the stock TB has three ports, for the Vac advance, EGR, and vapor valve, and the MSA one has only one. So what i did to try and conteract this issue was to bypass the TVV, and run most of the lines off of a splitter. I had made one soft mount port in the aftermarket boot that i used with the MSA tb like the stock boot. I ran the Vapor line there first. However, i noticed that if i gave the engine any more than 10% throttle, i would get FULL EGR causing the engine to run like crap unless i stepped on it. I knew this because i felt the valve retract completely into the housing. It wouldn't release immediatley when i let my foot off either, causing a near-stall. I switched the EGR with the Vapor line, and now i get what appears to be no EGR, becuase i guess there wasnt enough vacuum from the boot. And i need EGR because i'm running a cat (Cali laws), and it will ping unless i have the timing at 5BTDC or lower, which rapes my top end power. I think now that the vapor line is hooked up to the splitter from the TB, it's getting too much vacuum and sucking in fuel, causing black smoke (Line was also dripping when i removed it). So, what can/should I do about this? Quote Link to comment Share on other sites More sharing options...
Connor280ZX Posted May 27, 2015 Author Share Posted May 27, 2015 Bump Quote Link to comment Share on other sites More sharing options...
NewZed Posted May 27, 2015 Share Posted May 27, 2015 Get in to the FSM and figure out which hoses need ported vacuum, which need full time vacuum, and which need switched vacuum. Then figure out where to get those vacuum sources, using tees off of the MSA TB, or making new holes. Not sure what you mean by "vapor valve", maybe the charcoal canister purge line?, but there are no vacuum hoses that should ever pull raw fuel. Could be that you've confused your hoses and you're actually looking at the FPR vacuum hose, and your FPR is damaged and leaking fuel. At the least, figure out the right names for what you're looking at. Quote Link to comment Share on other sites More sharing options...
Connor280ZX Posted May 27, 2015 Author Share Posted May 27, 2015 Yes, canister purge line is what I meant, my bad. This section in the FSM is mainly what I've been going off of. Quote Link to comment Share on other sites More sharing options...
NewZed Posted May 27, 2015 Share Posted May 27, 2015 (edited) I just browsed through that section and have to admit it's not very clear. I'd guess that "air pipe" means throttle body port, based on the diagram and port locations. So, even based on your picture, the EGR and vacuum advance lines shouldn't change at all with throttle body. They're connected to the TVV. The canister has it's own ported vacuum line. Called "vacuum signal line' in the second drawing. So it looks like you could have a T off of the MSA port, with one hose going to the top port of the TVV, and the other going to the cap on the canister. Usually the cap is labeled, and the vaccum line is a small one. You should check your old throttle body though to see why there are three ports. It may be that they all actuate at different times which would mean you won't be able to match it exactly with the MSA TB. You can usually see the ports inside the TB, by the blade, Nissan really regressed in 1982, in FSM quality. Edited May 27, 2015 by NewZed Quote Link to comment Share on other sites More sharing options...
Connor280ZX Posted May 27, 2015 Author Share Posted May 27, 2015 I just browsed through that section and have to admit it's not very clear. I'd guess that "air pipe" means throttle body port, based on the diagram and port locations. So, even based on your picture, the EGR and vacuum advance lines shouldn't change at all with throttle body. They're connected to the TVV. The canister has it's own ported vacuum line. Called "vacuum signal line' in the second drawing. So it looks like you could have a T off of the MSA port, with one hose going to the top port of the TVV, and the other going to the cap on the canister. Usually the cap is labeled, and the vaccum line is a small one. You should check your old throttle body though to see why there are three ports. It may be that they all actuate at different times which would mean you won't be able to match it exactly with the MSA TB. You can usually see the ports inside the TB, by the blade, Nissan really regressed in 1982, in FSM quality. Yeah, i've acctually swapped back to stock a few days ago just in fear that the way it was tuned and the unknown factor of the functionality of the vacuum systems would be harming my engine, it did ping a bit after all. When i looked at the stock TB's butterfly, there were three ports positioned slightly apart, and closer/further to the rotating shaft of the butterfly, so I'd say you're right about each valve getting certain vacuum at different throttle. The black smoke was maybe caused by the timing being so retarded (To compensate for no EGR), though it did look like gas dripping from the purge line when I took it off, now that i think about it more, i'm not 100% sure it was gas, maybe just a bunch of condensation. I had the TVV bypassed, and was running everything off of one splitter, instead of 3-4 splitters if I used the TVV. Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 29, 2015 Share Posted May 29, 2015 The Black Smoke was caused by high vacuum sucking raw gas into the intake! That was probably gas dripping, it can get up there with a malfunctioning diverter diaphragm or vacuum sucking hard enough to pull liquid up the line. Depending on which line it is, if you fill your tank full enough, you can have liquid fuel AT the canister or very near it, and sucking hard vacuum will siphon that right up into the intake.You won't puff black out the back on an LSeries uncatalysed until into the low 10:1 or high 9:1 AFR's... Catalyzed and lit closer to high to mid 9's but getting hot and meltin' the cat! Quote Link to comment Share on other sites More sharing options...
Connor280ZX Posted May 30, 2015 Author Share Posted May 30, 2015 At the time I had about a quarter of a tank. There was a very noticeable cloud of black smoke in my rear view mirror when I revved it. Quote Link to comment Share on other sites More sharing options...
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