Datsundude123 Posted April 12, 2016 Author Report Share Posted April 12, 2016 I'm sure it's a vacuum leak but I can find any! I just found a hole in the side of the block under the manifold that goes straight into the oil pan so I plugged it and I'm pretty sure it's from the anti backfire valve Still doesn't run but it sounds like it wants to when I put gas in the carb Quote Link to comment
datzenmike Posted April 12, 2016 Report Share Posted April 12, 2016 That's the block vent. Don't plug. There should be a metal pipe for it that goes back and then around the exhaust manifold. Then a hose to the PCV valve on the intake. Find yours or get one and get this connected. Post a picture of the intake from the rear showing just below the carb.... maybe your PCV is missing. Quote Link to comment
Datsundude123 Posted April 13, 2016 Author Report Share Posted April 13, 2016 That's the block vent. Don't plug. There should be a metal pipe for it that goes back and then around the exhaust manifold. Then a hose to the PCV valve on the intake. Find yours or get one and get this connected. Post a picture of the intake from the rear showing just below the carb.... maybe your PCV is missing. Ok I'll post a few pictures in a bit but I was told that that was an anti backfire valve and I didn't need it so I just took it off but now that I know what it is doesn't it just take practicals from the inside off the motor to keep the motor clean? Quote Link to comment
datzenmike Posted April 13, 2016 Report Share Posted April 13, 2016 There will always be some 'blow by' past the rings that will include burnt and unburnt gas, carbon dioxide, carbon monoxide, water vapor and partly burnt oil. These vapors will condense when the engine cools and over time build up and contaminate the oil so that you have to change it more often. The PCV constantly draws a small amount of air from the crankcase and into the intake and runs it through the combustion process again. As vapors are removed, fresh clean air is allowed in from the air filter to replace it. The PCV helps keep the engine clean and extends the oil changes. Did you remove the PCV valve from your intake??? It's the thing on the right screwed into the intake. Quote Link to comment
DatsuNissanLove Posted April 13, 2016 Report Share Posted April 13, 2016 Where is this block vent located?..i have an l16 Quote Link to comment
datzenmike Posted April 13, 2016 Report Share Posted April 13, 2016 On the side of the block behind the exhaust manifold. The L16/18 has a pipe that stick straight out from the block. Quote Link to comment
DatsuNissanLove Posted April 13, 2016 Report Share Posted April 13, 2016 Ohh ima have to check that out.. behind though right..not under the manifold.. Quote Link to comment
datzenmike Posted April 13, 2016 Report Share Posted April 13, 2016 Looks like this without the manifolds on. Quote Link to comment
DatsuNissanLove Posted April 13, 2016 Report Share Posted April 13, 2016 Ok cool .. damn wut if mine doesnt have it?.. and i dont have one of those lawn mowers... shhiiittt!! Quote Link to comment
flatcat19 Posted April 13, 2016 Report Share Posted April 13, 2016 Is this thing running yet? Quote Link to comment
Datsundude123 Posted April 13, 2016 Author Report Share Posted April 13, 2016 The pipe isn't there anymore it's just open! Quote Link to comment
Datsundude123 Posted April 13, 2016 Author Report Share Posted April 13, 2016 Is this thing running yet? Nope! Quote Link to comment
Datsundude123 Posted April 13, 2016 Author Report Share Posted April 13, 2016 There will always be some 'blow by' past the rings that will include burnt and unburnt gas, carbon dioxide, carbon monoxide, water vapor and partly burnt oil. These vapors will condense when the engine cools and over time build up and contaminate the oil so that you have to change it more often. The PCV constantly draws a small amount of air from the crankcase and into the intake and runs it through the combustion process again. As vapors are removed, fresh clean air is allowed in from the air filter to replace it. The PCV helps keep the engine clean and extends the oil changes. Did you remove the PCV valve from your intake??? It's the thing on the right screwed into the intake. Yes I removed it! Quote Link to comment
Datsundude123 Posted April 13, 2016 Author Report Share Posted April 13, 2016 From what I know this motor should fire right up but it ain't! I feel like it has something to do with the wiring but then again it has spark and everything. Quote Link to comment
datzenmike Posted April 13, 2016 Report Share Posted April 13, 2016 Yes I removed it! It will never start with the PCV removed. There's your huge vacuum leak. 1 Quote Link to comment
banzai510(hainz) Posted April 13, 2016 Report Share Posted April 13, 2016 He might mean he remove the crank case vent pipe. Why he removed this I dont know. this thred is torture for me. this should be running by now dude take full piture of everything/ wire at the coil block intake set up ect....... Quote Link to comment
Dabsun Posted April 13, 2016 Report Share Posted April 13, 2016 I recently had horrible starting issues... I ended up getting a Weber carb because I figured it would remedy the situation.... One installed it ran better.... But not quite perfect. Turns out my points in the distributor were loose! Tightened up the inner screws and Bam... Problem solved. She fired up first crank 1 Quote Link to comment
datzenmike Posted April 13, 2016 Report Share Posted April 13, 2016 this thred is torture for me. this should be running by now I provided a picture of the PCV so hope he saw that and that that is what he took out. Has spark and fuel won't start. Big hole in intake from removing the PCV would explain everything and an easy fix.. 1 Quote Link to comment
Datsundude123 Posted April 13, 2016 Author Report Share Posted April 13, 2016 It will never start with the PCV removed. There's your huge vacuum leak. What if I blocked off the holes? Quote Link to comment
Datsundude123 Posted April 13, 2016 Author Report Share Posted April 13, 2016 He might mean he remove the crank case vent pipe. Why he removed this I dont know. this thred is torture for me. this should be running by now dude take full piture of everything/ wire at the coil block intake set up ect....... When I get to my shop I will take a bunch of pictures! Quote Link to comment
hobospyder Posted April 13, 2016 Report Share Posted April 13, 2016 What if I blocked off the holes? Mike wrote out a huge post on the last page on why you want the pcv valve there. Reread the last page, don't block holes pcv required Quote Link to comment
Datsundude123 Posted April 13, 2016 Author Report Share Posted April 13, 2016 Mike wrote out a huge post on the last page on why you want the pcv valve there. Reread the last page, don't block holes pcv required Ok well I'll need to go pull the pcv off of a l16 at the wrecking yard! I guess that's the reason it won't start. Quote Link to comment
Datsundude123 Posted April 13, 2016 Author Report Share Posted April 13, 2016 Can someone post a picture off the pcv valve please!! Quote Link to comment
Dabsun Posted April 13, 2016 Report Share Posted April 13, 2016 [quote name="datzenmike" post="1372602" Did you remove the PCV valve from your intake??? It's the thing on the right screwed into the intake. Quote Link to comment
Datsundude123 Posted April 13, 2016 Author Report Share Posted April 13, 2016 [quote name="datzenmike" post="1372602" Did you remove the PCV valve from your intake??? It's the thing on the right screwed into the intake. Yes I did! I'll put it back on when I find my old one or get a new one Quote Link to comment
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