Emissions and carb question

[p11g20t]

well i just picked up a 78 200sx with the l20b. i dont know a whole lot about carb'd motors, i have worked mostly on newer stuff until now, my main carb experience is on lawnmowers... =p

 

the guy i bought this from was not the brightest, he was young, and decided to rebuild the carb and try removing the emissions stuff from the engine. half of it is off the car, he cut the air rail off at all 4 tubes, and rebuilt (i think) the carb. although im not positive its all there.

my best bet on that is getting a manual and redoing it.

 

ive had mixed answers about smog stuff -- this car literally has more smog stuff than engine it appears, and im not sure what is removable and what isnt, and if there is any benefit even in doing so. i stared at it for 2 hours today and got nowhere because he just took a bunch of stuff off and left it.

so, can anyone start to even tell me how bad he messed this up? lol, and should i get the parts to put it back to stock or continue removing things? and what? =) thanks guys!

 

 

 

 

 

[Mini-L320]

Thats not that bad. U really dont need any emissions or smog crap on it unless your in California. But here a picture of my Engine Bay. Completely took of all emissions. Just make sure that you plug up everything that had a hose coming in or out off. I even had to make a plate for my intake because coolant ran threw mine.

 

I would start off with plugging up everything on that carburator first, (besides the Fuel Inlet)

Plug everything on the Intake besides the Line For the Brake Booster and other than that you should be Ay Oh Kay! :thumbup:.

[Braden]

http://community.ratsun.net/topic/24640-egr-delete-on-a-77-l20b-stock-hitachi-carb/page__p__351121__hl__%2Begr+%2Bdelete+%2B__fromsearch__1#entry351121

 

 

take eeverything off the right side of engine, replace intake, exhaust and carb. hook up vacumm advance, and brake booster. anything else gets removed. its not that bad, maybe a days worth of work if your stuff is really dirty.

[p11g20t]

great! thats a relief to hear. one mechanic i know said it wasnt possible to remove all the emissions stuff.. i found that hard to believe, but it put my doubts in me.

 

so a few things in the pics below im wondering:

 

 

1 gets plugged, 2 disappears to...?, 3/4/5 all removed?, 6/7 are on the same piece, i can unscrew it and plug it then

 

and about the items below?

 

 

im not sure where the two hoses go, and i cant figure out what the other piece is that has two wires coming from it.

 

and then theres a bunch of stuff in the forwardmost drivers side corner of the bay, is all that gone then?

 

also i have two small lines coming off my thermostat housing, one goes to #5 labeled above, the other goes to the two valve things that then connect to the intake mani below the carb

 

thanks guys!

[ggzilla]

You can remove all the emissions stuff and it will still run good. Except for the emission stuff built into the carb. But why bother, it will run good with it all hooked up. For max perf, only the air pump, EGR valve, and vaccuum hose to distributor affect the performance to a noticeble extent.

[datsunaholic]

I briefly saw your numbered hoses but for some reason they disappeared, so I have to guess which they were.

 

The long looped hose was bypassing the fuel pump for some reason. It's hooked up to the fuel rail, and the pump hose is disconnected. Take the long hose off and keep for spare hose, looks like someone was trying to run it off an outboard tank.

 

Follow that metal line, it goes to the fitting you marked amongst 3/4/5, by the valve cover, where the carb goes. The bog one is the fuel line, a hose goes between it and the carb. You do NOT want to remove these hardlines. They provide the recirculation for the fuel, which keeps you from overpowering the float valve in the carb and flooding the engine. If you switch to a Weber this recirc line is even more necessary.

 

The 2 small lines are ported vacuum. One feeds the EGR, through the temperature valve on the thermo housing and the vacuum "switch" with the wires. The other feeds the distributor vacuum advance- you need to keep that one. Just cap off the other when you remove the EGR stuff, if you do. I generally route the other one to the carbon canister's vacuum port, since it's not a parasitic load, and does more good than harm.

 

The larger hose in the middle of the manifold goes to that steel line that's curved next to it. That's for water heating the manifold- you want to keep that. You're in Oregon, not Albuquerque. Besides, if you disconnect it you have to plug both ends, and that line also acts as a coolant recirc that lets the engine warm up faster when the thermostat is closed.

[p11g20t]

alright well i got most stuff off i think. the egr is still connected to the EM, but when i get my air tools back from my brother i can cut the tube down low then get it off. i didnt want to take the EM off if i didnt have to because the last guy cut off the head of one of the bolts :blink:

 

anyways, the plug im holding below, where does that go?

im not sure what to do about the carb. he said he rebuilt the thing, and everywhere i look are loose screws and pins missing, i have a small box of random things that im guessing are supposed to be attached. the venturi was attached by 3 of 4 screws and had no gasket behind it even :rolleyes:

 

unless theres a carb rebuild thread walking me through it, i dont think its worth me trying to tear it down and redo it. how much and how hard is it to find a carb for this motor? and the aftermarket upgrades? im gonna do some searching now

 

 

so the plug im holding?

 

and in the top right, the part that butts up against the carb and has a small hose, should that be looped there or?

 

and lastly, the big tube to the right of the EGR, what do i do with that?

 

sorry for all the questions, working on a car with this kinda stuff is like a whole new ball game!

 

[Braden]

throw away the plug your holding, rebuilding a cabr is easy and is a good task for you to do and learn, once your done with it you will have a newfound sense of automotive knowledge, you need to find a non heat riser manifold set!

[Braden]

dude, you have a walker carb kit and whoever rebuilt your carb didnt use the new needle ansd seat, didnt use the new accelerator pump and possibly didnt replace a gasket or two!!!! wtf???? they also didnt use the anjo bolt lock ring!!!!! you have some work to do man!!!! dont worry take your time keep parts labeled and take pictures for reference, also the little measuring tool in the kit is for adjusting your float properly which probably wasnt done judging by how clean it looks!

[p11g20t]

dude, you have a walker carb kit and whoever rebuilt your carb didnt use the new needle ansd seat, didnt use the new accelerator pump and possibly didnt replace a gasket or two!!!! wtf???? they also didnt use the anjo bolt lock ring!!!!! you have some work to do man!!!! dont worry take your time keep parts labeled and take pictures for reference, also the little measuring tool in the kit is for adjusting your float properly which probably wasnt done judging by how clean it looks!

 

the accel pump was replaced, thats the old one in a bag, but yeah it appears he had no idea what he was doing.

there are no directions, and since its not assembled to start with, i have no idea what im doing. is there a walkthrough or blown up diagram or anything?

[datsunaholic]

The kits come with the instructions.

 

That push-off, that's an idle kick-up thing, I've only ever seen it on L-series cars with A/C, or was that automatics?. Seen it on non-A/C A-series cars though. The little hose is where it should be, looped straight to manifold vacuum. All the device does is keep the throttle from going all the way to idle under certain conditions.

 

That device you're holding, that's part of the EGR. Remove and cap the vacuum hose where it went. Where you're all done, you should have no open vacuum lines- either they get hooked up properly or get capped off.

 

Your bigger issue is plugging where the EGR used to be on the intake, because that's now a big open hole. The EGR pipe itself, that can be plugged, but the manifold needs a plate, and you should route the PCV somewhere. The PCV valve was attached to the now-missing EGR manifold. A flat plate with pipe threads, a 90deg fitting, and the PCV screwed into the 90 then the hose reattached is the way to go. You want the PCV hooked up, unless you prefer 1500 mile oil changes.

[p11g20t]

The kits come with the instructions.

 

That push-off, that's an idle kick-up thing, I've only ever seen it on L-series cars with A/C, or was that automatics?. Seen it on non-A/C A-series cars though. The little hose is where it should be, looped straight to manifold vacuum. All the device does is keep the throttle from going all the way to idle under certain conditions.

 

That device you're holding, that's part of the EGR. Remove and cap the vacuum hose where it went. Where you're all done, you should have no open vacuum lines- either they get hooked up properly or get capped off.

 

Your bigger issue is plugging where the EGR used to be on the intake, because that's now a big open hole. The EGR pipe itself, that can be plugged, but the manifold needs a plate, and you should route the PCV somewhere. The PCV valve was attached to the now-missing EGR manifold. A flat plate with pipe threads, a 90deg fitting, and the PCV screwed into the 90 then the hose reattached is the way to go. You want the PCV hooked up, unless you prefer 1500 mile oil changes.

 

ah i will ask him for the instructions on the rebuild... if he doesnt have them would anyone here? or maybe the company would replace them.

and this is a manual, it used to have AC. if anyone wants it i have the belt and compressor still he pulled off. i think it worked... have to test it.

 

i knew id have to make a plate, although not sure quite yet how i will go about it. as far as the PCV, would the below be adequate, and it needs to connect to the tube next to the EGR correct? this is the only place it will fit in

 

 

please, dont mind the previous previous owners glitter job on the VC... lol

[deadmonkey]

PCV does not go there, but I really don't know if that will work or not to be honest.

The silvery hose that comes from the engine vent tube (around behind the intake) plugs onto the PCV valve like you show in #4 post. Don't plug that up, it vents fumes from inside the engine.

 

Looking at post #12 it looks like you(or previous owner) broke off the EGR part? Because that is a compression fitting and one side should be in the piece that was bolted to the intake manifold.

 

Basically, the EGR is closed until the air in the air filter area warms up, triggers a switch and lets the vacuum open the EGR valve to suck any unburnt fuel from the exhaust. Ratsun folks usually rip that stuff out. Though mine is out now, I hope to hook it all back up someday. The PCV is the most important though. Crankcase and valve cover. Some say if there is no blow back from the valve cover, don't worry about it. Mine has a lil filter on it to keep stuff from getting in. Eventually I'll port that back into my weber filter (there is a hole on the bottom for it).

 

great! thats a relief to hear. one mechanic i know said it wasnt possible to remove all the emissions stuff.. i found that hard to believe, but it put my doubts in me.

 

so a few things in the pics below im wondering:

 

 

1/2 are coolant return (comes threw the intake to warm up the air/fuel mixture. wraps around the front (taps off and hooks where the thermostat housing is) and hooks up next to the lower coolant hose.

 

3 is the fuel line. It hooks to a 'T' and one line is from the fuel pump, one line is the fuel return. It wraps around the valve cover. 1 hose is from the fuel pump on one side(close to engine) and one line from the fuel filter to the fuel pump (away from engine)

4 is the vacuum advance for the distributor

(one hose from carb to there) the other end of the tube has a 'T'.

One goes to the charcoal filter, one goes to the timing advance on the dizzy.

5 I don't know since the rest of my stuff is off but I believe on the stock carbs there is another vacuum port for #5

The other end goes to an EGR control valve which opens/closes the EGR valve

EGR control valve jobber has a 90deg hookup, pointing right at the EGR valve.

 

6/7 are another vacuum line. Mine are currently capped because I don't have all my Emissions stuff back on yet.

[p11g20t]

i know the pcv valve doesnt go there originally. but the section it originally on is removed and will be covered up with a plate, so theres no where else to put it. i will run a section connecting it to the vent too.

 

i think at this point theres not much left to do except capping stuff off and figuring out the carb rebuild. hes looking for the instructions, otherwise i may be stuck

 

oh and yeah, in the process of trying to remove the egr, it cracked. i couldnt believe how stuck it was. a several foot breaker bar did the trick (well, sort of... it broke instead... ha) but since its coming off, no worries

[deadmonkey]

What ever you do, don't block that engine vent tube!

If you leave it open stuff may get in which is bad, and if you don't vent back to the intake somehow it will smell all sorts of nasty. Must have that PCV valve to keep it one way!

 

I'm sure if you ask around, somebody will have an extra part. They get pulled off all the time.

[p11g20t]

extra part of what?

[deadmonkey]

extra part of what?

The piece that was broke... donno its name.

[p11g20t]

That's part of the egr which is coming off anyways so i dont need it..

[p11g20t]

so in other photos it appears these dont even need to be capped off? doesnt make much sense unless theres a one way valve inside that plugs them off.

 

[datsunaholic]

The thing you have circled- it's a thermal switch. Had 2 vacuum lines (on in, one out). All it's doing now is plugging the hole, coolant doesn't go out the vacuum lines. Generally I take 'em out and put a mechanical temperature gauge in there, since you can get adapters for that thread.

[p11g20t]

Well I got her up and running today for a bit. It ran well a few times around the block but then started sputtering like it was out of gas and died. I thought it was so I put a little in and drove it a few blocks home but I had to give it gas it would rev up then down and when it would go down I'd has to put in the clutch so it wouldn't die then do it again. I was basically dancing back and forth between gas and clutch all the way home. Basically If I gave it gas it would rev up then back out like it was out of gas and want to die. Not sure the issue there. Seems like not enough fuel or maybe too much? It ran great for a bit though. Nothing on the carb has been adjusted since it came off the old pickup truck. Something seem obvious?

[LenRobertson]

Heading out the door to work, but a quick idea - when it starts acting weird, turn the engine off and look at the glass window on the side of the carb float chamber (probably have to remove the air cleaner). If gas isn't at the level of the white mark on the glass, it is starving for fuel (way below the mark or maybe even empty chamber), or way above the mark (probably from float needle sticking open). If you have trouble seeing the gas through the window, rock the car with your leg to move the gas around in the float chamber. When the gas is sloshing around a little it is easier to see. If the gas level seems fine, watch it at idle to be sure it is staying there. Then we will try another idea or two.

 

Len

[p11g20t]

I managed to adjust the needle in a little above the vac advance lines on the Pass side of the carb and it started idling and accelerating prett well! Outside she's in good condition but the interior is bad, the wiring is a complete mess as well, the gauges don't really work accurately and there are wires all over. Its got a ghetto push button start, and a toggle switch for the turn signals, and a (aftermarket?) cruise control that I haven't tried yet. I'll get more pics up soon!

[p11g20t]

Ok so I drove it some today, it was running great then suddenly started cutting out, did it for about 5 min. Only way to drive was to tap the gas repeatedly. If I held it for more than a second it would cut out. Then as quickly as it started doing that it started running fine again for a while. I parked it, came back a few hours later and as soon as it fired up it was cutting out again. Had to drive a half hour home tapping my foot rapidly on the gas the whole way. What is going on? :/

[datsunaholic]

That sounds like classic symptoms of a clogged main jet. I've driven quite some distance to get to a safe pull-off spot like that, pulled the jet plugs and cleaned it out and it ran fine- until the next piece of debris that was in the lines did it again..