Two Years ago I was able to get a waiver from the State but now it's time to smog it again and you only get one waiver in CA. Haven't taken it in yet but I know the results will be no different then before tryin to fix it now before I get the obvious test failure. Nitros Oxide and Hydrocarbon Emissions are both in acceptable limits, CO Emissions however are way off the scale and nothing seems to bring it down. They say it's using too much Gas which is confirmed by the horrible Gas Mileage (even some Gas found in the Charcoal Canister that I had to replace), O2 Sensor Replaced still off the scale, Air Pump is ok, Catalytic Converter is fine, the smog shop was suggesting maybe the Carbureator. The Van has one of those Electronic Feedback monstrosities there aren't even any visible Adjusting Screws on it, it's all controlled by the EEC.

Could it possibly be the Carbureator? The Van runs fine (unless it's really cold out, then it kinda gives me fits after initial startup but then it's fine). The Choke has always been kinda screwy but it will start even in freezing weather after 4 pumps of the accelerator.

Wanna research every possiblity before I go pulling that Carb off cause it won't be an easy task - so many vacumn lines!!, cleaning EGR Valve, Fuel Filter, etc, everything... The reason I undertake this task on such an old vehicle is that it is the only way to get my brother around (he's in a wheelchair). without it we wouldn't be able to take him anywhere (doctors appointments, etc) can't afford a new wheelchair van so this is it.

Any thoughts on this would be welcome, thanks

 

It could be as simple as it needs a new float or the floats adjusted. Way back when, I remember it was not unusual to have to rebuild a carb just because the floats had a pin hole leak develop after so many years. I did not even know what I was doing at the time, and I rebuilt them on Chevys. As long as you lay it out as you disassemble it and then put it back in the same order, it is a fairly easy job. Unlike the Chevy ones where the TPS is inside the carb.

 

this is exactly what happened to my 1987 nissan sentra in like 2001-2002. it had 2 barrel electronically controlled carburator (huge, and very complicated tubing around it). The electromagnetic valve inside of carburator vent out (stuck open) and the mixture was always too reach when driving; but I was able to adjust the mixture at idle so at idle it was good. I start noticing the problem by bad smell from exchaust; later is failed the emission test under load on running drums (NJ testing procedure). Idle emission was OK. All my efforts to fix te carb (changed the valve, put the used carb) did not work deu to extreme complexity of this stupid think. ECU, O2 sensor and other systems seemed to work. New OEM carb was too expencive (~$450)
After few months I had enouth of it and ordered the extremely simple single-barrel Weber carburator with manual choke from Italy with mounting hardware ($120, plus $70 for delivery). I removed old carb, ~10 external valves, all the tubing (all this junk was like half of shopping bag). I put new carb on, adjusted idle mixture and the car was driving great. Hovewer, it failed emission again, CO was around 1.5%. I asked guys in Italy by email, they recommended to put smaller fuel jet, or bigger air venture. They send couple of air ventures to me free of charge. But what I did was the following: I drilled the air venture slightly bigger with the drill, and then was inserting the pieces of wires into it thus making sort of adjustible venture; and then went testing. I also had to restore the vacuum lines to EGR valve and air supply into exchaust manifold in order for catalitic converter to work (it need additional) oxygen to burn CO). From third or forth attempt I had it right; gas mixtures get acceptable for catalitic converter and CO dropped to 0.05% indicating it was burning in catalitic converter; and so it passed the vigorous NJ test. From that the car was working fine until I sold it in a year; new guy crashed it total before new inspection.
That was hard but good experience. If I would had to do it again, I would not mess with OEM electronically controlled carb but put older OEM mechnical carb , or aftermarket performance carb , or something like that.
den25

 

Sounds like quite an experience den25 . I don't think I can do that in this case however. If you think New Jersey is bad, California Emissions are the strictest in the country and they recently (bout 4 years ago) got even stricter. That still isn't enough however they wanna make them even tougher..

Basically you're not allowed to change any of the OEM emissions equipment on the vehicle, All the vacumn lines, etc they check all that if anything is off or missing, it fails automatically. Unfortunatley I have to keep the Electronic POS on there as much as I would like to throw it on the nearest freeway. Up until this last smog check 2 years ago it wasn't a big problem, the two years before that it passed with a little tinkering by the smog shop. This was of course before they changed all the laws again.

I'm basically pondering whether or not to attempt to rebuild it myself or have it done at a Carburetor shop, it has never been rebuilt to my knowledge so in any case it couldn't hurt. Thing is I have never in my life messed with a Carburetor (electronic or mechanical), it's about as new a frontier to me as a transmission, but something has to be done or i'm lookin at breaking the law everytime we take my brother anywhere (not able to get tags).
It makes sense that it could be the float seeing as the computer can't seem to regulate the fuel flow properly thus it's running very rich. I'm wondering though if it could just be the Electronic Choke? That thing has always been a pain of some sorts. I mean if it's not opening fully when the engine is warm then it's not mixing the fuel properly (not enough Air) and that could cause it to run rich. How hard would it be to replace the choke by itself, and could it be done with the Carb still on the engine? I really don't want to remove it and hassle with it if I don't have to.

As I said Carb's are a new field to me one i'm being forced to learn at the moment

BTW the engine is a 302, and the Carburetor is a 2 Barrel, forgot to mention that in my first post.

 

If it is a variable venture then you have a major problem the are junk and that is all the good I can say about them. I have always replaced them with standard Ford two barrel carbs.

 

He has the autolite 2150 that is computer controlled. I'd say it's probably a dirty air filter causing some of it. Have the carb rebuilt by a reputable shop in the area, that will help too.

 

emission stndarts getting more strict DOES NOT affect the vehicles already in service. The test that vehicle should pass is specific for the model year. There is just no way the 1988 model can satisty modern LEV or SULEV standats. So your 1988 van should satisfy the standarts that were in force when vehicle was manufacturing.
And yes, California was more strict then NJ in 1988, and requirement of presence of all OEM emission equipment could quite possible be applicable here. However, it was applicable in NJ as well - I had to restore the functionality of EGR and air injection for both theyr presense and to pass the emission test (it would not pass CO without catalytical converter and NOx without EGR). Hovewer, these equipment was functional with new carburator as well. The testing station guys were not checking if I got right model of carburator or not.
For your case, carburator rebuilding and adjustment is the first step. If it is your first carb, and do not want to learn on it, do not do it yourself. Otherwise, go ahead. It is not complicated, but requires time, attention, and persistance. Concentration on this job is a must. Clogged hole 0.025" diameter, wrong gasket, out-of-plane surface of the carb section can screw the whole think up and lead to 6 MPG instead of 13.
Because of the time required, and the fact that any positive result of single rebuilding is not guranteed (espetially typical for ECC carbs), shops charge a lot for this job, both for time spend and returning warranty work.
I would say, do it yourself of find handy mechanic (skilled in carbs is good) working on the side. You can give him a hevicle for a week or 2 to fix and drive, testing (real life driving) is very essential on case of carburator repair and normal shops can not do that.
den25

 

Any further developments?

 

Actually yes, I'm glad you asked

I went down and tried to smog it the other day, I dunno why it was a waste of time I knew it would fail miserably, but I thought the DMV might want the current smog data before giving me the Registration Extension. They didn't care about that I could have just paid the fee and got the extension without worrying about the smog right now, but it's just as well I did because I now have the current data to go off of.

Anyhow here is the ASM Emissions Test Results.


HC (PPM)

M1: 15 mph ( Max = 123, GP = 312, Measured = 102 )
M2: 25 mph ( Max = 95, GP = 262, Measured = 127 )
--
CO (%) (This one is the killer)

M1: 15 mph ( Max = 0.77, GP = 2.07, Measured = 4.80 )
M2: 25 mph ( Max = 0.97, GP = 2.27, Measured = 4.96 )
--
NO (PPM) (The only normal one)

M1: 15 mph ( Max = 1056, GP = 2008, Measured = 216 )
M2: 25 mph ( Max = 1061, GP = 2016, Measured = 152 )
--

For the CO to be that far off the scale i'm wondering if maybe the ignition could be weak cause theres alot of unburned gas in there. As for the HC at 25 mph I dunno what to make of that the HC's weren't a problem last time at either measurement. Catalytic Converter maybe?

Still stumped on where to proceed short of rebuilding the Carburetor but at least now i've got til June to fix it before it becomes illegal to drive it.

 

I seem to have misplaced my smog print out, when i find it in will post it. I am also having a intermitent mis fire stumbling thing..

 

the fuel/air mixture is too reach, that is why the CO is so high. 4.8% is really high for CO, the MPG gonna be 6-8mpg, not more then that. The simplest reason might be faulty fuel solenoid inside carburator sticking in "closed" position, closing air and opening gas.

There is not enouth oxygen in mixture to burn gas, that is why HC is high (HC = HydroCarbons = unburned fuel). Ignition is all right. If ignition would be "weak", the HC would be high but CO would be good. Not the case here.

NOx is good just because the mixture is too reach and does not burning hot (try to burn gas with little oxygen, the flames are dark red = low temperature; good mixture produces blue blames = hight temperature). NOx are Nitrogen Oxides, they form at high temperature in combustion chamber; usually if timing is too advanced. General rule, if engine is knocking or close to that, NOx will be too high.

First the carburator should be fixed, to get the CO reading reasonable. Do not twick the ignition/EGR yet, or even more problems may be produced.
den25.

 

Any suggestions on a good shop in the bay area to rebuild the carb? Will it fail a visual if i was to replace the carb with a new aftermarket one.
Thanks for the info, it seems not many folks no about these carbs..

 

Try Recarbco (www.recarbco.com) thats the place I'm going to send my Carb to, they quoted me a price of $299 same price as a new Carb but with that I get, Complete Remanufacturing, a good warranty, plus they'll preadjust everything for me and smog test the Carb to make sure it passes before sending it back to me. At least the Carb will be ruled out at this point.

They are located in Pittsburg and I believe they have a shop in Emeryville I dunno if thats anywhere near you. I live up in Sacramento so I have to send mine in UPS, which is gonna be tricky for me because I have to make sure it's cleaned out first, I don't need UPS panicking from seeing any fuel and not delievering it to them or back to me.

 

a carb kit for the carb is 20.99 its not worth the 299.00 to pay someone else. it also appears your cat is not up to par. I would consider replacing it. Buy the cat and pay someone to install around here they will do it for 60.00 the cat is 50.00 from summitracing.com look under catco.

 

MavJoe,

I used to work at the pittsburg location. While we did nice clean work it was not worth the 300.00 a carb we charged. We spent about 60 minutes from start to finish on each one.