xrotaryguy

Well, I failed twice today. I was so sure that I'd pass too. Sorry for rambling on about this car. I'm just trying to get my thoughts in order about why this thing keeps failing. Kinda like thinking (read wining) out loud.

Unfortunately, I had a full tank of gas, so I was unable to add alcohol to the tank. After failing the first time, I ran the car around on the freeway until it was down about 1/3 of a tank. I added a gallon of alcohol to that and it seemed to help, but it wasn't enough. Rats.

I also adjusted the idle mixture screw to be about as lean as possible. It was so lean in fact that one of the guys at the station couldn't get it to come off idle. I think he was of above average incompetence though. I also turned the "throttle adjusting screw" in a half turn.

It's failing so miserably that I'm thinking that I need to do something with the carb. I'm hesitant to try to rebuild it because that last one of these that I tried to rebuild was warped and could not be put back together. The one that's on it now came off of one of Hidden Valley's REPUs. It was the only 13b carb there that had semi movable throttle shafts. Semi movable... that's a bad sign I guess.

Another carb possibility is to modify the intake manifold to accept an 81-85 Rx7 carb. That would probably help since these carbs: 1.) Are newer, and therefore less worn 2.) Are jetted leaner to work with catalytic converters 3.) Are considerably easier to find stock replacement parts for 4.) have a large following. The draw back it that... well, an Rx7 carb doesn't belong on an Rx4.

I wonder if it's possible to put 81-83 Jets from a Nikki carb into a 70's vintage Hitachi for a 13b. And if so, I wonder what effect that would have. It might mean changing the emulsion tubes and the air bleeds too. Shoot, some or all of these parts may be non-interchangeable.

It's also possible that this thing just needs to have the engine rebuilt. It smokes very badly upon start-up if it has been left to sit for more than a couple of weeks. The smoking continues for a good 10, maybe even 15 minutes. Once the car is warmed up though, it stops doing that and if it's driven regularly (which it isn't) then it doesn't really smoke at all.

I should probably change the plugs too.

Ok, I'm done wining.

Latin270

Oh my....Al Gore is going to hunt you down! Just give it to me! HURRY!

fluffysheap

Are you failing CO, HC, or NOx? Do you have an idle test only or a dyno test? And what year RX-4 is it? (edit: oh its a '75 from your sig, I see).

First thing you should do, is take the top off the carb and see if you can't get it a little bit cleaner. I would have done that before I put it on, if the throttle shafts didn't even move smoothly.

You shouldn't need to rejet your car to pass emissions. The factory jetting is a tad rich to cut down on NOx. But it's not so rich you can't pass. There is probably something simple you have wrong. My guess, if your air pump is working, and your carb is in proper shape, next would be timing or distributor points. Upgrade to electronic ignition and you'll run a lot better and get better emissions and gas mileage too. It's not like you need a new cat

I have no idea whether you can replace the jets with something else or not. Datsun Z guys might know since their cars used Hitachis too and there seem to be a lot more 240Zs than there are RX-4s out there nowadays.

I'm sort of surprised you have to do emissions at all since you aren't in CA - but hey I guess you do Can't you get classic/collector plates or something for it to make you exempt?

SLOASFK

iTrader: (5)

you need to move to a state that doesn't test non-OBD cars for emissions.