'78 running rich
 

my '78 280 seems to be running to rich, and the results are its running lumpy, has a serious loss of power, and isnt passing smog..

its stock FI and sat for 3 years until last year, the lumpy running only happened when it was cold but now its happening all the time... and SERIOUS, I couldnt even outrun a camry!



-Steve
http://www.geocities.com/stev240z

Re: '78 running rich
 

Check out my post on the IZCC list in reply to Mike's 280ZX running rich.

`72/`73 240Z
`81 280ZX GL
`85 300ZX Turbo
`87 Toyota Supra Turbo
`95 Mitsu 3000GT

5814-SAirFlowMeter.jpg

Re: '78 running rich
 

I just did :o)...

a friend recommended adjusting the AFM too.. I just need to find where its adjusable...

my chiltons manual doesnt help much on the FI system, it focuses more on the carbs in the earlier Zs..

-Steve
http://www.geocities.com/stev240z

Re: '78 running rich
 

I believe the AFM adjustment screw is on the Air flow meter, a small screw on the on the bottom right corner if your looking at the AFM from the driver;s side.

Joey
1976 280Z 2+2
2+2s are not ugly

Re: '78 running rich
 

You can also carefully pry off the black plastic cover, loosen the screw that holds the white gear in place, then rotate it so that it tightens/loosens the preload on the spring

`72/`73 240Z
`81 280ZX GL
`85 300ZX Turbo
`87 Toyota Supra Turbo
`95 Mitsu 3000GT

Re: '78 running rich
 

i tried loosening and tightening that screw and it made almost no difference... didnt fix the problem..

any other suggestions? im considering putting on another AFM (i have one somewhere)

-Steve
http://www.geocities.com/stev240z

Re: '78 running rich
 

adjust the air flow meter lean it out turn counterclockwise if you have a manual make sure to check the air flow is working correctily make sure you no leaking vac hoses look under the intake for the big hose off the block that connects under the intake reset valves check the 2 rear emission items on top of the intake egr valve and the one next to it last but not least it could be the cpu{computer}

Re: '78 running rich
 

hey, my 78 was running rich after I changed the fuel injector connectors. it was rough idleing and spewing black smoke, it didnt do that before. it turned out to be my temperature sensor connection. the sensor was good but the wires and connection were corroded to hell. I replaced the connector and cut the old wires a lil past the old bullet connectors and soldered it in and sealed it. It started right up and ran normal immediately. Are your plugs wet with fuel?

Re: '78 running rich
 

I have heard that its a very bad thing to tinker with the AFM also, really hard to get it right.

Re: '78 running rich
 

I agree, it is best not to mess with the air flow meter. It usually will not go out of adjustment by itself. It will go bad but there is nothing you can do about that.

When my car started running rich, I had a bad fuel pressure regulator. I replaced it and everything was fine. That is a cheap part and easy to replace. I would suggest that and also replace the oxygen sensor.

Re: '78 running rich
 

I'm also having problem with my 73 240z. Just bought it about a month ago. The car was running rough and low idles. I did a tune-up and the plugs were charred up, so i replaced the plugs and it ran fine. Car idles about 800-900rpm and runs smooth. But about 3-4days later, car is running rough and low idles again. I check the plugs and its already charred up, too! So i bought another set of plugs and threw them in and same thing happened in a couple of days.

Does anyone have an idea of whats wrong with the car or any suggestions what i should try? I dont know too much about cars and especially carbs...any suggestions will be greatly appreciated!!!

thanks...

Re: '78 running rich
 

I have an 82' 280 ZX doing the same thing, the oxygen sensor fixed the rich running black exhaust film on the rear of the car. MPG went from 19 to 27 instantly.

When Florida required emissions testing the only way this Z would pass was to unhook the oxygen sensor, pull the three hoses to the gas evaporator canister and set the idle to 900 rpm. It would pass with zero emissions, I don't know what this does, but it worked. I paid $25 for that info from a Z specialist, it's your for free. Good luck.