RodMoyes

OK, so my car is running INSANELY rich. Most of the things that I know of that could cause that have been replaced, but...

I have not replaced the thermotime switch, head temp sensor or coolant temp sensor.

Some of you guys like Bleach and lWW or JfairladyZ might have some ideas.

Also, this really sucks right here...

It dawned on me today for the first time that since I have owned the car, I have had a consistant problem with running rich (although now it's really bad).
I remembered out of the blue, that the AFM that is currently in my car is not FROM my car! I never even thought about it before, but I suddenly rememebered that the day after I bought it and was having trouble with it it, that I swapped in the AFM from an '83 parts car I had at the time. I meant to swap them back, but before I could... Some numb nut at my shop threw mine away.

Well, it seemed to work OK and after I did the "JfairladyZ rebuild" it fixed a lot of the problems I had with stumbling and cutting out etc... But, it still is running way too rich.

Now I don't know enough about the different years and the types of AFM's they had or how much some of the things I mentioned above will affect the mixture, but I have to do something.

Now that the exhaust is leaking into the car from the accident, it's literally poisoning me to death while I'm driving. it's so bad, that even with the t-tops off I get all jacked up from it.

Any ideas?

Rod.

jfairladyz

AFM, head temp sensor or O2 Sensor would be my first three guesses. Try tightening up the AFM tension spring. That will lean it out. Even if it's not the cause of your problem it might help make your situation a little more tolerable.

NismoPick

The only things that will make it run "insanely rich" would be the AFM or head temp sensor. Any corrosion on the head temp sensor? or maybe a bad connection? Have you adjusted the AFM spring tighter, so it runs more lean? You should be able to lean it down just by adjusting the tightness of that spring.

SHADY280

i know mine was so lean it was shooting raw fuel out the back. ive been adjusting the afm tighter one tooth at a time, then driving for half tank of fuel, then doing it again. my afm is from a diff car also, they are adjusted to the particular car, so there not a general fit in any way. id try that before a sensor, or tey testing the sensor according to the manual

lifegrddude

How's the fuel pressure? Check that to see if maybe the diaphragm in the regulator is ruptured and leaking. I think idle fuel pressure is supposed to be around 28psi with the vacuum line hooked up.

RodMoyes

It's not the FPR... It's new. My year doesn't have an o2 sensor so that ain't it But those are good ideas for sure.

The temp reading in the car is lower than it should be, but that may be from just running so damn rich, or it may be running rich because it's getting a bad temp signal... I hate this ****. Head temp sensor goes bye bye today and I'm taking the AFM apart and tweaking on it a little too... I'll update later

Rod.

PooFlinginMonke

You guys know that between 1981 and 1983 that there were many things that are different wiring wise on this car.

This is evidenced by the fact that there are at least two fuel pump "schemes" and possibly three.

One with one fuel pump relay, another with three fuel pump relays, and possibly another.

I've been mixing and matching ecus and am currently running a 1982 280zx ecu on my rear drive maxima with turbo.

It runs great but only with the same year air flow meter that matches the ecu. This might apply only to this car but it may help you.

jfairladyz

Rod the sensor the ECU gets its temp signal from is not the same sensor the temp. guage gets it's signal from.

WildmaN

Yes that is fine, but no offense. Rod has an '80 which is different than '81-'83. He has different pistons lower compression, and no o2 sensor. I just had to point that out, and make sure you knew what he had.

RodMoyes

I tweaked the AFM a little bit to lean it out, but it killed the idle. I have new head temp and coolant temp sensor coming for it. I had it hooked up to the smog machine while I was tweaking it and actually watched the mixture change on the screen... That is pretty cool.

I think when it comes down to it though, that I will need a new AFM.

Rod.

Bleach

I was gonna say FPR.... but everything else has already been suggested. I have nothing more to add.

SHADY280

where do you guys get the sensors from (coolant ones) nissan cant get any of the ones in the thermostat block, my green wire one is really picky and if the wire moves just wrong the guage quits and it runs lean, in cold mode on these cars, you get full enricment, which could be part of the rich thing

RodMoyes

Yeah, that's what I was thinking. I thought I was getting a new one today, but they screwed me. I had to put the old one back in after totally destroying it

The Nissan dealer here ordered both parts out of Los Angeles for tomorrow.

We'll see if they help.

I still think the "cold mode" thing is quite likely...

Rod.

SHADY280

mine does that when the wire desides to move a mm, then its goes to full rich and pukes liquid out the back, in traffic the car behind me gets black spray on it!!!! and its hard to wash off, believe me its on my house, my parents house and everything else behind me.