okay guys, 79 280zx. this is what i own for the past month or so i have been having problems with the fuel and air mixture. yesterday i was driving on the freeway an i could fell my car stumbling, but as soon i put my foot down the accelerate it would go away, once i was back around 3k rpms it would start stumbling again. as by stumble i mean sit at 3000 the slighty jump to 3300 rpms then it got bad to were the car shut itself off, but dramatically dropping rpms from 3500 rpm all the way down to 1k, im lost n were to start. it has not even a month old fuel pump, brand new chts, or wts, fuel pressure regulator, cleaned contacts scrapped as much of the crap out as possible. all thats really let to change is idle air/ cold start valve (which the guy i bought it from said it was bad but when i first got it last year around this time it ran fine) or my afm, thats it thats left to change out fuel air wise. i realize theres probably a thread i did what they have all said some have the same symptoms but only one not both. so imi just asking for any tips ive done prettty much everything you can besides take it to someone to waste money and tell me they dont know. so any help would be great thank you.

 

AFM is the first thing I'd suspect. If you are scraping corrosion off the connectors you'll probably want to replace them with new connectors. PMed about the repair kit. Go through the AFM rebuild as well.

Cold start valve will only affect you on cold start up.

 

i clamped my idle air control valve and it started up right away and ran perfect so thats my problem

 

Except the idle air valve has several routes. Did you clamp them all?

 

no but now its ding it again so the last thing to change is afm so if you or anyone that you know has one for sale for cheaper then everyone else let me know please.

 

Did you use the FSM and meter it directly to the ECU?