DatsunBoy77 Posted February 20, 2003 Share Posted February 20, 2003 Last week the car ran really good. I know it is running really rich though. The other day the starter wouldnt turn fast enough so i replaced it and now it turns awsome. But.... as soon as i put in plugs and start her up se is wobbling and spitting. 10 mins later i fould all the plugs and she stalls! I pull them out and they are like all carboned up and smelling of fuel. It hasnt done this before. It it because i am not running the cold start valve on the 83 turbo motor? It didnt have problems before this. I just wanna get the car home so i can put on my new wiring harness. Thanks. Ryan 77 with an 83 turbo. Quote Link to comment Share on other sites More sharing options...
DatsunBoy77 Posted February 20, 2003 Author Share Posted February 20, 2003 Alright a coulpe more hours have work i have come up with it stalling if you bring it over 1k to 1500. The plugs seem to just instantly carbon up. I could take them up and spray them with brake cleaner and it all comes off. Now lets say all the cranking had flooded the engine and would that mix with oil and cause this. It didnt smoke really before this and now it heavily smoking a very dark color. I am stumped right now. Edit: It just hit me that the guy i got the car from said that the timing was very much retarded ( ). I am used to working on 4 cyl. NIissans. Is advanceing the timing turning it towards the firewall on the Z's (it is still using the 77 distributor). Quote Link to comment Share on other sites More sharing options...
CU Zcar Posted February 21, 2003 Share Posted February 21, 2003 Is the smoke really black, or blueish and oily-smelling? I think I understand you to be saying black, which should be from running too much fuel which matches the symptom of the fouled plugs... Could one of your injectors be stuck open? or your fuel pressure way too high? or your AFM or temperature sender connections be dirty or the sensors bad? As for the timing, I forget which way too, but if you can get a timing light you could figure it out quickly. Or, note which way the rotor turns when the engine cranks over, and turn the distributor assembly in the opposite direction to advance timing. Seems to me that with the rotor staying in the same position relative to the crank, turning the housing in the direction opposite of rotor rotation would make the rotor trigger ignition events "earlier" relative to the crank. It sounds simple enough to me but then again I'm also tired so make sure I'm not thinking backwards, and good luck! What wiring harness are you swapping in, just out of curiosity? Quote Link to comment Share on other sites More sharing options...
DatsunBoy77 Posted February 21, 2003 Author Share Posted February 21, 2003 I mean the 83 turbo wiring harness. My friend had one in it and it was incomplete so he swapped back the 77 harness which doesnt incorporate some things such as the cold start valve. Also it is every plug so i dont think it would be all the injectors fouling out. I think it is between the afm (which i cleaned before i had this problem) and the timing. I will find out tonite though. Quote Link to comment Share on other sites More sharing options...
DatsunBoy77 Posted February 21, 2003 Author Share Posted February 21, 2003 alright now i feel like a newb. I have sourced the problem to my AFM. This is the first time i have had to work on a AFM, all of my other Nissans have been MAF, so this whole adjustment thing is new to me. Is it the screw under te cover that sits sideways? If so how do you get a screwdriver in to tighten it. While it is running if i push it back it runs great and revs... but it i just let it be it cuts out as i rev it and fouls the plugs. Do i have to take it off to adjust it? I would just look in the repair manual but it is on order because the place stopped carrying them in stock. Quote Link to comment Share on other sites More sharing options...
Guest Aaron Posted February 21, 2003 Share Posted February 21, 2003 On a basically stock engine there usually is no need to adjust the AFM. However, on top of the AFM there is a plastic cover that is glued on. Use a smalll screwdriver to pry it off. There is a spring under it that you can adjust to set the tension on the flapper door inside the AFM (tighter will make the car leaner at all RPMs). If a small adjustment does not fix your problem, then your AFM is bad, or you have a bad connection between the AFM and the ecu. I have seen both cause the problems you are having. Quote Link to comment Share on other sites More sharing options...
DatsunBoy77 Posted February 21, 2003 Author Share Posted February 21, 2003 Yeah i had the cover oof playing with it but i couldnt get a screwdriver to turn that screw because hw it sits deep sideways. I was cleaning it the other day and was moving the flap manually, do you think this could have changed it? When i was playing with it then pulled out the plug they wew only half fouled. The other half looked perfect. That was because i was playing with it i hope. Adjusted back the car was able to rev up all the way so i think that is definatly were the problem is. I will get back to yall shortly if i can figure out how to turn that damn screw. Quote Link to comment Share on other sites More sharing options...
CU Zcar Posted February 21, 2003 Share Posted February 21, 2003 I just had another idea, are you running Turbo injectors? If so, it would make sense that your car is running rich, cause the '77 ECU is calibrated for much smaller injectors, i.e. Turbo injectors will flow more fuel than stock '77 injectors would given the same amount of time "open". Playing with the AFM may give you enough adjustment to make the ECU "think" it doesn't need to open the injectors as much...if you tighten the spring on the air flap, the AFM will have less deflection for the same amount of air, but the ECU will think that less air is coming in, and hence it will not open the injectors as long. If this isn't making sense let me know (bear in mind though that I've never opened up an AFM to play with it, only read about it), and if you're not running Turbo injectors with the '77 ECU just disregard this. If you do get the '83 ECU wired in, that should run Turbo injectors - and the rest of the '83's injection system - properly. Quote Link to comment Share on other sites More sharing options...
DatsunBoy77 Posted February 21, 2003 Author Share Posted February 21, 2003 I feel like a total moron. After playing around with the AFM for a while, i realized there was a connector hanging in front of it. Somehow the coolant temp sensor connector popped off. Plugged it in and now everything is gravy. But now my oil pressure is dangerously low, probably from mixing with all that extra fuel being dumped in. Just got some oil and a filter so i guess everything will be alright. Thank god. Good ting it is beautiful right now before we get hit with some crappy wheather. Thanks to you all. Ryan Quote Link to comment Share on other sites More sharing options...
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