NewZed Posted June 13, 2012 Share Posted June 13, 2012 Just browsed the posts, but it looks to me like you're running turbo injectors with an NA control system. If so, the ECU is sending NA pulse durations to high flow turbo injectors. Should lead to too much gas. Could explain the rich condition, maybe not your other problems. Unless the 84-86 Z31 swap you did was from an 84-86 turbo Z31. Quote Link to comment Share on other sites More sharing options...
bsmuwk Posted June 13, 2012 Author Share Posted June 13, 2012 The ecu is a turbo ecu from my understanding and research. The part number on the ecu is A18 619 372. Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 14, 2012 Share Posted June 14, 2012 Oh well then. I thought you might be depending on closed loop control to get the mixture right. Good luck with it. You'll probably just have to go through the tedium of doing all of the tests in the FSM. Quote Link to comment Share on other sites More sharing options...
bsmuwk Posted June 14, 2012 Author Share Posted June 14, 2012 Meh, go figure. Time to go bonkers. Lol Quote Link to comment Share on other sites More sharing options...
Wangan280 Posted June 16, 2012 Share Posted June 16, 2012 Mine JUST started doing this 2 days ago, I have no idea why. Replaced the CHTS from my other 83 N/A motor (I have an 83 Turbo in the car) which I don't know if you can do, and no luck so far. Runs VERY rich, and sputters and backfires a lot. Used to run perfect. I don't know what to do at this point. I read somewhere that it might be the O2 sensor or the connection to the ECU from the CHTS. Have you tried that? Quote Link to comment Share on other sites More sharing options...
B. Whisky Posted June 16, 2012 Share Posted June 16, 2012 Hmmm i did read a few posts of people having sh@tty connections at the ecu. I went ahead and cleaned and greased the connectors there. Quote Link to comment Share on other sites More sharing options...
bsmuwk Posted June 16, 2012 Author Share Posted June 16, 2012 Well, there's a CHTS on its way to my door. We'll see what happens. I haven't had the opportunity to do any tests, but if the sensor helps out and fixes things, I'm makin my own damn wiring harness. It's not hard so I'll have no problem doing it lol. Should give me a nice headstart. Quote Link to comment Share on other sites More sharing options...
bsmuwk Posted June 25, 2012 Author Share Posted June 25, 2012 CHTS is a no go. Car sputters and won't rev. New Cap, rotor, wires, CHTS, has 300ZX ecu, maf and chopper wheel. is there any change in the timing on the engine with the installation of the 300zx ecu? any particular sweet spot i should have it at with the 300zx ecu? i want to get this thing peppy again Quote Link to comment Share on other sites More sharing options...
ArchetypeDatsun Posted June 25, 2012 Share Posted June 25, 2012 I have the same problem once in a while for some reason mine likes the cold morning that's when it runs the best does yours do that? Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted June 25, 2012 Share Posted June 25, 2012 Unplug the 02 sensor and see if that helps. Quote Link to comment Share on other sites More sharing options...
bsmuwk Posted July 11, 2012 Author Share Posted July 11, 2012 Unplugging the O2 sensor does nothing. I've gotten a new MAF and that hasn't helped. I'm literally at a complete loss with this. Everything's new, seems like the issue surrounds itself around the ECU swap. Quote Link to comment Share on other sites More sharing options...
Heroez Posted July 14, 2012 Share Posted July 14, 2012 (edited) I don't think it's in the ecu swap. I like several other people have a similar problem, even with the stock ECU. My latest test was to swap in a known good ECU. No change. If you want to read my painful struggle, check out the thread on zcar.com called "Never Ending Problem." As for the CHTS, if you unplug that on a warm engine, you should notice a change to running crappy right away. If you would please, read my thread and look for similarities or differences. My latest thoughts on this problem that some of us have is in the harness. Let me know what you think. Edited July 14, 2012 by Heroez Quote Link to comment Share on other sites More sharing options...
NewZed Posted July 15, 2012 Share Posted July 15, 2012 (edited) CHTS is a no go. Car sputters and won't rev. New Cap, rotor, wires, CHTS, has 300ZX ecu, maf and chopper wheel. is there any change in the timing on the engine with the installation of the 300zx ecu? any particular sweet spot i should have it at with the 300zx ecu? i want to get this thing peppy again Have you measured the timing, static and when revving? The basics of what timing an engine needs don't change much with ECUs. Static/initial should be about 10 degree +/- a few, and should advance up in to the high 20s or 30s when revved up with no load. This will tell if the initial timing is right and if the ECU is controlling timing like it should, which should also tell you that the ECU is getting the right CAS signal to control injectors with. Just a simple unprecise check of whether or not the electrical components are hooked up right and working. If it checks out then you can focus on mechanical/physical stuff, like fuel pressure, injectors, valve lash, etc. Edited July 15, 2012 by NewZed Quote Link to comment Share on other sites More sharing options...
FricFrac Posted July 16, 2012 Share Posted July 16, 2012 You have to go through it step by step. The FSM should solve 99% of the problems out there as long as you go through the whole thing and verify that it's working or not. If something fails and you skip to the next section because you think close enough or it's probalby OK you're not going to be able to fix the issues. Fix that problem then move to the next item in the chapter. It's a learning curve and it can be frustrating but there is plenty of help if you get confused and the answer is probably already typed up - a simple search usually finds what you are looking for. The connectors are a major source of electrical problems on these cars often causing intermittent issues, etc. Make sure the connection is good - all the clips to hold the connector are still there. Make sure there is no corrosion in the connector on the plug or socket and that the connector isn't cracked. Make sure as well especially by the injectors that the wire isn't hardened and cracked. Don't band aid the connectors with a connector cleaner - replace the connectors with new ones otherwise you'll see the same problem again. You can clean the sensor side up with a very fine 800 grit if they are brass terminals. If not they are plated and the plating has worn through and they will oxidize very quickly causing more intermitant problems. Quote Link to comment Share on other sites More sharing options...
bsmuwk Posted August 13, 2012 Author Share Posted August 13, 2012 just out of curiosity here, will the car run like crap if its in (i'm guessing) diagnostic mode? i think the ecu screw is turned clockwise. Quote Link to comment Share on other sites More sharing options...
bsmuwk Posted August 13, 2012 Author Share Posted August 13, 2012 just as well, there seems to be a blade connection on the part of the distributor closest to the radiator. what's that for, there are no wires going to it? Quote Link to comment Share on other sites More sharing options...
bsmuwk Posted August 19, 2012 Author Share Posted August 19, 2012 opened ECU, had a burned joint on the board. resoldered, car runs. life is good. Quote Link to comment Share on other sites More sharing options...
MazerRackham Posted August 19, 2012 Share Posted August 19, 2012 opened ECU, had a burned joint on the board. resoldered, car runs. life is good. Lol. Don't you love it when everybody is like dude that's totally not the problem, and lo and behold that was the problem. Excellent job fixing it! Hope you took a picture of the problem joint so we all know what the symptoms and solutions are! Quote Link to comment Share on other sites More sharing options...
NewZed Posted August 19, 2012 Share Posted August 19, 2012 opened ECU, had a burned joint on the board. resoldered, car runs. life is good. Which one and what does "burned joint" mean? Did you have a short between two components in the ECU or an open circuit? Pass on a little good information for the next guy. Quote Link to comment Share on other sites More sharing options...
bsmuwk Posted August 21, 2012 Author Share Posted August 21, 2012 Lol. Don't you love it when everybody is like dude that's totally not the problem, and lo and behold that was the problem. Excellent job fixing it! Hope you took a picture of the problem joint so we all know what the symptoms and solutions are! It's just one of those deals I suppose. Nothing to say but, "Go Figure" lol i have a picture of the little joint. i'll put it up here as soon as i get it off of my phone. Which one and what does "burned joint" mean? Did you have a short between two components in the ECU or an open circuit? Pass on a little good information for the next guy. my definitions might be slightly skewed from the norm, but on backside of the motherboard a burnt joint between the two components was my issue. maybe a picture will suffice better than my poor descriptions. all in all, just looking for spare ecus to keep around Quote Link to comment Share on other sites More sharing options...
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