MaTTSuN Posted November 23, 2005 Share Posted November 23, 2005 anyone have a turbo ECU and or harnes they wanna sell? i figure thats my problem with intermitent.. problemruns good then runs like crap, and cant drive under load. stock 81 turbo with 3inch full exaust. would the O2 sensor make it like that? it was new when i put it in. im trying to get ahold of the local Z shop and get a pro on the job but he doesnt like to pick his phone up haha Quote Link to comment Share on other sites More sharing options...
Hybrid240z Posted November 23, 2005 Share Posted November 23, 2005 Check out Bastaad's comments on this post. This could be the simple solution to your problem. http://forums.hybridz.org/showthread.php?t=89131&highlight=cleaning+turbo+connectors Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 23, 2005 Share Posted November 23, 2005 Yeah, I would suspect flakey wiring before the ecu. I've seen problems with those wiring harnesses more than once, that is why I built one from scratch. Works 1000 times better now. Quote Link to comment Share on other sites More sharing options...
Guest ambersdad Posted November 23, 2005 Share Posted November 23, 2005 If it turns out that you do need an ECU - give me a call. I have an 81 ZXT Automatic that is undergoing some serious mods and I won't need it. Car ran great. No problems. Let me know. Vic Quote Link to comment Share on other sites More sharing options...
big-phil Posted November 24, 2005 Share Posted November 24, 2005 Hey thats what mine was doing turned out it was the CAS. I guess it was not sending a clear signal. I would try spraying some cleaner on it.....if its on the block that is. Quote Link to comment Share on other sites More sharing options...
MaTTSuN Posted November 24, 2005 Author Share Posted November 24, 2005 wow thanks for the replies. ive cleaned all sensors befor my post i changed senors and cleaned the ECU plugs. the light that comes on now "but has already been flickering in my head" is the CAS, Befor i put this motor in i cleaned it up and painted the thing. i had the intake and exaust off but i left the CAS on it is a 81 so it has it on the block and bottom pully. I may have sprayed some paint all over it haha would that make this problem? or would cleaning it all down sanding the paint off the pulley even matter? im not exactly sure how the CAS picks up the singnal but i would assume its with magnets or something like that. so befor i tear into it what are the odds of the engine paint messing up with my ignition signal?. thanks again guys now i have some more hope bfeor sending it off to a shop anyone have a 82-83 dizzy haha Quote Link to comment Share on other sites More sharing options...
TheNeedForZ Posted November 26, 2005 Share Posted November 26, 2005 Matt, I have a ZXT ECU, I can't sell it, but if you want to, you can plug that in and see if it solves the problem before you put money down for a new one. I live in Richmond. If interested, PM me. Quote Link to comment Share on other sites More sharing options...
MaTTSuN Posted November 26, 2005 Author Share Posted November 26, 2005 im leaning more towards the CAS being messed up i wish i could find another one 2 try or buy to see this thing burn some rubber. the shop guy siad it sounded like the AFM but i dont think thats it i guess i could try one of those 2. who knows a mega squirt would prob cost me the same in the end naybe i should go that route and forget about this old stuff. ..... but then they have won haha Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 26, 2005 Share Posted November 26, 2005 Honestly I doubt it's the CAS. I have seen this problem more than once and I've changed CAS sensors before with no positive results. Actually I doubt it is common at all for them to fail. I have found it to usually wiring related. Big Phil PM'd me last night to tell me that his car is still messed up, his problem went away after fixing the CAS but came back. Likely just dumb luck that it ran good for a little while. I would even suspect a bad AFM over the CAS, but my money is on the wiring. I have a 83turbo AFM and ECU leftover from my z31/MAF swap.. and if you want a CAS I can tell you that any Vg30 CAS can easily be made to fit a L28et dizzy, but you have got the crank mounted CAS correct? Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 27, 2005 Share Posted November 27, 2005 Check out Bastaad's comments on this post. This could be the simple solution to your problem. http://forums.hybridz.org/showthread.php?t=89131&highlight=cleaning+turbo+connectors hahah cool I've been quoted *thumbsup since I don't know how to do a thumbsup smiley*. if you're going to bother with the CAS, just swap it out for an '82-83 dizzy with integral CAS. I HAVE had small issues with the '81 CAS, once when I found my front oil seal was leaking on the motor, before having it rebuilt... some oil got onto the CAS and yeah the car did some funny things. Cleaned it off with spray cleaner and suddenly the car ran great until a few days later after more oil got on it and I knew I had a problem But yeah, for the trouble you will go thru finding one and then installing it and adjusting it, you should just do the '82-83 dizzy swap, get the dizzy and oil pump shaft, should cost you less than $100 (I got mine for $50). Though in this case, I'm betting more on it being a short in your wiring, a bad ground or some corrosion you didn't get when you cleaned things off. Did you clean the connections from ALL your sensors? AFM, head temp, CAS, get all of them. All your connectors at the ECU? Also, clean off the fuel injector connectors. Check all your grounds make sure they are all very clean. And, ghetto as it is, try running the car with your O2 sensor disconnected, then your TPS disconnected, then both. Out of three 280zx's I've owned, they have ALL run better with these two sensors disconnected, I have no idea why! Hey, it's free to try, so why not Quote Link to comment Share on other sites More sharing options...
MaTTSuN Posted November 28, 2005 Author Share Posted November 28, 2005 ive checked all my grounds and went over everything twice. from what ive heard latly from hybridz and from my Z shop guy its a 50/50 the CAS or the AFM i guess i need them both 2 find out for sure but i will clean the CAS and make sure its clean and nothing is getting in the way of signals and what not. as for the AFM ihope i can find one 2 try and go from there. this car is on the edge of being on the road hope ican stop driving my pickup and enjoy another Z thanks again guys ill post an update and some pics when this badass is running Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 28, 2005 Share Posted November 28, 2005 Like I said, at the least, TRY unplugging the O2 sensor and/or the TPS... can't hurt to try. And DON'T discount the possibility of a short in the wiring. This could very well explain the on/off nature of the problem. The wires move slightly and something contacts something it shouldn't and shorts, then moves away and it's fine again. IMO, the on/off nature of the problem indicates that it's probably NOT a bad AFM or CAS so I would bet replacing either one does nothing for you, unless it is just the CAS being dirty. Quote Link to comment Share on other sites More sharing options...
MaTTSuN Posted November 28, 2005 Author Share Posted November 28, 2005 ill go over the whole harness again. but i did paint the CAS with engine paint so i should prob get that stuff off it. and clean the CAS wheel. not sure how the CAS work but maybe take it apart and clean it and seal it but like i siad i dont have a clue how it work i would assume magnet pick-ups. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 28, 2005 Share Posted November 28, 2005 The CAS uses a light emiting diode (LED) to flash a light through the holes in the CAS wheel. The pattern of light on the other side gets read by the sensor to figure out the crank position and rpm. That's a very basic definition of how it works, nothing to do with magnets like the older systems. Quote Link to comment Share on other sites More sharing options...
MaTTSuN Posted November 29, 2005 Author Share Posted November 29, 2005 so that is the 81 with the one mounted outside at the bottom of the engine? so i guess the engine paint could have messed up the "LED's" i shall take it off and clean it and do what i need to do hope its a new leed on good times Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted December 4, 2005 Share Posted December 4, 2005 I think the LED setup is for the '82-83 CAS (the ones internal on the distributor). Isn't the '81 front mount CAS magnetic? It 'reads' the teeth with something like a magnet or piezo electric whatzit I dunno something like that, but I'm 99% sure it's NOT optical. Quote Link to comment Share on other sites More sharing options...
MaTTSuN Posted December 4, 2005 Author Share Posted December 4, 2005 i took it off and cleaned itwith no effect, i think it is a magnet pick-up if it was led the dirt that was on it would not alowed any spark control. i think my problem is the FPR when i take the vacume line off the FPR and plug the vacume it runs great for alittle while...anyone have a FPR go bad? Quote Link to comment Share on other sites More sharing options...
GrayZee Posted December 4, 2005 Share Posted December 4, 2005 I think the LED setup is for the '82-83 CAS (the ones internal on the distributor). Isn't the '81 front mount CAS magnetic? It 'reads' the teeth with something like a magnet or piezo electric whatzit I dunno something like that' date=' but I'm 99% sure it's NOT optical.[/quote'] could very well be, never really saw a crank mounted one. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted December 4, 2005 Share Posted December 4, 2005 i took it off and cleaned itwith no effect, i think it is a magnet pick-up if it was led the dirt that was on it would not alowed any spark control. i think my problem is the FPR when i take the vacume line off the FPR and plug the vacume it runs great for alittle while...anyone have a FPR go bad? did you even bother with my suggestion of unplugging the O2 sensor or TPS? I don't know why you'd be reluctant to try this... free and easy and take all of a minute. Getting the car to run smooth by unplugging the FPR only suggests one thing, that there is a problem with your air/fuel ratio. When you unplug the FPR, fuel pressure SHOULD shoot up a little (usually from 32 to about 38-40psi) so the car runs more richly. If your car suddenly runs much better, seems to me that indicates your car is running too lean. Under normal circumstances, with everything working properly, you should be able to unplug the FPR and the idle should barely change at all (once you plug the end of the hose with your finger). Now, if it was something wrong with the FPR, and unplugging it made the car run better, it should KEEP running better, not run better for a minute then go back to what it was doing before. I think it's possible that the O2 sensor is doing something wrong here. You unplug the FPR, mixture goes richer, car runs better, O2 starts correcting this and suddenly the car is running crappy again. So I say again, TRY unplugging the O2 sensor (leave the FPR connected) and see what happens. I and a few others have ended up just leaving our O2 permanently disconnected and find the car runs better overall like that. My car runs like CRAP if I hook the O2 up, idle gets very rough, the car starts misfiring/popping quite a bit, and feels like crap under part throttle acceleration. By the way FPR's can go bad but it's rare... it's a simple device, just a spring and a diaphram. The spring might get soft over a long period of time or the diaphram would, or the diaphram might even rip. Any of those things would have an effect on fuel pressure, but I've never heard of a bad FPR causing such dramatic effect on a car just sitting at idle or revving under load... it takes HUGE differences in fuel pressure to really have such a negative impact on how the car runs. Case in point, when I installed the MSD fuel pump on my car on the stock return line, my fuel pressure was up to 80psi at idle! The car still ran okay, the idle was lumpier, and my off boost throttle response and power was very noticeably decreased, but it still ran evenly, and except for the extra shake at idle, you'd have been hard pressed to know anything was wrong... you'd just think the motor was a real dog off boost. Quote Link to comment Share on other sites More sharing options...
MaTTSuN Posted December 6, 2005 Author Share Posted December 6, 2005 thats it bastaad some info i can chew on haha sorry for not telling you but i did try unpluging the O2 and TPS sepritly and together with no effect. interesting fuel facts thanks allot so i guess it could be the AFM.. i tried adjusting it a while back i think... like 5-10 teeth maybe i went the wrong way i think i tighten it up and that would make it more lean right... i think im going to pick up a fuel gauge today just so i have one and mess with the AFM more. the Z shop guy siad AFM when i told him what was up on the phone so maybe thats a good bet. ill let you guys know for sure thanks again Matt Quote Link to comment Share on other sites More sharing options...
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