Jersey Posted August 19, 2003 Share Posted August 19, 2003 Hey all. What could be the cause of getting no timing advance on the '82 L28ET that's in my 240? As i understood it, the CAS (Crank Angle Sensor) sends a signal back the the ECM and the ECM sends the appropriate signal to the coil. It just sits at 20deg BTDC all the time. It will not advance even bringing it up into the higher R's. The car does run so i'm assuming everything is ok with the CAS and, i swappd out the ECM with a known good one last night and still, there's no movement off of 20deg, neither advancing/retarding, no matter where the R's are at. I also checked the TPS for operation and it is working properly. I disconnected it while the Z was running and watched the timing, no change - 20deg btdc. Any ideas? Please, i have a feeling this might be a simple problem i'm overlooking and if you have any ideas, please, bounce them off of me. Sincerely, Stumped Quote Link to comment Share on other sites More sharing options...
fl327 Posted August 19, 2003 Share Posted August 19, 2003 /Stupified maybe? I am. Im thinking distributor meaning CAS???usually is ok forever basically, wouldnt hurt to check out though. Ignition, Ignition,Hmmmm.... Something in the EFI thinks its running too lean.... CHTS-if its off, youd be black smoking out the tail pipe. Ignitor out-usually no start ECU failure-no start or no rpm after 2000 Try pulling knock sensor off????-Im sure you have? It gave me this issue till I pulled the plug on it. Maybe, I say maybe, Cap and rotor???? Im sure you checked it Quote Link to comment Share on other sites More sharing options...
Jersey Posted August 19, 2003 Author Share Posted August 19, 2003 It's just unreal that i haven't been able to solve this rich/idle condition. Now i'm going to focus on this no advance issue and i think it'll be the answer, or at least get me in the right direction. I mean, damn, i would have been easier if i spun a bearing or something! At least then i could diagnose and concentrate on THE problem. Unreal. I was told if the CAS was bad, she wouldn't run, and it does, and it is sending a signal of where the pistions are back to the ECM. So i'm pretty sure it's working properly. HTS resistor value at all different temps are in the curve as per FSM. Just not sure of what voltage should be going in and what should be coming out and what wire does what out of the two, but it is creating the right resistance at whatever temp the coolant is. Tried pulling knock sensor wires off, no help. Cap and rotor look fine. CAS looks clean and even blew a little air around in there just in case one of the 3 photo diodes was dusty/dirty - no help. Thanks for all the ideas and keep em coming!! ha. Maybe I keep looking at what i think is the cause and maybe it's actually the effect like...it's not budging over 20deg btdc because the 02 is sending a lean condition to the ecm and not letting it advance? Although the O2 voltage sits at about .4vdc at idle at the sensor and ECM so that should be fine. hmmm.....keep thowing ideas around...the answer's here somewhere! Thanks 327. Quote Link to comment Share on other sites More sharing options...
BayAreaZT Posted August 19, 2003 Share Posted August 19, 2003 Have you checked resistance at the ecu connectors also? You should have the same readings as the component. Maybe there is a harness problem somewhere. Is the CAS aligned right? Just thowing out ideas. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted August 19, 2003 Share Posted August 19, 2003 you and me both Jersey... I've tried so many things to get my car running right, and nothing is making a difference, and I'm about out of things to try. Making me wish I had persued the idea of using a turbo to forcefeed my SU carbs... I've always disliked the Z EFI systems... if I had money I'd put SDS or Megasquirt in a heartbeat... but... I dont. I wish I, like you, at least had a second vehicle to drive in the meantime, because right now driving this thing is only pissing me off more and more. Quote Link to comment Share on other sites More sharing options...
Jersey Posted August 19, 2003 Author Share Posted August 19, 2003 Bay - yes, i check first at each sensor, then go to the FSM and check the pins themselves. I'm not sure if the CAS is aligned right. It doesn't say how to do it in the FSM, although it does say it may become mis-aligned and may need to re-align! I'm doubting as this is it because Sleeper on my other post ahs suggested that the CAS has nothing to do with timing advance, it just tells the ECM where the pistions are. Thanks for the ideas. Keep 'em comin'! 525 - i will figure out what the h*ll is wrong with this thing. I MUST have overlooked something.....well...twice and i'm just not getting it. I will keep trying. It is easier to have a second vehicle. I just wish i had my Z back on the road and get her back to the track!!!! Like you, it pissed me off to apoint to where i put it in the garage and vowed to figure out what was wrong until she went back on the road. Keep trying 525, you'll get it. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted August 19, 2003 Share Posted August 19, 2003 Well today for the first time I made some real headway with my problem, at least, and it's definately ignition. I posted the details on my other thread. If the CAS became misaligned it would affect your overall timing, i.e. you would always be 4* advanced from where you should be, throughout the full range of driving. On the '81 motor you change the timing by moving the posisition of the CAS in relation to the crank wheel, and it changes overall timing. Seems we've both found our problems... just the fixing part is where we are both stumped.... good luck to us both... in the meantime I have to keep driving my car running like crap Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted August 19, 2003 Share Posted August 19, 2003 Now you know why I use N/A ECM. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted August 19, 2003 Share Posted August 19, 2003 Now you know why I use N/A ECM. Do tell... I wouldn't use either one myself, the flapper sucks. That's why I went with the Z31 ECCS. And the NA and turbo Z31 ECCS are so similar, I think a turbo motor is better off with a turbo ECM. Quote Link to comment Share on other sites More sharing options...
Bernardd Posted August 20, 2003 Share Posted August 20, 2003 The flapper door/stock efi is complete dung. I got so flustered with it I changed over to the z31 ecu. No problems since. It's even got built in diagnostics. I guess that doesn't help solve your problems. It seems to me that a common thread here is that all the cars with problems are not stock efi or turbo cars. I would suggest checking to make sure everything is grounded properly. I would also check to see if the shielding from the afm and cas is grounded in the harness. And disconnect the knock sensor. It's useless anyway. What kind of mods were done to the harness during the install? Quote Link to comment Share on other sites More sharing options...
fl327 Posted August 20, 2003 Share Posted August 20, 2003 If its the knock sensor, I said it first Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted August 21, 2003 Share Posted August 21, 2003 The knock sensor doesn't do much and at full throttle nothing at all. I agree on all points that factory EFI pretty much sucks but Jersey likes them and runs better than most with it. My suggestion is convert to non-turbo EFI with the Turbo AFM swap and see how much more power you can make with timing. Alex C Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted August 21, 2003 Share Posted August 21, 2003 I'd be interested in finding out more on how that setup works.... non turbo efi with turbo afm? Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted August 22, 2003 Share Posted August 22, 2003 Non-turbo EFI sounds more like a PITA than interesting to me....but each to his own. Tuning a factory system with non-stock flow injectors and a non-stock AFM Quote Link to comment Share on other sites More sharing options...
yo2001 Posted August 22, 2003 Share Posted August 22, 2003 I ran N/A ECU with BTM before I went to Z31 setup. It actually ran pretty good. Not as good as Z31set going into the boost but as good or better than turbo zx setup. BTM does give littlebit more tunability than turbo CAS setup. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted August 22, 2003 Share Posted August 22, 2003 All I know is after one month of chasing gremlins I'm already WAY tired of the '81 turbo EFI... reminding me of my N/A ZX and the FIVE YEARS I spent chasing gremlins in that system...any cheap alternative is a good alternative at this point. It seems more than a few of you guys are running the z31 setup... now I'm REALLY interested in that as I have a good source for cheap z31 parts. I'm also keeping an eye on Megasquirt progress... may go that route... or the ever popular and expensive (okay well it's relatively cheap I guess) SDS. Wish I had that kind of money at the moment... Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted August 22, 2003 Share Posted August 22, 2003 You said it...tuneablility. You don't have alot with any factory Nissian but at least with the non turbo ECM you can work the igniton for max power. Boost a stock turbo motor 18psi on race gas and a intercooler with timing around 28-32 degrees and tell me if there is a power difference. I know from what I have done and what I have seen, 11.49 @ 119mph n all factory power components (turbo injectors N/A ECM). But I guess whatever works for you. I just picked up a 88T 300zx with a TO4E I guess I will see how far that factory ECM will cary the car. Good luck. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted August 23, 2003 Share Posted August 23, 2003 You said it...tuneablility. You don't have alot with any factory Nissian but at least with the non turbo ECM you can work the igniton for max power. Boost a stock turbo motor 18psi on race gas and a intercooler with timing around 28-32 degrees and tell me if there is a power difference. I know from what I have done and what I have seen, 11.49 @ 119mph n all factory power components (turbo injectors N/A ECM). But I guess whatever works for you. I just picked up a 88T 300zx with a TO4E I guess I will see how far that factory ECM will cary the car. Good luck. I guess I miss your point about "tuning" the ignition then. What's the difference? A na ignition can be tuned for advance, initial and total, but a turbo can also be "tuned" as well. If all you want is max power, set the inital advance to get your total advance where you want it. And give me a break about 119mph on stock turbo injectors. What did you do to flow 400hp from 6 260cc injectors?? It sounds to me like you were driving a ticking bomb. Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted August 25, 2003 Share Posted August 25, 2003 A ticking bomb it may have been but the car ran 11's and was a terror at the street races with very little money and all factory Datsun components. A little hint, NOS carries it own fuel enrichment and done proper lots of power can be made with timing and the N/A ignition gives you more to work with specially when using a BTM or other mulit function igntion controll units. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted August 25, 2003 Share Posted August 25, 2003 A ticking bomb it may have been but the car ran 11's and was a terror at the street races with very little money and all factory Datsun components. A little hint, NOS carries it own fuel enrichment and done proper lots of power can be made with timing and the N/A ignition gives you more to work with specially when using a BTM or other mulit function igntion controll units. All right. You had a wet nitrous kit. I know from what I have done and what I have seen, 11.49 @ 119mph n all factory power components (turbo injectors N/A ECM). That's not exactly all factory components, but now it's believable. I still don't think a turbo ignition is limiting, but I'm not pushing the envelope at the moment. Quote Link to comment Share on other sites More sharing options...
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