86NA starts then dies
 

Hey fellow Z owners. My friend and I have been restoring his Z and ran into something we can't figure out. I put on the jumper cables on wrong and tried to start the Z and nothing happened. :retard: My buddy check the cables to the Z and noticed they were on backwards so he fixed them, then i cranked it and it would run for about 30 seconds then turn off. It will only turn over when the fuel pump has fully primed and when it does run it dies in under 30 seconds. We checked the spark plugs, dizzy cables, fuel pump, fuses in driver kick panel, one fusible link in front of the battery, ECU. Another thing is, it will stay running if we continuously spray starting fluid through the intake.

We've considered dropping the fuel tank and blowing out the fuel rails in case some gunk got in there and stopped things up and also considered a new alternator. This has been ongoing for about 3 months and my friend is ready to give up but my love for Zs is too much to let this thing sit and rot.

What do I do?! I've also looked through the FSM and I have a Hayne's manual but I can't find anything about this. HELP!! :087:

Welcome to ZDriver!

This means the injectors aren't spraying fuel. You most likely toasted the ecu and a lot of other electronics by jumping it backwards. Do the ECU LED lights turn on with the ignition?

We pulled the ECU and got a code for CHTS.

Reading last night
 

It would take awhile to find. I was reading the Shop Manual on the Z31 Electronics. I seen a reference to a BREAKER or trip switch that cuts the signal off to the ECU. ENGINE FUEL & EMISSION CONTROL SYSTEM Section of the shop manual, the next chapter in the shop manual is Electrical and I was reading that some as well but I thought I seen reference in the emission Control area. But I do know there is a fail safe just for that incase you cross the jumper wires.

Wouldn't the car not start if that breaker was tripped though?

I just took small note in my mind as I was searching for other things a remembered coming across that. Not sure what path it trips but its so the ECU don't get fried. ECU sends info PLus gets it, the inward path to something is cut off. Junk in Junk out. Check back in a little bit and I will try to find the REF to that. 190 some pages have to quick read but I will find it.

Safety relay
 

http://i948.photobucket.com/albums/a...h_IMG_1161.jpg This trips out when you cross wires, make sure the relay is not fried or reset it.

Link
 

http://i948.photobucket.com/albums/a..._Will/link.jpg Here is the link you asked about in PM. Very helpful. In the read this 1ST Notification private message when you join this site.

Hit us back on what that relay looks like, how it works if it has a reset button or what not. The shop manual didn't have much to say about that other then its a fail safe. But it is listed within the manual as a fix it so I am thinking that it has a reset. If it reset itself then it would have not been in that section of the manual I was reading in the latter parts of the manual. Check all your small ground as well on the wiring harness near the injector wires. Thanks

Sorry guys, I haven't had a chance to get down to my friend's Z. :012: I'll post an update when I can get down there.

Nismopick do you recommend a new ECU?
Saab I've checked the fusible links but I don't see any breakers or anything of that nature.:102:

Did you check the safety relay? going to read up on a small section within the shop manual about that. hard to find but it said something about a transmitter I think? But has something to do with the signal to the ECU of what the coil gets. The angle sensor path is effected in some way. There wasn't much of a write up but it was simple. Looking now and I will check back. But just in case check that safety relay pull the little cover off and see if the contacts are not burned, and make sure the relay is not stuck in one position because you said them cables were crossed for awhile. Hang online a bit reading now but going to take some time to find because it was something I came across.

What you need to do.
 

Ok found what you have to do. When you joined this site NismoPick setup some downloads of Shop Manuals in your Private Message Notifications Welcome. Download the Z-31 Manual, then go to EFEC area.. Then go to Page 92 & 93 reads EF & EC-92 and EF & EC-93. I am putting photos up but don't think they will be large enough unless you can zoom in.

Alright I'm trying to get him on the phone so I can get down there and investigate more. He's one to not call you back :disgust: So when he gives me a call and I can get down there, I'll let you know what i find out. Until then I'll try to find what you were talking about and find those pages/ pictures. I'm more hopeful now :040:

Tryed
 

Couldn't get better photos from that file but anyways your ECU was saving this code as a malfunction. In the manual shows you how to test each component. ECU is getting mis information JUNK in JUNK OUT. Go though that and you should be able to solve the problem. Let us know what you find out interested in knowing.

confused
 

I compared my pages to the pictures you posted and was wondering if you downloaded the right manual.

Edit: I found out what i need as far as the manual goes. Still haven't heard from my buddy though

yeah its the right manual Z31 That's transmitter is probably very delicate and don't think much would take it out like a power surge. Sort of a very tiny relay.

Put my ECU in it and runs fine. Only thing is when you get on WOT it sputters so bad. didnt do a diagnostics test on it cause its too dark. any ideas before i get the test done? Hes using my ECU until he gets a new one, so he can get it registered and inspected etc

Still need to go though that check list for code 21. See what codes your ECU has in his car.

its the ECU, I had the same problem, had 2 ecus and took one to this shop where a guy does some work for them on computers, he did some soldering and it worked, the shop charged me $350 which is so high and ridiculous, as they did the repair without telling me it would cost so much, I ended up paying $250 which is still too much. but hey it got the car running fine. especially since I bought it so cheap because it wasn't running lol

Schweet, We're going to the junkyard today to get an ECU and possibly a new alternator, his AC and digi dash kept coming in and out while we were driving it. :102: I guess depending on what the codes throw will determine what we do next. We'll be working on the car all day so I'll keep you guys updated!:048:

if your digi dash keeps going in and out, (mine the temp gauge, oil pressure, and battery voltage kept going in and out) then that would be the power supply, its located under the dash, right where your right knee would be, its a silver box, I took mine out and opened it up, had some cracked solder joints and cold solders, just redid that and it works fine now, I also heard of people soldering the wires straight to the box, or even jamming something between the connecter and the box so it makes better contact. like I said I replaced everything on the car and it wouldn't run, then I finally got the ECU repaired and it started right up and stayed running. just make sure you get the proper ECU # for your year and auto/manual or turbo/non turbo.

Hey Cords Dig your floor mat, should have her make some for you Z. Nice Job.