I'd swap out the PTU first before digging around the ign switch. Both are possible causes but PTU is more likely. You can /bypass eliminate ign switch as a possibility by shorting the two closer female terminals on the ign relay in relay box next to passenger side throttle body. This provides constant 12V to ign circuit. Don't leave it in permanently though. If problem persists with this bypass then you can eliminate ign switch for now and concentrate on PTU.
sounds good. Thanks for that. Im gonna dedicate a day to finding it hopefully next week sometime. I plan to go over everything and maybe hook up a laptop log everything to see if a particular sensor reads something odd as the cars cutting out. Hopefully i can get a zed helper so i can temporarily switch things like the ptu see if the problems eliminated..
hey guys i have a quick question here. I went over a bunch of things again and just had a test run. No change, it still cut out. So my next step is to get a laptop and log all sensor values to see if anything shows random numbers just before it cuts out. But i noticed something interesting this time i havent mentioned before. When the engine switched off, i left the key as it was. The engine wasnt running, and my ecutalk display wasnt working, but the auxillary fan was running. If i switched off the car straight away and turned it back on it wouldnt start but the fan would turn on again. if this is for an obvious reason please inform me of it. Im hoping it only happens when a particular sensor is unplugged or something? Any light shed on this would be much appreciated... Thanks a lot. Hope someone can help...
Yeah i have. Even opened up the ecu to check it all looked ok, and checked out the loom as far back towards the firewall as i could. All looked fine.
That sounds lime a fault with the coolant temp sensor. No error code 13? Ifnot, check what ECu talk says the CTS is reporting...
Have you checked the wirring to the ignition switch ?.Also my temp sensor was playing up but it did not show a fault just read real low 30 when i new the car was hot , also the fan was coming on acasionally but the car never cut out.
coolant temperatures were fine i think. It got upto 83 then set there about 5 mins reading few points up or down steadily then cut out without any random readings. I went over all my ignition wiring and redid my turbo timer wiring here. As long as the wires were all soldered to their correct spots, its all clean now. (t.timer has worked fine since install so i assume wirings correct). I soldered a new coolant temp sensor connector on about a week ago. So that might be dodgy, but ill check it out. It was cutting out before that though, but i dont remember the aux fan ever coming on. Ill check the CTS tomorrow, and hopefully set a date to hook up the laptop and log values.
ECU turns on aux fan if it is getting irregular input from CTS. In your past post you said " . What do you mean by that? Also what error codes??? If code 13 then check the connector wiring and if all good and the temp sensor is within the following specs: Temps ---------- Resistance Ω 20C ------------- 2.1 - 2.9 50 -------------- 0.68 - 1.00 80 -------------- 0.30 - 0.33 then I'd check the wiring and if possible run a continuity test between the CTS and the ECU (wiring diagram here). I've seen several continuity problems in the CTS <> ECU wiring circuit not attributed to the end connections. These are extremely difficult to pinpoint without disturbing the loom too much (not advised if possible).:bash: I run 4 metres of twin core wire with black sheath (from Repco) in new circuit and problem fixed. Wiring problems inside looms are rare but possible.
ah sorry. My ecutalk display doesnt read any CTS resistances, just a temperature reading. I meant it still read 84degrees until it cut out. How do i check the resistances? Just with a multimeter while the cars idling and warming up? Or will a laptop and ecutalk on that give actual resistance readings? theres no error code and hasnt been one throughout the duration of the problem. How do i do a continuity test? Ie. What is it? Ill give all this a go tomorrow.
No - use a multimeter set to continuity Ω. Place the multimeter probes between the CTS terminals (you can use the needle end of the probe to carefully insert the probe into the wiring connector terminals). However the temp display should also show if the CTS is giving any strange readings as the values should be varying wildly (for example 80deg then 20deg then 60deg then 90 etc). If you aren't seeing this happening on ECU talk then the CTS is probably OK. What is the current situation? Try starting the car from cold and record some sensor readings via ECU talk as the car warms up indicating if the aux fan is on constantly etc, also go for a squirt and check the readings then report them back here would be my suggestion. Very hard to diagnose via www...
yeah airstyle (greg) is coming over tomorrow with the laptop so well have a little look arround and log values from cold until it happens. Then check if we can find whats happening.
Hey, might be a longshot, but maybe AndyMac had the solution (sort of) way back in the fourth post of this thread. Might sound very random, but if you get an airhose from a compressor, run the car till it dies, then one by one cool a suspect component, try to start, etc., etc., till it starts again. A bit of trial and error to confirm a few times that cooling that particular component was the reason it started, and not just the time factor, and you at least know where to look for a dodgy connection. Forty years ago I had an XL falcon with a dodgy coil and I spent many hours (in ten minute increments) waiting for it cool down and fix itself. Only just now realised I should have been carrying a gallon of water with me.
yeah i think ill give that a go if logging doesnt reveal anything. I hooked up a laptop and tried to get ecutalk working. But I couldnt get it to connect properly Going away for 3 weeks now so wont be able to do anything but ill continue where i left off soon as i get back.
My 300zx is doing exactly them same thing as yours goes for a bit and then just dies was missing on the left side and now its missing on the right the left stopped missing hard to figure i may have to take it to nissan so they can fix it.But that will be after i put on my new prolite flywheel when it gets here from the usa.
My Z was doing this.... This thread sounds a lot like something I went through. Very frustrating when you cant get to the bottom of a problem like this. I went through a lengthy process (I wont put you through it....). It was my AFM. Motor was randomly losing power and cutting out. After sitting for a while it would re-start. These are expensive, so the best way to accurately diagnose is to borrow someone else's for a while. Also you can try this if you get stuck on the side of the road......unplug your AFM and it will start and run normally. You will be able to drive it but your rev will be restricted to 2500rpm (from memory). I managed to drive mine from Brisbane to the Gold Coast like this after getting stuck when the AFM finally died completely. Good luck and hope this helps!
Hmm this sounds promising actually. When it first started happening I suspected it was the ptu. There was a point where it got more frequent and eventually did it every time i tried to drive it. Then one day I could drive it but the revs could only hit a certain point before the car clurched forward and didnt rev any higher. Then I swapped to a s2 ptu and it just got to hte point its at now- cuts out shortly after reaching operating temp. I havent checked the afm or its wiring very thoroughly yet. Ill do so when I get back to syd.
Its well worth a look at least. I had issues with engine faltering etc as well. The AFM connectors are a common place where corrosion can really set in. Give them a really good clean first and a spray with some contact spray. If this doesn't fix it try to borrow someones (if you can) and you'll know quickly. Also if the car starts with and runs with your AFM unplugged when it wont with it plugged in you have found your problem. Started with just a couple of rev drops while I was driving. Then progressively got worse over time. I thought I had a fuel problem (felt a bit like I was running out of fuel while driving). Then went to the PTU. Replaced that. Still no improvement. After cleaning every connection in the engine bay and a wide variety of other investigations I finally decided to take it down to Gavin Woods workshop on the Gold Coast. I only just got out of Brisbane when it finally died completely. It was only then that I was messing around under the bonnet and tried leaving the AFM unplugged and hey presto, it started!.......so I drove on 2500 rpm all the way to the Gold Coast. These cars can be frustrating as there can be numerous things that can cause the same symptoms and it can be very frustrating getting to the bottom of it. Good luck anyway, i hope your solution ends up a cheap one
I started the car yesterday after it started kept on trying to stall but if i pumped the accelerator pedal like mad the revs came back up but as soon as they did it would try too stall again i did this 6 times before it would idle but it was still missing a bit on the right side exhaust pipe.
