1994 AusDel 2+2 Stock 159K trouble free. have never had an issue, runs sweet as a nut! I came home in her the other night and she ran as normal, had tea, went back out a few hours later to go and get my daughter from work and she sounded like a V8 big block and ran like crap.Missing on 1 or 2?? This happened for a couple of K's and came good . the car ran normally for a further week then repeated the scenario on friday, so I dropped her into the wrench ( still runnin sick) on Sat morning and tossed him the keys. He had it a day, upon collection he says 'no charge' cant find a thing wrong! ??? feedback please - thanks gang! Vulcan
Sounds rather electrical. It's definitely worth cleaning and re-tensioning the injector and coilpack connectors. Does it have a series 2 PTU? I think '94 was when they came out so if it's an early '94 model it may have a series one. Now that the series 2 units are so cheap I'd be swapping that over if you have a series one just as a preventitive measure, and who knows, may fix your problem... Also maybe try jiggling on wires while it's running to see if you can make it happen? Again, PTU, coilpacks and injectors would be the place to start. maybe worth double checking the big connector between the loom and ECU too, probably not that though. Also check the state of the spark plugs, they may be due a change or may give you some hints as to what's wrong. Use a multimetre to check the resistance in the injectors too, shoudl be about 12Ohms from memory. Maybe change the fuel filter too, could be a bit of gunk coming through and blocking up an injector or 2. Failing that, compression check???
How would I identify a S1 PTU? is there a model # on it or physical difference? Thanks to all helping out Vulcan
They look quite different, series 1 is bigger with a metal plate with cooling fins on it, series 2 is smaller, less rectangular and black plastic. In the tech section there is a how-to article on installing a series 2 PTU which has pictures of both.
Search is your friend. here you go http://tech.aus300zx.com/ type in - series 1 ptu repair - to find pictures
Saga continues: So, I listened to the brotherhood and I agreed with the scenario it may be the PTU-S1 soooo..... I wet and fired the ol gal up and while she was running ( on 4/5 pots...not happy) I lifted the bonnet and and gently pushed the wiring harness connector on the RH side of PTU1.....the problem got markedly worse and she stalled. Started her up again and this time wriggled the wiring loom a few inches below the connector and she cut out dead and has not started since. I proceeded to purchase a PTU-2 Kit, Got one from Nissan in the US, checked the part numbers (same as Oz) and purchased the recall kit- comes with nuts bolts mounting plate pTU and modded harness all individuly packed in Nissan plastic bags with factory numbers in a nissan box- $165 ( small sidestep here- Quoted $1374 from Nissan Oz, none in Oz will have to order- ouch) I attempted to fit it on Sunday, inspecting the original connections which look as new once the protective rubber covers were removed, i proceded to fit the PTU2 to the main loom, I did not fit it back onto the motor as I wanted to test the motor first, which I did.....and guess what........nada........sameo sameo.......maybe the original connectors are shot I dunno, they look almost like new? I have ordered a pair from Ian. Anything beyond this is most likely in the too hard basket for my ability. Any idea's gang? Vulcan. My red sled is dead..boohoo!
the S1 connectors are just much a cause of a misfire as the S1 PTU itself. The piggyback adaptor leads that often come with the kits are still utilising these aged and perished connectors. Solder is the key Either cut up your adaptor leads, or get to a wreckers and source the distributor plug leads from the following cars- a. N15 Pulsar- Identical to the S2 PTU 6-Pin connector b. Mitsubishi Magna V6 24-valve - Identical to the S2 PTU 7-Pin connector. Will give you ample length of wiring to stagger your solder joints, and cheapest option by far.
You sure its not the CAS connection and by wiggling near the PTU your causing the CAS connector to wiggle around too?
CAS?.....? I mearly tool my index finger and pushed the wireing loom 1 cm below the R/H connector to create a stalled motor, did this twice to make sure it wasn't coincidental. the wiring loom was fitted rock solid . Sorry, dont know what CAS is...ever learning..........Vulcan
As stated, I have ordered them from Ian, the original connectors are not perished by any stretch of the imagination, in fact they look bloody marvelous for their age( as a computer tech I can attest to this) however I have not run a continuity test on the internal connectivity of the original plugs(connectors). Cheers Vulcan
Make sure the receiving connector didn't have it's connectors pushed back into it's holder preventing 100% good contact. While you are in the process, it may be a good time to relocate your PTU to a conveniant spot under the center nose panel. Search my screen name using PTU as a search-word to find pics of my relocation of my Series 1 and series 2 PTU's. Most people find it odd that the factory would mount an electronic/electrical item such as the PTU to the front of the timing belt cover. These units do get warm on their own and the additional engine bay heat only serves to possible shorten their lives. Without turning the engine on turn the ignition to on and feel if the PTU appears to be getting excessively hot. The slight movement of the lead-in harness to cause the engine to die may reveal a short within the insulation of that lead-in / sub-harness. Unwind the tape for that harness as far back as possible towards the fuse box (past the 2 coolant temp sensors) to inspect the wiring. Once you've got that far, you're almost halfway there to your PTU relocation already.
yep - agreed, I know about the relocation, looks like i have to find a dud wire or 2 in the loom or hand it to a wrench and pay the big bucks.....oh poo! Vulcan
The PTU wiring is taped to a couple of other wires on the front of the engine but can easily be un-taped and relocated almost anywhere, mine is next to the battery.
Under the nose panel area seems to be the logical choice given the initial reason for relocation was due to removing it from the hot engine bay area. Placing it in another location in the engine bay really won't accomplish very much. Electronic components should be kept away from excessively hot areas.
latest news....cleaned contacts ob old PTU1 and fitted back onto Z, this time she fired up ok but stil had misfire. switched off motor and reattached PTU2, she fired up againd on new PTU unlike first attempt. Chect cintinuity of original loom connectors and they are ok, so its possobly injector/plug(s)or maybe cas??? taking to a wrench on Mon/tues...........beyond my capability now. cheers to all the imput Vulcan
Yeh, no worries....I will also wear my glases so I don.t send as many typo's....old and blind...... vulcan
So the series 2 PTU works better or starts better or both than the series 1 PTU? It seems cleaning the PTU contacts did make a difference. Some PTU connectors can look pretty nasty with substantial oxidization build-up that looks green in color. My best method to make sure all of that stuff is removed is to pour an anti-rust/lime/corrosion liquid - CLR into a rattle paint can top or small cup. Disconnect the ptu connectors and soak each connector submerged in that cleaner for a few hours. Do that for both connectors. Once they've soaked for a few hours, remove and clean off with micro files and auto micro-pics (similar to dental pics). Ensure none of the metal connectors within each harness doesn't get pushed back into it's hard plastic shielding. That is a common occurance when a PTU has been connected and disconnected numerous times and it's hard to notice when it happens unless you have the rubber chielding on the backside of that harness connector peeled back and can actually see one or more of the wire connector leads being pushed back when the two main connectors are connected together. If you've had any kind of corrosion build-up on the PTU connectors than it's a safe bet you also have just as much if not more on the injector connectors. Make a very thorough check of each injector connector. There are How-To's to check to see each injector is "clicking" correctly. Next would be to check the connectors for the coilpacks for corrosion as well. Then to the IAA and Air Regulator connectors. Testing of those components is contained in the Swipnet pinks I've posted in other threads. Search my screen name and use "Swipnet". Next would be to pull the plugs to check for color and correect fuel burn. Please confirm the exact brand and type of spark plug you are using. An NA's plugs should be gapped to .044" and a TT's to .035" as I don't know 100% if you have an NA or TT. TT's should use the NGK PFR6B-11B and the NA's use (IIRC) NGK PFR6b-11. I would also do the CLR cleaner routine to the CAS and MAF connectors as well. The only way I was able to remove all traces of corrosion was to use those automotive mini/micro files and and those automotive pics.
