So un-impressed right now. long story short, car doesn't work. I've got the testing information from the service manual for the PTU (satan spawn) and will test it after work tomorrow night, but does anyone know what I should be looking for in testing the loom. I'm sure I'll work it out tomorrow night, but in a moment of weakness, I am humbly asking for some assistance. Oh and I accidentally stepped on/possible sat on the drivers side timing belt cover and it literally shattered into 43 pieces, so I've done a relocation of the PTU and decided to go topless from now on, but I've got a nagging feeling, although I was sooooo freaking careful with the loom, that with my track record I've damaged it. :help:
I would clean your Electrical Connections first off... Here... http://www.aus300zx.com/forum/showthread.php?t=290913
Yeah Andy, problem is more likely a poor connection between ecu and ptu - rather than a faulty ptu itself. especially after flexing the loom while doing the 100,000k service mate, seen this a bazillian times. check, clean and retention connector pins. if problem persists try a continuity check between the pins on the ecu connector through to the ptu input side.
yeah cleaned and retensioned all the pins, guess I'll have to check pin to ecu continuity, such a pain.
Had one of My pins pushing the mating side out and not making contact after retensioning them, little locking tabs were not holding it in place, but couldn't see it as it was covered. continuity check is the way to go. Think i have a couple of covers here if you want to go back that way, naked is good though.
ok, attacked it again. Tested the PTU as per the service manual testing procedure testing proc...although for those that know it, i got continuity with the opposite polarity than as described by the test. And yes I have my multimeter setup correctly. So I'm just a bit confused, as to whether a failed PTU will exhibit these signs? I also checked for spark while my housemate cranked it, and I had a weak spark, and I have fuel. I've attached a second earth to the earth wire as well to see if that helps, but no, no kick. just cranks along. Oh and i've tested all the wiring as well...all good. Any thoughts guys?
Try wiggling the cas connector while cranking. It is unlikely the ptu failed when not in use. Did you fit the 3 earth wires back to the plenum? I assume you would have not being a noob.
All earth sensors were attached. 100%. CAS and connector are ok, the pump primes when the connector is taken off and on, and i can get the injectors to fire by rotating the CAS, so I'm confident that's not it. All i did with the PTU was remove it from the cover and put it next to the fuse box. I've stripped back all the loom and all wiring is in good condition and there in continuity back to the ecu on all of them. The earth wire has continuity to the plenum. I pulled a coil pack to check for spark and there is a spark, there is fuel. there is air! But the bitch just won't start.
What did you do during the plenum pull? Just coolant bypass or injectors aswell? Is the spark strong? What is the output voltage from the ptu during crank? Using consult what is the injector m/s during crank? The injectors are batch fired during crank and should show somewhere around 6m/s charge time. Plugs not fouled? Cas timing ok? Did you have anything else apart on the car?
What did you do during the plenum pull? Just coolant bypass or injectors aswell? Timing belt change. The only reason the plenum was off was to remove the egr Is the spark strong? No, visible but not strong What is the output voltage from the ptu during crank? haven't tested yet, pin to ground yes? I'll test when i can rope in an assistant Using consult what is the injector m/s during crank? The injectors are batch fired during crank and should show somewhere around 6m/s charge time. 5-7ms Plugs not fouled? I hope so, cause that will be nice and simple...thats tomorrows try, they are iridiums so if I did already fix the wiring issue it may have permenately screwed the plugs in the meantime. Cas timing ok? Spot on Did you have anything else apart on the car? no, only front end work
As you know, iridiums can foul very easily, they can be bought back to life with a light sand blast of the electrode and insulator if your in a bind. Pull them out and put a set of platinums in, I would stay away from coppers, but that is my personal opinion. Most likely the wiring was at fualt and excessive cranking with week spark has fouled them.
I'm assuming here that for none of the cylinders to fire it is the earth wire to the PTU that is/was not right. Because even if one cylinder would kick i'd hear it. In this scenario would you still get a spark? Even a weak one? That's why i'm a bit confused...although I didn't physically check for a spark until after I went over the loom with a fine toothed comb AND ran another earth wire from the neg terminal to the PTU. So i guess the question there is...IF the PTU is still not wired correctly or buggered, would I still get any spark, because they way i understand it the answer should be no.
Depending on how the ptu was wired incorrectly, you may or may not get spark. If it was a bad earth to the ptu and you tried cranking it on and off over a good ammount of time, it is likely that the plugs have fouled. Did you actually find the earth was no good? It may have just been poor connections at the ptu causing a weak spark. I think the first thing to try is new plugs. Check the spark with them before you put them in, also put the battery on charge or use a good jumper pack.
No, didn't find any issues with the wiring at all. I got continuity accross the board. I ran a secondary earth as a precaution, or a "just in case" measure, as it were.
The plugs can still spark with a small blue spark that sort if looks OK if the iridiums are screwed. The spark has to be bright WHITE and intense. Happened to me. thought I had good spark, but plugs where rooted. IMO your plugs are buggered if spark look weak and blue.
ok, new plugs same dealio. Weak spark on cranking. I'm going to have to try another PTU...Any sydney boys have a spare "known working" PTU lying around I can try?
