I'm working on my son's Z-31 and was told that Z-32 engine was based on this one, so I presume some things are very similar.The whole thing started from hunting, irregular idle and running very rich. Because he also had leaky injectors from some time I was thinking of changing them as well.So here's the list of what I have done so far to the car:6 brand new injectors and connectors new fuel pressure regulator new fuel temperature sensor new fuel filter new TPS new coolant-temperature sensor new cold-start valve (air regulator) new spark plugs new ignition coil new distributor cap + rotor new power transistor PCV valve cleaned EGR control valve checked (ok) vacuum control valve cleaned + checked (ok) AAC valve (idle-up solenoid) cleaned + checked (ok) air flow meter swapped for a good one-checked (ok) ECCS (computer) checked on another car, it works ok. EGR control solenoid valve checked (ok) pressure regulator control solenoid valve checked (ok) pressure regulator control module checked for dry joints-seems ok all vacuum lines changed for new, no vacuum leaks or blockages throttle body cleaned and sprayed with the whole can of Amsoil carbie cleaner (thanks Tony for the Amsoil) all contacts were cleaned and some replaced ground wiring checked (ok) After all those changes it is still hunting and running rich, but not all the time. When it runs good it really runs good, it doesn't have any loss of power, it's responsive and handles great, but when goes bad it feels like its flooded with petrol.Usually when I start it (cold) it's a bit rough and too rich, after a few minutes when it reaches temperature it works perfect. I take it for a spin, it runs great for a while and then it starts blowing black smoke and gets very rich.Than after 1km or 2 comes back to normal, runs perfect for another 10kms or sometimes for the rest of the day with just a few hiccups during the cruising, or other times will stay rough. After the run I check the computer and it says everything is ok.Today I checked and wiggled all the fuses, wires, relays, harness on the perfectly running engine and it didn't go bad during this time, then I stopped the car and started it again and the hunting was back, after minute or two it went good again.Looks like all these changes didn't fix my original problem.Here's a diagram of what I'm talking about, maybe it'll help:[image]http://members.optusnet.com.au/mczx/temp/diag31.jpg[/image]I closed the circle and don't know what else to check or look for, so if any of you can help, please do.
coolant-temperature sensor most mixture settings are usally related to the coolant-temperature sensor.you could check the ohms. at the ECCS when it is running good & bad this way you are checking the wiring as well.that is if you know the pinout on the ECCS.Good luck. Phil.
Yeah, I know this is a common problem, so that was one of the first things I replaced for new, also I changed connector and the loom, readings of the resistance + temp. are ok. The same problem was occuring on the old sensor as it is now on the new one.
Check all connectors for corrosion and dirty ...contacts. It sounds like you are describing an intermittent fault, probably electrical.Using electrical [contact] cleaner spray, remove/clean and refit every plug under the bonnet.Or trade up to a Z32??
Yep, that could be electrical,.... but not the contacts mate, I cleaned them all and some replaced it. I already have Z32. I'm suspecting the distributor have to check it up, thx anyway
Z32 for yr son too :YD My 17y/o wants mine! Not getting it yet :N(I say electrical, because you mention different scenario occurring between 'when cold' as opposed to 'when hot', so if all connectors clean it may be a BAD contact, heat causes metal contact to 'make or break'.Hard to fathom ... but good luck.
He's a P-plater so no Z32 TT for him yet 8( but he doesn't want NA either so he's stuck with Z31 for now
Have you checked the actual loom itself for short circuits. As it's intermittent I am inclined to say an intermittent short. Found a number of these on my Z32 injector loom. Remember to disconnect your computer and sensors/actuators prior to doing insulation checks otherwise you risk damaging the sensors. Hope this helps mate phil:YD
I'm currently waitng for the part which I'm suspecting could be a problem, but if it isn't then I'll chase electrical problems, thx mate
