Hi Guys, Please help. The Z stalls when the car is hot. I can only start it back when it cools down for 10 to 15 mins. What do you think cause this problem. Could it be the Throttle Position Sensor TPs or the Idle Air Control Valve IACV or the MAF. Regards,
My guess is the IACV plunger is stuck! If the TPS closed system was failing - the fuel cut would make it hard to start altogether. If the MAF was a problem it would have trouble whether hot or cold. So it sounds to me like the IACV bimetal is stuck in the open position and failing to close when hot and thus its typical for the car to stall when hot and restart when cold - So I would be checking this first and looking at this part. Its most likely failing to close so you will need to check the ground as part of the continuity test but remember the continuity or voltage test may not show up the problem if the plunger is stuck by carbon etc. In this scenario it will need to come apart for testing but first you can try to spray some WD40 in there first then try to budge it by applying the voltage test check. You can also try the accelerator on full when cold starting but this is not also definitive. This is what I think anyway but you should discount the others by doing diagnostics first just to make sure, as it is difficult to remove and given the problems of removing you should run also continuity and voltage test in place first to assist in getting a definitive answer first (if possible). But be aware that there is no self diagnostic for the IACV, if the plunger is stuck! (which is what I believe is taking place hence it is shutting down on hot) Ideally you will detect an electrical anomaly when testing so it can be confirmed before going to the trouble of removing and inspecting/ repairing it Good Luck JC
Have you cleaned yours yet? Could also be wires expanding when hot causing a connection to break, go over and check all the wiring connectors and make sure they're clean and tight before you replace anything. Also, are you using a S2 PTU?
First rule of diagnosis on z32... check codes. Shooting from the hip, there are several things that can bring about what you are describing, the most common "heat related" won't run issue that I have read about over the years of messing with the VG is the PTU failing from heat soak.
Forget shooting from the hip - take an accurate aimed shot You obviously have not had an IACV fail in opening MaxxAction- The IACV is not self diagnostic (and so will not necessarily throw a code)- it requires manual checking at the hose (for leaks) and the contacts for earth and continuity and for plunger action (the difficult part) - see the manual under stalling and you will find it listed as one of the causes Just go through the steps as per the manual Vasny001 as per stalling and you will be able to determine whether this is the part that is faulty Having said that - all S1 PTU's fail eventually and should be replaced regardless (as per the recall notice by Nissan) as they can cause many strange issues and codes that can be difficult to diagnose JC
