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FocusGroupy 01-09-2013 02:17 AM

2000 zx3 won't idle, sometimes

My daughters 2000 ZX3 runs fine most of the time. But occasionally, after being driven for a while and shut off and restarted it will not idle and die. You can keep it running by applying a little pressure to the gas peddle. If you wait about 45 min to an hour usually it will run normally again.

It seems totally random. sometimes it will not do it for weeks or months (the longer times between events are in the winter).

My scanner can only read codes, it can't read things like fuel pressure and real time data. No Codes are set.

Any ideas?



BC_ZX3 01-09-2013 10:35 PM

Usually a vacuum leak of some sort. Hoses tend to be more pliable when warm and a split or perished hose may leak under only those specific conditions. Check for the common PCV hose failure problem and all the rubberr fittings that attach to the vacuum take-offs on the back of the intake manifold (just below the throttle body between the manifold and firewall.)
Vacuum leaks don't usually throw codes unless they affect the AF mixture enough to cause a lean running condition.

my_beautious_ZX3 01-09-2013 10:41 PM

hi and welcome to the forum.

another thing to check is the IAC valve.

stalling is a classic Focus failure mode on older vehicles and a topic of endless discussion here. Plug words like "IAC", "PCV", and "stall" in the search box to find tips.

FocusGroupy 01-14-2013 03:16 PM





whynotthinkwhynot 01-14-2013 03:28 PM

Because it runs fine, then won't restart, I am inclined to believe that is an IACV problem. The IACV is simply sticking once in a while- probably due to the cold weather and crud buildup. I would clean the IAC.

There is no reason not to investigate the PCV, check it, and repair it as needed. This is a common problem causer, and should not be overlooked any time you're having problems with the car. It will help you to know this one, and know it is repaired. It is not expensive to repair if you purchase 90 deg plastic elbows and line to build your own. A re-designed hose from Ford is available for $20.

mjtalas 12-22-2013 07:42 AM

My 2001 ZX3 has the same problem as described in the original post. Was there ever a resolution to this? I see many threads about idle problems, but most involve other symptoms (rough, low or high idle). For this problem, the engine simply will not idle without my foot on the accelerator. As long as I keep my foot on the accelerator even at low idle the engine runs fine. As soon as I take my foot off the accelerator the engine dies. This happens every few months and seems to be random. After sitting for a few hours (not sure how long I need but overnight is the typical amount of time) the problem disappears and the engine idles normally again.

This has happened a few times and to drive the car home I need to keep my left foot on the break while the car is in drive and then accelerate to get the car moving (almost like a clutch on a standard shift). While driving I coast in neutral with my foot on the accelerator to keep the engine idling and then drop it back into drive to continue driving. All the time, I have to keep my foot on the accelerator and keep the idle at around 3000 RPM. A lower RPM might work but I need the higher RPM to keep the engine running once it is under load and the higher RPM is easier to maintain with my foot.

The next morning the car starts and idles fine with no problems. I have tried waiting a few minutes before restarting, no luck. I have also disconnected the battery cable to cut all power hoping for some sort of reset. No luck. The only thing that seems to bring it all back to normal is sitting overnight. Not sure how long I actually need, but overnight is long enough.

Kodyston 12-22-2013 11:18 AM

Try cleaning the IACV as mentioned above. If you don't want to clean it, buy a new OEM one. Check for vacuum leaks/cracks in your vacuum lines and see if the car idles better. Let us know if that helped.
