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When cold, I start the engine. It starts perfect and goes to high idle at around 1500 RPM. Five to seven second into this it dies. It does not chug or stumble before dieing. It dies flat out just like you turned the ignition off or cut the fuel supply off.


when my truck ran <img src="/forums/images/graemlins/shiner.gif" alt="" /> it did the same exact thing, was very challenging to keep it running from cold start enough to get up in temp until she kept herself afloat. after temps got up, purred like a kitten. I never figured it out before I tore it all apart for other stuff.

with the idle system of the 4Z's, it can be just about everything mentioned above. I also thought it seemed like some fuel-cut situation going on, as the way it would die was so drastic.

I'm almost leaning towards the thermal vacuum valve is stuck wide open, so after the intital high idle start, the EGR snuffs it out. but then again, the transducer should prevent that if there is no exhaust pressure.

anyway a faulty vsv for the fuel pressure regulator could come into play with this scenario?
<img src="/forums/images/graemlins/confused.gif" alt="" />

2.6 Trooper
2.0 Impulse Turbo