1.9l AAZ, stopping from hiway speeds, engine dies

[pitargue]

I just put in a new 1.9l AAZ NA engine into my caddy.  Came w/ 1.9l injectors and 1.9l IP.  The IP was timed to .91mm.  Engine idles well, and around town, is just about perfect.

However, when coming off the freeway, going from say 65 to 0 (stop), the engine will die.  It starts right back up and idles fine.  It seems the engine is starved of fuel in this scenario.  Tried to bump my idle a bit more, but does the same thing.  It's like there's a fuel cutoff from high rpm to idle, but doesn't resume fuel to keep the engine idling.  But then, when restarted, acts like nothing happened.  What gives?

Any help appreciated.

[hillfolk'r]

shoot i was gonna suggest too low of an idle,but ya tried it..on my old td jetta i had it set too low and it was so bad if i redlined it and shifted to neutral it would die,and id have a heck of a time restarting it.
like once or twice i almost killed the battery...try bumping the idle a little more maybe tho,its worth a try..try to get it so the revs drop nicely without hanging(like when ya turn up the fuel and dont reduce the idle)

[fatmobile]

 More fuel flows at highway speeds.
 A clogged filter is worked harder,.. creates a higher vacuum.
  High vacuum "pulls" air out of the fuel. It looks like there is an air leak because of the bubbles in the fuel line.

 The higher the RPMs the more bubbles.

 If you have clear lines and a chance to look under the hood next time it happens, look for bubbles in the return line,.. maybe in the fuel input line.
 
 No air in the fuel would rule this out,.. a vacuum gauge on the fuel line would also let you know how hard the pump is pulling.

 Could also be a stop solenoid acting up.
 

[pitargue]

New fuel filter. Perhaps the new filter picked up a bunch of crap from sitting 4 months?

I'll try bumping the idle.

One thing I noticed, the hotter the weather, the more frequently this happens.  What I mean by this is the weather got a lot cooler lately, and it doesn't stall out all the time, just maybe 50% of the time.  Or maybe the bubbles are just getting worked out.  Weird.

But thanks for the suggestions.  I'll keep digging.  When I find out what it is, I'll post the findings.

[fatmobile]

Lots of things can restrict the fuel line and cause the same problems as a clogged filter.

 Clogged in-tank screen or stuff gathered up against a filter barb.

[pitargue]

Ah, more things to look at.  Thanks for the suggestion.

[745 turbogreasel]

Do you have a torque convertor clutch that isn't getting told to unlock?

[pitargue]

No. It's a transplanted 5 speed.  FN code.  Originally, the caddy was a 4 speed...

[8v-of-fury]

You might have internal pressure issues with your injection pump. If it is not able to maintain proper pressure it will not be able to physically pump the fuel to the injectors. The engine stalls at this point, If you just give it a blip of throttle or rest your foot on the go pedal does it stay running?

[pitargue]

You might have internal pressure issues with your injection pump. If it is not able to maintain proper pressure it will not be able to physically pump the fuel to the injectors. The engine stalls at this point, If you just give it a blip of throttle or rest your foot on the go pedal does it stay running?

Yes.

[8v-of-fury]

Yeah, so either the pump is not physically capable of producing ANY pressure which is hardly the case if it is still sucking from the tank..

So it would seem like you have a lot of air in the fuel lines making their way in to the pump and stalling it out.

Have you checked to make sure there is an "OUT" bolt in the the return line?? It will run with an "IN" bolt there, but cause your symptoms.