[Gordon]

Ok, 91 astro AWD... I've changed every sensor except the TPS and the main computer and it still idles rough (rough enough it shakes your brain while your sitting at a light). It will occasionally stall but only going into reverse.

Above idle it still runs great and pulls hard with no oil burn or black smoke.

I also changed the injectors, map sensor, knock sensor, coolant sensors, egr solenoid, cleaned the egr itself (wasn't really dirty).

The van only has 250,000 kms on it so this is really tickin me off.

Put a new wire set, new plugs, new cap & rotor, checked the timing, replaced all the vac lines.

Not sure if it's related but the cruis control doesn't work either but has great vacuum going to it.

I was gonna do a V8 swap but I can't get the mounts for a reasonable price or find a good set of plans.

This is our daily driver and hauls our 4 kids around so if anyone has any ideas please let me know.

 

[davesyo]

What about the IAC (idle air control valve) ? If it's dirty it will cause a stall or rough idle . I usually remove it to clean it and at the same time clean the throttle body

 

[Gordon]

cleaned the original, didn't change anything at all so i bought a new one... still no change

 

[davesyo]

Does it seem to be worse when the engine is warmed up ? If so maybe it could be a faulty ignition module.Any codes ?

 

[timelessbeing]

With the engine idling, spray short bursts of carb cleaner around various areas of the engine. Do the engine RPMs go up at all?

 

[gtkane]

Does it blow black(or dark) smoke at idle, or does it have a rich exhaust smell(that really stings your eyes)?

 

[davesyo]

One more thing I forgot . could be a faulty torque converter clutch solenoid

 

[Gordon]

Warm or cold it runs the same.

No codes.

Sprayed with carb cleaner... no vac leaks.

The only smoke i ever get is the cold startup blue cloud.

Would a torque converter solenoid also make it idle like crap in park or neutral?

 

[timelessbeing]

Are you losing any coolant? Does the motor stumble when you give it some throttle?

 

[Gordon]

No leaks and no stumble.

Compression test shows 140-145psi on all 6 cylinders.

Once you pound that pedal down she takes off like a bat out of hell and pulls strong to 6000rpm without missing a beat.

If someone happens to have a set of AWD V8 mounts to sell or plans top make them let me know... i have a 350 sbc lined up already for $300.. it's a 1994 tbi motor already pulled for me

 

[timelessbeing]

Well if airflow isn't the problem, then perhaps it's fuel delivery. How is the pump/filter? I've heard about problems with injector spider assemblies and poppet valves as well.

 

[Gordon]

Pumps working but i have not pulled it out of the tank to look at it.

Filter has been replaced.

You'd figure if it was a fuel issue that it would also be starving for fuel in higher rpm's, not just idle.

The spray pattern is a nice clean cone also, no drips.

This one is TBI so no spider assembly in it.

Keep the ideas coming maybe we'll hit on something :confused1:

 

[Gordon]

ARG... now i have a code 45 today... O2 sensor rich.

Stupid thing is only 3 weeks old... i'm gonna blow this van up soon :cussing:

 

[timelessbeing]

That means the fuel-air mixture isn't full combusting right? Maybe the ignition module suggestion was right on.

 

[Gordon]

Changed it when i did the cap and rotor.

As I said I have replaced almost every sensor and part on this POS van.

I'm so tempted to put a brick on the gas pedal and let the v6 blow :devil:

 

[timelessbeing]

This may be more trouble to you than you're willing to take, but you could hook up realtime OBD analysis. It's not a terrible investment.

 

[Gordon]

Where would I find this item?

 

[davesyo]

I was gonna suggest hooking up a scan tool , the mention of a OBD analysis I guess is meant to be the same thing

 

[Gordon]

I had a friend throw his Snap-On scanner on it today and everything shows normal :banghead:

 

[davesyo]

Was it a scan tool that gives you live data or just a code scanner ?