Thanks for the information, now let's see if we can figure this out, have you so far perform the following diagnosis?
1. Did you check for proper operation of the thermostatic air cleaner?
2. Did you Check for proper operation of the idle air control (IAC) system?
3. I know you told me you replaced the PVC, but did you check the PVC valve for proper operation?
4. Unplug MAP sensor. EMC will substitute a default value from the sensor signal. It stall and rough idle condition is eliminated, replace sensor.
5. Did you check the EGR system for proper operation?
6. Did you check for plugged or restricted fuel lines?
7. If engine starts, but then he immediately stalls, open distributor bypass circuit. If engine then starts, and runs okay, replaced distributor pickup coil.
8. Did you check for a weak spark from ignition coil?
9. You did not mention to me if you fueled up the day before it started?
10. Did you visually check vacuum hoses for split, Kinks and proper connections as shown on vehicle Emission Control Information label located on the hood of your suburban?
11. Have you checked ignition wires for cracking, hardness and proper connection at Both distributor cap and spark plugs?
12. Ensure fuel pressure is correct and all speed ranges, also check for poor fuel quality or water contaminated fuel.
13. Did you check to make sure the TPS is not binding or sticking?
14. And make sure the ECM controlled Idle speed is correct.
15. Make sure the air conditioner is not on when attempting to diagnose.
Now I know I have giving you lots to do, but I had the same problem with my 1990 Chevy Van, after making sure all of the above was checked out, in the end it was Fuel Pump inside the tank, and so I took advantage of the situation, replace the fuel filter, and rebuilt my Throttle body (the kit was only $12) it didn't look like it needed it but when I took it apart I'm sure glad I did, the base gaskets were no good and had some pretty bad vacuum leaks which was probably causing me fuel mileage, I did that some time ago and my van is still running sweet and giving me around 20 miles to the gallon, go ahead and check the list and eliminate everything you have already done, and let me know what you come up with.
Sunday, May 17th, 2009 AT 7:36 PM