Expert: Robert Summers - 7/12/2008

Question
I have a Chevy Astro, 92, that while driving, suddenly stalled and has been running rough ever since.  I was able to limp it to a friend's house where I changed plugs, wires, cap and rotor and it acted the same.  I found I could keep it running if I continually pump the gas pedal so I drove it home.  There I changed the fuel filter, air filter, PCV valve and EGR valve with the same results.  I can hear the fuel pump kick in and looking at the TB, I can see the injectors squirting fuel. I've inspected the vacuum lines and they all look ok, I get a strong vacuum at the EGR, cruise control, etc.

Luckily so far I've only changed things that needed to be changed but I haven't narrowed down the problem. While it's running, there is no check engine light so I'm at a loss at what to check next.

Answer
Hi Gnuorder... surging and stalling is not always a fuel problem...check the ign module, bad coil, do you have enough fuel pressure. do the inj have a nice even cone shaped spray when running...if not maybe plugged up injs...try a good inj cleaner..if you have good inj spray and fuel pressure i would tend to lean toward the ign problem....hope this helps