94 4.3w stalling only when warm and idle.

[duke350]

I have a friend who has a 94 blazer 4.3w and he has a problem with it. I am trying to help him via internet and telephone. He has limited test equipment. When it is first started it runs great. Fuel pressure at first key on is 61-63, right in that area. When first started it is 55 at idle, until taken on the road, then its back up to 61-63 and stays, even at idle. No leak down at all, little to no fluctuation. Blazer runs great at 10 MPH or at 90 MPH. The problem is when it gets warm it will sometimes stall at idle. No codes, no fuel pressure fluctuation, just stalls. It will at most times start right back up, sometimes it will take holding the key a few seconds longer, but it will always start. Does anyone have any ideas? He has very limited test equipment and cannot get here for about a month, so I am looking for things he can do himself.

[Rick Norwood]

Originally Posted by duke350

I have a friend who has a 94 blazer 4.3w and he has a problem with it. I am trying to help him via internet and telephone. He has limited test equipment. When it is first started it runs great. Fuel pressure at first key on is 61-63, right in that area. When first started it is 55 at idle, until taken on the road, then its back up to 61-63 and stays, even at idle. No leak down at all, little to no fluctuation. Blazer runs great at 10 MPH or at 90 MPH. The problem is when it gets warm it will sometimes stall at idle. No codes, no fuel pressure fluctuation, just stalls. It will at most times start right back up, sometimes it will take holding the key a few seconds longer, but it will always start. Does anyone have any ideas? He has very limited test equipment and cannot get here for about a month, so I am looking for things he can do himself.

Similar to the problem with my 93. It would start up and run like a scalded dog but would stall and die when it got warm but it wouldn't start up again until it cooled off. My problem was the ignition control module inside the distributor. Everyone tried to tell me that they either work or they don't, and heat has nothing to do with their performance, but I put in a new one for $35 USD and the problem went away.

It is fairly simple to replace, remove the distributor cap, and the mounting screws for the module and CAREFULLY unplug the wire connectors (they will break) take good notice of the location and orientation of the wires etc. Once out of the distributor, some parts stores like Autozone can test them before you buy a new one.

I actually have had to replace mine twice same symptoms both times and same results both times.

[ericn1300]

Originally Posted by Rick Norwood

Similar to the problem with my 93. It would start up and run like a scalded dog but would stall and die when it got warm but it wouldn't start up again until it cooled off. My problem was the ignition control module inside the distributor. Everyone tried to tell me that they either work or they don't, and heat has nothing to do with their performance,

Autozone has a test bed that heat stresses the ignition module, if you suspect it just pull it and get it tested.