A flashing check engine light usually indicates a misfire. You need to check codes to know possible causes.
That REQUIRES an ENGINE SCANNER to do that.
I have the check engine light on and the code is for map sensor on my 1999 1500 Chevy suburban
See link below.
The engine computer has detected a malfunction and set a code.
The 1998 Chevy Express 1500 Van could have the 4.3, 5.0 or the 5.7 engine.
The crankshaft sensor is located in the engine on a Chevy 1500 truck. This is under the hood.
5.3
Where does the vacuum line lead to from the top of an 2002 Chevy express 1500 van with 5 liter engine
35- idle air control (iac) valve/ circuit
The EGR valve on a 1994 Chevy 1500 is located on the top of the engine. If the valve becomes stopped, the engine could idle rough or stall.
The 1998 Chevy Express 1500 Van could have the 4.3, 5.0 or the 5.7 engine.
That requires an engine scanner.