Hi,
The white smoke sounds like it is backfiring. Is there any reason to think there could be a timing related issue?
Here is a link that discusses similar issues:
https://www.2carpros.com/articles/engine-backfires-while-running
Also, have you checked fuel pressure to make sure the regulator is working and pressure isn't too high? Here is a link that explains how it is done:
https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator
Here are the manufacturer's specs for pressure:
1988 Chevy Truck S10/T10 P/U 2WD L4-151 2.5L
Fuel System Pressure Specifications
Vehicle Powertrain Management Fuel Delivery and Air Induction Fuel Pump Fuel Pressure Specifications Pressure, Vacuum and Temperature Fuel System Pressure Specifications
FUEL SYSTEM PRESSURE SPECIFICATIONS
FUEL PRESSURE:
Ignition ON Engine OFF .................... 62-90 kPa (9-13 psi)
One last thing. If you haven't already, check to see if there are any diagnostic trouble codes. This truck has an OBD1 system that doesn't require a scan tool. All you need is a short jumper wire or even a paper clip. Here is a link that explains how to test for codes. Also, there is a list of codes and their descriptions after the directions.
https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method
_________________________
Let me know what you find.
Joe
SPONSORED LINKS
Tuesday, July 14th, 2020 AT 8:41 PM