1991 Chevy Lumina

Hi there,

Start with a scan test, checking for a possible problem with a TPI sensor, also check fuel pump pressure and flow rate, get a fuel rail pressure test done, start here.

Mark (mhpautos)

Hi there,
The TPI, is the throttle position indicator or sensor, located at the throttle body, as for the fuel pressures& flow rates, I will have to re post as I don't have access to that info on this computer.

Mark (mhpautos)

Hi there,

OK, have you done a scan, just in case there is a fault code logged. And check the usual things, if you have not already, fuel filter, all tune items, vacuum leaks.

Mark (mhpautos)

It's a bit of a worry that you're not running a fuel filter, the injectors may be affected with all the muck in the fuel, you will be surprised how much rubbish your filter will catch. To check for a vacuum leak, you can use a length of hose and use it as a stereoscope and listen around the manifold gaskets and vacuum ports, you should hear a leak.

Mark (mhpautos)