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)

what are the ratings for the fuel pump pressure, flow rate, and fuel rail pressure? what is the TPI because i think i put a new one in?

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)

I already change the TPI

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)

there is no faulty code , their is no fuel filter any more but it ran fine with out one, i have some new plugs but i did just one side and i cant seem to find a vaccum leak but i will try to see if i can find one what is the best way to find a vacumm leak

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)