I've got a '95 blazer with 113500 miles on it, and recently it has started acting up. It'll take about 15 seconds of cranking before it will actually start, the mileage dropped off from 19 mpg to the last tank was 13.5 mpg with no change in driving habits. It also is idling rough when cold, and seems to take even longer to start when cold. I replaced the throttle position sensor about a year and a half ago, and I've checked the computer with a snap-on mts 2500 scanner and it came back clean. If anyone has any ideas what might be causing this I'd appreciate it.

Thanks,

ksubenny

Do you smell gas in your cab while/when you start it?

could be your CPI unit or fuel pump. check those

It does smell rich when i start it up, and I've checked both Oxygen sensors, and they both seem to be acting properly.

If it smells rich and your gas mileage has dropped you might wanna check your spray pattern on your CPI. I have a similar problem with mine and I have not been able to fully diagnose my problem but it has come down to I need to check my fuel pressure should be around 60 PSI with key on from what I have seen in this forum and if it isn't the fuel pump than most likely the CPI unit. It may be dirty or just may need replaced fully. I usually opt for replacing thigns in my vehicles when I have the money.

More than likely the CPI... Pull the plenum and check for signs of washing. (where one side is cleaner than the other) If the passenger side is washed it's your CPI, if the driver's side is washed it's your nut kit. (Though if you replace the CPI, replace the nut kit). IF both sides are dirty then test the fuel pressure at the shrader valve, but being it's bad gas miledge, it's more than likely the CPI.