2001 Impala LS need fuel pressure specs.
ck_1500
04-01-2010, 06:52 AM
Does anyone know what the fuel pressure specs. are for a 3.8 engine in a 2001 impala.
I'm trying to fix a hard starting when hot issue and fuel mileage has dropped off. My pressure is 48 psi. whith key on engine off, 53 psi with engine running and vacuum line removed from regulator and 43 psi when engine is revved up. I'm thinking my fuel pump is failing, since car has 130,000 miles on it, and pump has never been replaced. Regulator seems ok. Any help would be appreciated. Thanks Lenny.
I'm trying to fix a hard starting when hot issue and fuel mileage has dropped off. My pressure is 48 psi. whith key on engine off, 53 psi with engine running and vacuum line removed from regulator and 43 psi when engine is revved up. I'm thinking my fuel pump is failing, since car has 130,000 miles on it, and pump has never been replaced. Regulator seems ok. Any help would be appreciated. Thanks Lenny.
Airjer_
04-01-2010, 10:52 AM
41-47 psi. Does fuel pressure drop with the key turned off? If the pump where going bad you would notice something other than a drop in fuel economy.
ck_1500
04-01-2010, 12:37 PM
I'll have to check and see if pressure drops when key is turned off, didn't check that. Car is hard starting sometimes when warmed up, not alway though, and when it starts it seems flooded and has to clear it's throat. It also has a slightly rough idle at times when in gear, waiting at a light. I used fuel injection cleaner, with not results. I might change the fuel filter again and see if that helps. I have about 15,000 miles on tne filter.
Airjer_
04-01-2010, 12:50 PM
If fuel pressure doesn't drop than I would be more suspicious of the MAF sensor. The last three months or so we have replaced several for different driveability complaints. A quick view of engine data with a scan tool may give you the clues you need to narrow down the possibilities.
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