Running Lean
#1
10-21-2009, 02:22 AM
Running Lean
Ive had my car (2002 Camero 3.8l V6 coupe) for about a month now Ive put 500miles during the time Ive had it on top of the 60k it already had. My check Engine Soon light came on a while back when i was doing well over 70 so I take it to Brake Max and i drop a new O2 sensor in it for $200 the lights gone and the codes have been wiped from the computer. An hr later i take it up to 90 this time light comes back on. So on a return trip i discover that when i hit 79 I start running lean and my engine temperature gauge is reporting 30 under what the engine really is. I am referred to my local Chevy dealer to check my catalytic converter and it turns out that its fine (105$) so now I'm left with a fuel pump which is running 10psi under what its supposed to. The pump is ($1200) to repair and i have to do some more testing on a temperature gauge.
Anyone one else have this problem with the engine running lean?
My friend told me that a car will suck all of the money out of your bank but man he needs to put more emphasis on that statement.
Anyone one else have this problem with the engine running lean?
My friend told me that a car will suck all of the money out of your bank but man he needs to put more emphasis on that statement.
#2
10-21-2009, 08:18 AM
Low fuel pressure results in engine running lean under load. $1200 for a pump sounds extreme. Engine running cold at high speed is probably due to a bad or missing thermostat, or the gage is wrong.
#3
10-21-2009, 12:34 PM
What would you recommend replacing becase i can floor it and the engine still jumps there is very little power missing if any but if i leave the car sitting around for at least a week its takes 3 tries to get it started.
#4
10-21-2009, 06:43 PM
The pressure regulator is much easier and cheaper to replace, so go with that first. You should test the regulator before replacing it. All you need is a FI pressure gage on the fuel rail. Let the engine idle and note the fuel pressure, pull the vacuum line from the regulator, if regulator is OK the pressure should increase by 5-10 PSI.
#5
10-22-2009, 12:25 AM
The pressure regulator is much easier and cheaper to replace, so go with that first. You should test the regulator before replacing it. All you need is a FI pressure gage on the fuel rail. Let the engine idle and note the fuel pressure, pull the vacuum line from the regulator, if regulator is OK the pressure should increase by 5-10 PSI.
Last edited by AbbandonZK; 10-22-2009 at 01:17 AM.
#6
10-22-2009, 11:00 AM
SES code for running lean could be either of the 2 o2 sensors or the mass air flow sensor.... you still might luck out... before changing pumphave you changed the inline fuel filter???? i had an ex girlfriends ford that acted like it was getting no fuel and a shop told her it was the fuel pump going out i replaced the filter and believe it or not car ran like a raped ape...
#7
10-22-2009, 10:46 PM
All the thermostat is supposed to do is allow your engine to heat up to a certain temperature. The t-stat is mechanical, not electronic.
#8
10-23-2009, 01:29 AM
SES code for running lean could be either of the 2 o2 sensors or the mass air flow sensor.... you still might luck out... before changing pumphave you changed the inline fuel filter???? i had an ex girlfriends ford that acted like it was getting no fuel and a shop told her it was the fuel pump going out i replaced the filter and believe it or not car ran like a raped ape...
#9
10-23-2009, 10:29 AM
hmmm for system too lean id honestly have to look it up but if the fuel pump could cause that i dont see why the filter wouldnt im just use to system too lean being mass air flow and oxygen sensor
#10
10-23-2009, 12:43 PM
Join Date: Oct 2007
Location: The 'Burbs of Chicago
Posts: 18,306
I wouldn't expect the filter to be causing a lean condition. An extremely dirty air filter would act like a choke, restricting air flow into the engine. Less air in the air/fuel mix = more fuel = rich. But then I would expect the sensors to be compensating somewhat, or maybe over compensating? Have you checked the air filter yet? I would have checked that before messing with the oxy sensor or fuel pump, especially since it's a free and easy check. You could have sucked up a neighbor's cat for all you know! 