alero troubles [Archive] - Forum


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01-11-2013, 06:32 PM
i have an 02 alero with a 2.2l ecotec engine last week it started idling rough while in gear, runs fine in N or driving. showing no codes. i changed the fuel filter, spark plugs and boots. i heard it might be the fuel pressure regulator does anybody know how to test it. thanks.

01-12-2013, 06:23 AM
Could be a dirty MAF sensor or dirty injectors also. Try running a bottle of fuel system cleaner next time you fill up (I like the chevron techron stuff, but almost anything will do). You can buy a can of MAF sensor cleaner at the auto parts store.

To check the fuel pressure, you'll need a fuel pressure test gauge. You can get a kit with the gauge and hoses and fittings for about $45, or you might be able to rent one from the auto parts store. There should be a test port with a schrader valve on your fuel rail somewhere (probably under a black plastic cap). The test kit hose should screw right onto that. Put some paper towels around it 'cause some fuel will come out before you get it tight. After it's on turn the key to on but don't start the engine, and check the pressure. It should go up to somewhere in the 40's or 50's (V6 grand am's are around 50 psi) and should stay steady and remain there for several minutes without dropping. Then start the engine and see what the pressure is. It should fluctuate much once the idle settles down.

01-12-2013, 07:07 AM
^ Definitely do like Aaron suggested, what I'd add onto that is seafoaming the engine. I've done it twice and seen improved idle and smoothness in the engine's performance.

Right from their website:

To clean deposits from the tops of cylinders and the backs of intake valves, add 1 oz. Sea Foam to each gallon of fuel. Sea Foam will slowly re-liquefy the deposits.

To remove deposits more quickly, Sea Foam can be induced directly into the combustion chamber via the following method. Since Sea Foam contains Volital Organic Compounds make sure this method is approved by the state in which your planning to use it. With the engine warmed up and running, SLOWLY POUR 1/3 to can of Sea Foam down the carburetor throat or into any main manifold vacuum line that DISTRIBUTES EVENLY TO ALL CYLINDERS. Note that some newer induction systems, like those found on Vortec and Subaru “H” style engines, do not have any vacuum line that distribute evenly. Consequently, this process should only be attempted by technicians with a comprehensive understanding of the engine’s induction system or use Sea Foam Spray through the throttle body (discribed in a different section of this web site).

Once the product has been applied, turn off the engine and allow the Sea Foam to heat soak for a minimum of 10 minutes. At this time, Sea Foam will dissolve deposits. After allowing the Sea Foam to soak, restart the engine in a WELL VENTILATED AREA as exhaust will be extreme for a short time. Drive aggressively for 2 to 5 miles to allow all the atomized deposits to be safely expelled from the system. REPEAT SEA FOAM TREATMENT AS NECESSARY.

Performing a Sea Foam Engine Treatment on a Fuel Injected Engine:

Begin by parking the vehicle in a well ventilated area. Locate a vacuum line that you are certain DISTRIBUTES EVENLY TO ALL CYLINDERS. On many vehicles the easiest option is taking the vacuum line from your brake booster PCV. (See notes about special situations such as the Vortex or Subaru H style engines.) If you are not certain, contact a certified technician.

Start the engine. For automatic transmissions, keep the car in PARK. For manual transmissions, put the car in neutral and apply the parking brake. SLOWLY POUR 1/3 to can of Sea Foam Motor Treatment into the vacuum hose, while at the same time revving the engine to about 2000 RPMs. You will begin to see clouds of white exhaust from the tailpipes. When you have finished pouring, turn off the engine and let it sit for at least 10 minutes.

Now start the vehicle again. Drive it aggressively (but legally) for about 2 to 5 miles or until the white smoke is no longer being produced. REPEAT SEA FOAM TREATMENT AS NECESSARY.


In addition to this, you can also keep the car in park and keep the RPMs around 2000-2500 and let the seafoam burn off that way, but it'll take longer and you'll have the infamous smoke show. lol that's what I do for ten minutes THEN drive for five miles to burn off the excess.

01-13-2013, 03:27 PM
thank guy's i will try these. i will let you know.

01-18-2013, 06:57 PM
ok i tried all theses things and still idles weird i will try to test the purge valve next, strange it idles rough about 80% of the time. when stopped at a traffic light 30second then runs rough.

01-18-2013, 07:01 PM
This could also be a possibility, check for a vacuum leak. Most of the time a vacuum leak does trigger lean troublecodes, but not all the time. Check to see if you're having leaks somewhere between the throttle body and the intake manifold. There's also the PCV line that goes to the rear valve cover, maybe that's leaking or could be clogged/broken as well.

Just a thought.

01-23-2013, 06:25 PM
thanks i will try.

02-01-2013, 06:09 PM
well solved the problem finally. it was the vapor purge valve solenoid, took it off and could blow through it, its should be closed/off at idle. only cost $25

02-01-2013, 06:36 PM
Glad you got it fixed!!!

02-01-2013, 06:57 PM
well solved the problem finally. it was the vapor purge valve solenoid, took it off and could blow through it, its should be closed/off at idle. only cost $25

Had a feeling it was connected to a vacuum issue. Glad you got it fixed.

Don't be a stranger around here, though. We have plenty to keep you entertained around here. lol

02-02-2013, 08:16 PM
That's weird. Usually a 44x code will set with a stuck EVAP part. It's good you found it yourself, though; that would've been an absolute no-code nightmare in a shop: you would've spent lots of $$ in diag and the tech would've lost his ass, not mention the service writer stuck in the middle...

02-04-2013, 08:39 PM
thanks guy's