The car wants to stall at idle after driving 2 miles when starting from cold. I had to keep the engine revs high at stop lights so the engine will not stall, the car has manual transmission.
I thought I had cleared this problem up 6 months ago...replaced spark plugs and cables and replaced fuel filter and cleaned behind the spark coils and cleaned the 4 mounting bolts that mount the coil towers to the engine block for better ground connection, air filter is clean and the gasoline is fresh.

Had po341 error code for the misfire 6 months ago but now I got just the EVAP po441 code...checked for vacuum leaks and did not find any.

I heard that the intake manifold gasket can have a fold by cyl. 1 on these 1.9 liter 4 cylinder engines and air gets in and leans the fuel mixture but that seems fine when i did the propane gas tank test.

 

ECM will trigger this code when it detects that the vacuum level in the Purge System is not within the proper specifications.Indeed the intake manifold folds and gets partially sucked in to number one.

p0441 is the following:


If the vacuum sensed when the EVAP purge valve is commanded open is not within spec, p0441 is thrown.

There are multiple possible causes including a bad purge valve, a purge valve getting hung up, wiring issues.......

You may indeed also have a very very slight vacuum leak somewhere that is dropping the overall vacuum in the vehicle just enough 2 throw the required vacuum level in The Purge line out of kilter.

I would carefully inspect the purge valve and the electrical connections as well as the purge line and the evap canister to make sure they are not damaged.

 

Have you ever given the throttle body a good, thorough cleaning? Just a thought.

 

I still suspect a vacuum leak once the engine has really warmed up, It could be that infamous intake manifold gasket by cylinder nr. one.

 

Yes I did clean the throttle body just recently, it was not very dirty....cleaned the PCV too for good measure.

I did an idle speed reset and the idle runs a bit higher than before and ran the car just a short distance and it ran OK.....but I need to drive it for a couple of hours steady in city traffic to see if it is a fix....kind of a risky thing to do if it is not a fix.

 

Hmmmm, I'm not familiar with that code. Maybe check the o-ring on the gas cap. Sometimes you can remove them and clean them along with the cap and filler neck and take care of an EVAP code that way. I just don't know if it's THAT code.

 

I did clean the gas cap and the filler neck but to no avail.

Right now I got bigger fish to fry with that Saturn, as a brake line rusted out and lost braking, so I am working on replacing the brake lines and the brake hoses.

 

If you are keeping the car I would do all the lines. If one rusted through I would expect the others are not far behind

 

Yes, I am doing all the lines and replacing the flex hoses going to the front disc brakes and back drum brake wheel cylinders.

Does anyone know the thread size of the fitting for the master cylinder that feeds the line to the front left disc brake?

It is sized a little bigger than the other ones on that non ABS master cylinder.

 

Consensus after wandering through Rock autos site is that primary is m11, secondary is M12. FYI, this is the same regardless of whether the car has abs or not.

All listings for master cylinders had m11 and M12, a few of them primary and secondary listed backwards. One listing said m10 and m13. The t-test tells me that is an outlier.

I'd include a screenshot to prove my point but that would mean 14 screenshots and contrary to the belief of others regularly on this site I do have a life.

Not all the listings include the tech specs at the bottom. The information I provided is from the listings that do. The original AC Delco part is not available for sale or I would have just looked that up. Please confirm this information before spending money on something regarding the information.