2003 Sudden Stalling

[michail]

My girlfriends 2003 Protoge5, 2.0 has started stalling suddenly. She has had it happen a few times while idling and just applying gas from a stop. When idle it just dies or almost dies and recovers. When just applying throttle it shutters and stalls. She has been able to restart and continue driving. It seems to occur more within about 10-15 minutes of driving. We are in Florida so the air temps are warm.

I replaced the plugs and coils, cleaned air filter, and replaced valve cover gasket, it was leaking into one of the spark plugs (a coil was on that one, which was replaced) and seafoamed the engine. I also found the oil filter was loose and leaking. However, the stalling is still occurring.

There is no CEL and I haven't had a chance to scan for codes. The idle feels smooth and consistent to me. Which may rule out any vacuum issues. Power feels good on throttle too, no hesitations. So the car runs great until it doesn't.

Does any of the above point to anything that could be the culprit? I'm a bit more familiar with VWs.

I'm going to try cleaning the MAF and IAC valve next.

 

[orange pro]

Try cleaning the maf and plug on connectors my moms p5 does that after I washed her car Engine etc...

 

[michail]

Do MAF issues cause these cars to stall? On the VWs it usually just results in a CEL.

I've seen MAF mentioned a few times in searches but it usually didn't wind up being the cause. The air filter was really dirty so it's possible it needs a clean.

Is the MAF the inline plastic box just behind the filter? I see several other sensors along the intake as well.

 

[pcb]

I would be more inclined to check and clean the IAC,.. When the car is idling, the IAC controls all the fuel air mixture. It could be gummed up.

If your air cleaner was dirty then replaced, that could throw off the ECU's learned settings and it may need some time to readjust.

Check for vacuum leaks and cracks in your intake tube.

If your battery was recently disconnected, then the ECU needs to relearn the car and it runs like crap while it learns.

Did you run any Seafoam through the brake booster vacuum line?? (that can help to clean the IAC and other valves)

 

[michail]

I'll check out all those things and report back. I'm disconnecting the battery when working so I'm guessing that should reset the ECU.

Should any of the other sensors along the intake be checked/cleaned? Going from memory now but it looks like there were about 3 or 4 sensors in the intake tube.

 

[pcb]

After I disconnect my battery, my car runs REALLY rough at idle and very nearly stalls. It take a good 100 miles for the ECU to relearn how to idle the car.

The MAF is located right on top of the air box, behind the plastic screen. It's fast easy and cheap to clean (use the proper CRC MAF cleaner to be safe and DON"T touch the sensor with the spray tube)

 

[michail]

Oh yes, I did run the seafoam through the brake booster. I had the air filter off for a clean and re-oil after I ran that through. So it sat for a while before dropping a smoke bomb on the neighborhood.

 

[kms1990]

i agree it could be a dirty maf sensor, if the filter has been dirty for awhile then it is very likely the maf got dirty. try cleaning it as mentioned above. at same time i would also take out the intake tube and clean the throttle plate and iac (hole near top of throttlebody opening inside tube opening before throttle plate) (stick your finger in and feel you can feel the hole) its most likely very dirty as well. go ahead and change the pcv valve as well, it can cause idle issues as well. (its the black thing with a hose connected to the back middle of the valve cover) also check your intake tube for rips(these cars get that problem alot) if so autozone or other parts stores in your area should have it available it was $30 here from autozone. if none of this helps then i bet its a sensor failure or a vacuum leak(spray carb cleaner on hoses if idle changes then you have a crack and a vacuum leak), could also be a wiring issue.

 

[pcb]

Oh yes, I did run the seafoam through the brake booster. I had the air filter off for a clean and re-oil after I ran that through. So it sat for a while before dropping a smoke bomb on the neighborhood.

Apparently, you're supposed to be really careful when re-oiling your filter to make sure that there isn't too much oil on it that can blow off the filter and contaminate the MAF,...

I'm still thinkin your ECU is still learning,... Make sure you give it that 100 miles to learn with lots of chances for it to attempt to idle the car properly,... It needs to practice with all different air and engine temps.,...

 

[michail]

Thanks for all the great advice everyone! I was thinking of doing the PCV too. I'll get all the above done and let it adapt.

I did two light coats of oil and gave it several hours to absorb. Hopefully that won't be the problem.

The girlfriend is a bit panicked, she thinks the car is self destructing but I'm sure it's something simple.

 

[pcb]

I'm pretty sure that it's best to keep your foot off the gas while it's struggling,... I assume that as soon as you hit the gas (because you think it's gonna stall) that attempt to idle the car is negated and it has to try again until it gets it right,...

You obviously don't want it stalling in traffic but if it's safe to do so, it's probably best to let it figure it out on it's own,...

When the battery is disconnected, the ECU follows a MAP that was set up for optimum at the factory with a brand new engine. Our cars are now 13 years old and a lot of our settings have drifted off from factory new and the car can really struggle to get it back to running order.

 

[michail]

I think the last time it caught her by surprise when pulling out of a parking space. It happened twice in the parking lot upon applying throttle. Then it was fine for the rest of the drive. The other times have been at red lights.

 

[pcb]

If it's stalling "as" she applies the throttle, there may be a different problem,... but I'd still wait it out for that 100 mile period,..

 

[michail]

I replaced the PCV valve. The old one seemed to be gummed up with oil. The car must think I'm the mechanic because it won't stall for me. It feels great for a car of it's age.

Wow, it's nice working on Mazdas after VWs. You can get parts at the autoparts store and they cost 1/10th the amount.

 

[michail]

Oh, also I noticed that the hydraulic line from the brake was rubbing up on the back of the intake. It looks like it's dented in but I don't think punched through.

Here is a picture, sorry, OneDrive doesn't allow direct image links. https://onedrive.live.com/redir?res...uthkey=!ABqbSi6ISqoldNY&v=3&ithint=photo,.jpg

I'll try to reseat the intake a little lower.

 

[kms1990]

may have made a small hole. every time i have my hood open i look for anything touching that tube because how easy it rips

 

[MaxPower]

To properly inspect that air intake accordion tube, you really need to take it off the car.

Is the problem intermittent? If so, the EGR valve is also a possibility.You can test that out by disconnecting it and seeing if the problem goes away.