Random loss of acceleration/dying at stop signs.

[19Accord97]

Hey All!
Not new to forums, but new to Hyundais. Anyways, my g/f has a 2003 Elantra with a 2.0. Recently we replaced the fuel filter, charcoal canister and whatnot to fix the problem of not being able to fill it up without the pump clicking and turning off. Now that works great!

However, lately her car will randomly decide not to accelerate and she will have to coast for awhile before she can get it to accelerate. Also, it will randomly die at intersections/stop signs and the problem seems to be getting worse.

I just put in a bottle of complete fuel system cleaner and plan on doing a Seafoam treatment (minus putting it in the oil) in the near future. On my Honda I use the brake booster line. As I am COMPLETELY unfamiliar with her car...letalone any Hyundais can you guys direct me where to do this? Pictures are always great! I've searched and checked out DIY's but didnt really see anything helpful.

With this in mind I am thinking either bad pcv valce or clogged egr? Again, ive cleaned the egr on my Honda but am clueless on this. Maybe crank sensor...hope not since ive never replaced one of those before.

The CEL is on and is giving an evap code. Has about 118k miles.

With this, the car was bought for $800 from a family friend because it got hit on the passenger side door...so not looking to spend tons of money. Just want to keep it running/reliable.

Any help or links to DIY's would be great! Thanks!

[Karrde]

The Elantra does not have an EGR system, so that's not your issue. I also wouldn't bother with the Seafoam treatment, but you could try cleaning out the throttle body with some plain old CRC throttle body cleaner. Also check all your vacuum lines and your PCV valve. Does the car run rough or have a rough idle? Or does it run fine and then just stop suddenly?

What exact evap code are you getting?

[fenixignition]

with that code im guessing theres a vacuum leak. i would look into checking the lines with smoke or something to see where its cracked. havent done that myself. but to answer your question about seafoam, i used the break booster hose. very simple process.

[19Accord97]

Thanks for the replies!

The Elantra does not have an EGR system, so that's not your issue. I also wouldn't bother with the Seafoam treatment, but you could try cleaning out the throttle body with some plain old CRC throttle body cleaner. Also check all your vacuum lines and your PCV valve. Does the car run rough or have a rough idle? Or does it run fine and then just stop suddenly?

What exact evap code are you getting?

She said it seemed to run a little better after I put the treatment in so who knows if it actually is or if it was in her mind. I plan on replacing the PCV valve soon but have read that they can strip out? Any suggestions to prevent that?

The car starts up fun, runs fine, and then just randomly begin to act up and not accelerate/die. This is what is confusing me. Hopefully not the fuel pump?

Again, not sure of the code since I wasn't

with that code im guessing theres a vacuum leak. i would look into checking the lines with smoke or something to see where its cracked. havent done that myself. but to answer your question about seafoam, i used the break booster hose. very simple process.

[avantegt]

My car has had similar problems, but mine were a combination of things.

I had a vacuum leak from a split hose running to my oil catch can and it would rev up to about 1500rpm then stall. Also the acceleration seemed a bit sluggish. Another thing was my crank positioning sensor had a large crack in it that would cause the car to shake and I would have to punch the throttle to get it moving.

[19Accord97]

The guy who scanned it thinks it was the "evap vp or the evap emissions system vapor pressure P105"

This makes it appear that the MAP sensor is bad. Could a bad MAP sensor cause the problems I described?

[Karrde]

The EVAP system has nothing to do with the MAP sensor. If the exact code he read was P0105, that indicates a problem with the MAP circuit so I'm not sure why he was telling you it was emissions related. Make sure your MAP sensor is properly plugged in with no dirty contacts and that the harness is not obviously damaged. Also make sure it's receiving it's 5v reference voltage at the connector. If that looks good, try replacing the MAP sensor.

A poorly functioning MAP sensor could certainly cause the problems you're describing.

[19Accord97]

The EVAP system has nothing to do with the MAP sensor. If the exact code he read was P0105, that indicates a problem with the MAP circuit so I'm not sure why he was telling you it was emissions related. Make sure your MAP sensor is properly plugged in with no dirty contacts and that the harness is not obviously damaged. Also make sure it's receiving it's 5v reference voltage at the connector. If that looks good, try replacing the MAP sensor.

A poorly functioning MAP sensor could certainly cause the problems you're describing.

Thanks for the reply! Is there a way to use a multimeter to test if the MAP sensor is working properly? I.E. What prongs would I test.

[19Accord97]

Drove it tonight to actually experience it firsthand. It did not accelerate twice during a 10 minute drive.

The first time it occured after going 55 for a shortwhile, i let off the gas, and when I went to accelerate it did nothing. Had the pedal to the floor and after 3 seconds or so it came back to life as if nothing happened. Second time I was turning into a subdivision and it did the exact same thing. Didn't misfire, buck, stall, or run abnormally.

Seafoaming and changing plugs tonight.

What wires do I use to test for the 5v? Thank You!

[Karrde]

Does your MAP sensor still have a 4 wire harness? If it's like my 2001, the MAP harness connector should have 4 pins. One is a 5v reference when the ignition is on, one is sensor ground, then one for each of your IAT and MAP signals back to the ECU. Sorry, I can't remember which is which :P

[19Accord97]

Yes sir, it is a 4 wire harness. Just ordered a new one for $25 versus paying $50 with my discount at an auto parts store. Doing all my research indicates the MAP sensor.

[Karrde]

For $25 you can't really go wrong, especially if you're getting a code indicating a fault with the MAP circuit. Let us know how it goes!

[19Accord97]

Yes sir, it is a 4 wire harness. Just ordered a new one for $25 versus paying $50 with my discount at an auto parts store. Doing all my research indicates the MAP sensor.

[19Accord97]

Sorry about the long delay....it took forever to get the part.

Anyways, installed the ebay MAP sensor (2 days ago) and the car continued to do the exact same thing. (not accelerating randomly and dying every so often when stopped). I went to Advanced Auto today and read the check engine light which was the oxygen sensors (p0134 and p0130). I don't think these were the same codes as earlier. So, I reset the codes/turned off the check engine light, drove across town, the car died, and bought another MAP sensor which was the same brand as the OEM one and installed it. On the way home it again did not want to accelerate two times but the CEL did not come on and is still off. So, i guess this rules out the MAP sensor.

I am completely confused. I doubt the primary o2 sensor would cause this and if so it should have lit the CEL agian.

Do you guys have any other ideas? Maybe the fuel pump itself? If it is a vacuum leak would the CEL come on right away? Also, is there a easier way to find a vacuum leak? Need to get this figured out ASAP.

[Matrixloader]

Sorry about the long delay....it took forever to get the part.

Anyways, installed the ebay MAP sensor (2 days ago) and the car continued to do the exact same thing. (not accelerating randomly and dying every so often when stopped). I went to Advanced Auto today and read the check engine light which was the oxygen sensors (p0134 and p0130). I don't think these were the same codes as earlier. So, I reset the codes/turned off the check engine light, drove across town, the car died, and bought another MAP sensor which was the same brand as the OEM one and installed it. On the way home it again did not want to accelerate two times but the CEL did not come on and is still off. So, i guess this rules out the MAP sensor.

I am completely confused. I doubt the primary o2 sensor would cause this and if so it should have lit the CEL agian.

Do you guys have any other ideas? Maybe the fuel pump itself? If it is a vacuum leak would the CEL come on right away? Also, is there a easier way to find a vacuum leak? Need to get this figured out ASAP.

those codes are for primary 02 sensor.
check the connection on the primary 02 sensor, its the one on the first cat, could be corroded and not making a good connection, disconnect the plug and look at the pins and see if its clean, sometimes water or crap can get in there and corrode the connector. if you have access to a good scan tool that can monitor 02 sensor activity i would use that to check it to see if its doing anything at all, maybe the 02 sensor is dead. if you have a test light you could check it to see if there is any power or ground going to it.

[19Accord97]

Well, i am just going to get a new upstream sensor and try that. It seems as though both o2 sensors have failed, however, the second one is there only to measure the emissions coming out of the cat for EPA purposes. Ill just use the spark plug defouler trick on that if I have to. Once i order and get the part i will update. Thanks again and feel free to post anymore ideas!

[19Accord97]

Put in the new o2 sensor. The 9 year old bolts on the manifold were a pain in the butt.

Took it for a test drive and it ran fine. When the lady drives it for longer trips I guess we'll see if it acts up. CEL is on so im waiting if it will turn off, or get it reset and see what happens.

[kawininja_81]

I was looking over this post for some help with my similar problem and wanted to comment to see if it helps us out.

My 2001 has been acting in a similar fashion but not as often as it sounds for you. FYI, I had a 0446 (code for evap sys leak) and a 0110 (IAT sensor failure). I replaced the MAP/IAT sensor (you know for 2001 its in the same unit), and cleared the codes. After driving about 10 miles, had a stumble and check light came back on. This time i got 0105, MAP sensor failure... annoying.

This was a brand new MAP sensor that is supposedly failing, therefore i think there is more to it than that, I.e. the evap problems causing the MAP failure, not the sensor itself.

Maybe this helps, but i will have to work with it more to figure out exactly whats going on.

[19Accord97]

Good luck! It is a pain!

From what I was told, the CEL went off and the car did not act up on a 30 minute trip. This happened after we seafoamed and changed the plugs on a hour trip and then the problems returned. I am hoping the o2 sensor will fix it! Will update when I talk with them later.

[19Accord97]

Looks like it took care of the problem!

Never thought an o2 sensor would cause such problems since I have had ones go bad before. Hope this helps someone!

BTW, I bought the sensor off of eBay brand new for $39 shipped. The brand was Standard.