Help!!

[92_CB7]

Alright heres the deal, its not on a cb7 but its on my other daily driver (a Kia Rio ) but anyway, it's idles rough, and won't surpass about 4 grand on the tach and therefore it won't go any faster then about 60 km/h and even on its way to that speed it bucks like crazy, and if i rev it up from idle and let it drop to idle, it will stall. i have replaced all the filters so i know its none of those, but i can't seem to figure out what it is. my check engine light flashes on and off from time to time, comes on when its bucking, and goes off when it stops. the car will run great sometimes, but then others it does this. please i need to figure out what this is, i have had it to the dealership and on their machines to check and see what codes its throwing and they can't find anything wrong with it at all. in 04 they had a fuel issue but mine got excused from it and i still can't figure out what it is. Thanks for your responses in advance.

[SwiftCB7]

wish i could help i dont know anything about kia rios... manual or auto???

[92_CB7]

It's a manual, and yea i don't blame you, its a piece to get into, but i got it for free so i took it. i just wish i could ifgure out whats wrong with it.


and its the 1.5 hyundai motor that was in the elantra until like 00 i think.

[SwiftCB7]

have u checked any of the vacuum lines??? since it stalls??? just an idea to check on...

[92_CB7]

yea i checked them, and like tis got all new filters, ignition components and all that, but i forgot to mention, that while it does this, its got a misfire on 3 and 4. but it only happens sometimes. and even when i got ignition on all four cylinders, it does this!!!

[Leung]

check the timing?

[92_CB7]

to my knowledge, the timing is fine. Is it possible the mass air flow sensor would cause this?

[92_CB7]

Please, can anyone help me? i need to figure out what is wrong with it, so i can fix it and sell this piece of shit.

[Losiracer2]

does it have the oil in the spark plugs issue like our CB7's have? maybe oil is fouling the plugs and not causing enough spark or no spark in those cylinders?

[92_CB7]

No. i just changed the plugs maybe three days ago and they were dry. i have tried a lot to figure this out. and i am still stumped. thanks for the help so far, and keep the suggestions coming cause i am outta ideas.

[deevergote]

Check a Hyundai site... www.hyundaiperformance.com is really good, I'm a member there.

[92_CB7]

Thanks a lot Deev, you really know your cars, not too many ppl i have talked to knew it was made by hyundai.. i will check it out.

[92_CB7]

by the way, there is a meaning to this problem, and it is NEVER BUY A KIA!!!!

[js593]

You say its having issues on 3 and 4? Swap the plugs from 1 and 2 and put the 3 and 4 into 1 and 2, see if the issue is in 1 and 2. Check for spark after, make sure its getting fuel.. etc..
go through the same shit we do on our cb's, check all the normal stuff.

[92_CB7]

i just put al 4 new plugs in a few days ago, and switched them up. and still no luck. i've gone through all the normal stuff, checked my vacum lines and no leaks or anyhing that i can see. i plan to take it into work on thursday YET AGAIN to see what can be found, i am gonna do a compression test and all the fun stuff to just for the hell of it. but someone also suggested my crank sensor? would that or the mass air flow sensor be the problem?