I'm putting here the current state of my '01 but not to ask for help. Not that I don't trust anyone's knowledge but mostly as an explanation to why these cars are not easy. I spend so much timing helping others on here while at the same time i've been dealing with my own troubles. I bought the car for $450 with 70k miles from original owner ( still under warranty) some big dents and heat warpage to interior.
Started off with a worn motor from lack of maintenance (but it did run for one night after doing these 4 repairs)
rusted out fuel pump from sitting for 2-3 years
alternator was done as it was the old style with big pulley
Needed a battery
bad MAF

In the past 1 1/2 weeks
-I rebuilt the block using Mitsubishi 3000 gt piston rings (yes it worked)
-Rebuilt the heads myself with new valve seals, cams seals
-Re-used some head gaskets which had 10 min of run time on them and sprayed with copper spray
After car got running.........
-it bogs when revving high and under loads, wont hold an idle after it gets really hot from driving around the block
-It's running lean so I sucked the gas tank dry as it was coming out yellow from the rust, then I scraped most of it out from the bottom of the tank and again found the fuel pump was rusting out and strainer was filthy. Put fresh 91 octane
-All this rust killed one injector, and the others had oil on the spray side from when the engine was burning oil So I swapped them all out.
-Fuel pressure was good the whole time but I swapped out the fuel pump for the one in the Accent(yes it works)
-Found and repaired 2 cut wires in the main engine harness which turned out to be ground sources for something
all in all spent 2 full days doing diagnostic checks like compression, timing, electrical pin out tests, sensor performance test
fuel pressure
-swapped in a spare PCM,APS sensor,Throttle body and re-initialized
-went as far as I could in the diagnostic process having only a generic scan tool to check sensor readings and after all this I can say it does run better now it is drivable but still bogs and eventually dies out at idle.
-I got to the point were I knew I had met my match and called my long time Hyundai friend but it's hopeless when the only codes being thrown are those for limp home valve being on.

The only thing left for me to try now is another MAF, Proper fuel pump, find someone with an XG300 so I can compar MAF voltage readings. I know the Hyundai scanner reads in .mv but my scanner reads in lb/hr so I hooked up my VOM and got a reading and it was'nt what the Hyundai scanner reads. It's reading low and doesn't change much with higher rpms which could explain why it's leaning out at higher rpm's. The old MAF does the same thing but at even a lower spec. I'm starting to believe I may have a restriction in my downstream cat as I allready check the manifold cats when engine was out. Would hate for it to be a exhaust restriction after all this but would also be glad it's fixed. So like I said i'm not asking for help just wanted to let you guys see that XG's can sometimes be very involved and why the independent mechanic does not like to work on these. If and when I figure this car out I will post my findings. As for now i'm leaving town and i'll get back to it next week.

well, l admire your patience with your car considering all the trouble its been, if it were mine l would more than likely set fire to it by now! lets hope it works out for you in the end

yeah i've always been known to have patience around cars. And since I bought this so cheap though in the end this car has cost me about $1200 but still a good deal. I just need a daily driver with 4 doors and i've always wanted a XG but never thought i'd have enough to buy one. The lady that sold me this could'nt get her engine warranty'd cause looks like she never changed her oil. She had it up for months and I was the only one to look at it twice. People tend to not realize that the 100k mile warranty is not as easy to use as it used to be when it first came out. Tough times have forced Hyundai to start asking for maintenance records instead of being so nice. I remember the times when it was pretty much up to us to decide whether we felt like warranty'ing a big job or not based on how busy we were.
But like I mentioned these cars and their ETC,MAF,EVAP problems will always keep this forum filled with "why is my XG doing this" questions. I wish I could be there to help everyone but then how would us techs make money. (IMG:style_emoticons/default/grin.gif) . Better yet I wish I could be there to make money off everyone! Hey now that's sounds like wishfull thinking. Anyways i'll update this thread next week with what I find and hopefully prove to myself that I still got it.Xg's dont scare me (IMG:style_emoticons/default/unsure.gif)

This post has been edited by mac1: Sep 19 2009, 01:54 AM

Well an update if you can call it that. Car has'nt changed a bit, no restrictions in both manifold cats (have'nt checked the downstream one), found the ETM manual for the '01 Xg is wrong and it actually should be more like the XG350 so I was thrown off course for a while. As it sits now it still sporadically dies at idle and lacks power so either I find another XG doner vehicle for testing or I go an unexpected route.....................
Because I want to a have cheap but luxurious car with room for 5 i'm gonna keep this car but give it the soul of a Sonata???
I know the European XG's have the 2.5 engine or so I think, I found out the chassis is the same all the way to the axles and transmission. I've proven this because i was able to bolt up a 2.5L engine block to a spare XG tranny i have and direct fit. I need a complete car with a 2.7L preferebly to swap over engine/harness/pcm/fuse box and whatever else I find when comparing electrical diagrams. The tricky part will only be getting the tach to work but it might not be that bad. You know even if I were to be able to fix this **** nightmare I still would'nt trust it on a long trip and with the 2.7L platform there is a lot less to go wrong. I'm gonna be tackling this next month after I move and have a garage to work in and find a wrecked '02 and up Sonata. Wish me luck.

thanks for the update, you have been busy. the XG's in central europe are a mixture of 2.5 and 3.0 liter models but the ones in the u.k. are all 3.0

good luck with the rest of it, keep us posted

FINALLY and update. after over a month of sitting I tired a couple more things to pin point the problem. First I disconnected the y-pipe to isolate the downstream cat thinking that it was restricted an still stalls and runs rough. Then I found some clean 89 octane in my fuel jug so I put it in a pressurized canister and fed it directly to the fuel rail after disconnecting the fuel pump and. Bamn! it runs like it should, revs like it should, I can turn the a/c on in D and it doesn't stumble and die. Sooooooooooo now i'm on the look out for a fuel tank as this one has proven to be more rusted out then I thought. I got a fuel pump out of a '01 Sonata I4 waiting to go in and hoping that a Sonata fuel tank will also work. XG's are extremely rare in junk yards, i've only ever seen one in person. I'm gonna call Hyundai and ask the part number to both models and hopefully they match. Woohoo.

Really good thread. I'm following with interest 'cause I have an '01 XG which was a salvage after a nasty front driver's side crash. I've had to do all of my work too, and like you, I'm a glutton for punishment.
I'll soon be dropping the fuel tank for a 'slow fill' issue, and was wondering if you had any pointers about tank removal. It looks like you've been through it a time or two...

Glutton for punishment is definitely how I would describe myself nowadays. It's good that you've been following this thread cause I have learned a lot and have typed everything here. Few weeks ago I pulled the gas tank out and decided to get it cleaned at a radiator shop($85), then put it back and was pleased with the results. But now it seems the last problem I have to fix has been here all along and I owe it to the donor engine I got from that parts car way back when. Turns out the reason i had to replace the piston rings on a extremely well maintained engine(I got all the service records from the glove box) was because the oil pump went bad(and I just bought an oil pressure guage out of suspicion) and after idiling for 5-10 min it would drop to almost nothing which triggered a chain reaction that went like this..........
-Engine warms up
-oil pump internally starts dropping in output pressure
-oil fails to get to the head to pump up the lifters
-valves fail to open because the lifters are not pressurized
-engine idle drops
-oil light comes on
-engine stalls

So now i'm waiting for the oil pump ($130 on ebay for a Kia Sedona), this should in theory finalize my troubles with this car and get it on the road. So to sum it up since day 1 of buying this car..........
-rusted fuel pump
-bad alternator
-bad maf
-bad turn signal switch
-no tachometer from shorted wires
-sludged up motor with 68k original miles!
-clogged injectors(oil and rust)
-donor engine with bad rings and 120k miles($550)
-replaced rings and upper gaskets($100)
-rusted fuel tank($85)
-dirty fuel filter($20)
-bad oil pump($130)............ awaiting results

If you think you have dirty gas tank like I did then first you'll need tall jack stands, remove the muffler and pipe from the cat back, disconnect the fuel pump from up top, disconnect as much of the hoses you see, start removing the straps(helps to have 19mm ratcheting wrench), once they are off the tank will shimmy out of place.
But a slow-fill will be something else I think. Do you mean that it is hard to fill your tank because the pump keeps stopping?

This post has been edited by mac1: Feb 6 2010, 03:22 AM

Wow. Impressive story. So... you've pretty much got a new '01 now, eh? Still liking it?


That's what I mean, alright. I did a visual on the canister and hoses that I could get to from underneath, but I'm thinking that I need to drop the tank in order to get topside access. You're saying that you disconnect the pump from up top before dropping the tank... what am I missing? I'm wide open.

yes disconnect the fuel lines and the connector on top of the pump. The tank has nothing that would cause a slow fill like in your case. All it has is a pressure sensing valve for emissions, anti syphon and the pump. YOur issue could be a canister close valve stuck closed not allowing atmospheric pressure in the system when engine is off. It's located in the canister deal and has inlet and outlet hose in a L shape. Take it out and apply + and - to it and look inside to see if it's stuck or sticking.

I did replace a lot of things on my XG, it's unheard of and outrageous. But all of it made sense in the end. I still haven't even put the new oil pump in, too lazy. I can do it in a days work but it's still a pain and now i'm going on a road trip all the way East. Wish I could take the XG but it's the Explorer's time to prove itself.

I'll check it. It's been a while since I looked at the canister, but I thought I had disconnected that vapor line and just capped it with a small-engine fuel filter just to keep crap out of it, and there was no difference. I could have gotten the wrong line. I didn't have my equipment, so I was just ducking under the car to make a quick attempt. I assumed that I would need to drop the tank to get to the pump connections and the filler tube up top. If I understand correctly, you're saying that I can get to the vapor line byh just reaching over the tank?

Now that I have a place with a level concrete surface and have the bulk of my tools here, I am needing to spend some quality time with my XG, and of course, it's raining and cold. Well, cold for Orlando. Which is kinda good, since the air conditioner compressor isn't spinning (another thread), but bad in that I can't get underneath the car without drenching. Anyway, while I'm snoozing underneath of the car in a week or few, I'll be wanting to take a look at that fuel situation. Like I said, I was thinking that I'd have to ease the tank down to get to stuff, so I'm happy to find that I may not need to do that.

Meanwhile, another question: Are you going to be able to change that oil pump without pulling the engine?

there is a fuel pump access panel under the trunk carpet behind the rear seats. Should have mentioned that earlier.
For the oil pump, the oil pan needs to drop and after I remove all the timing belt crap the oil pump kinda just sits there.

Oh, snap. Yeah, I think that redraws the picture for me. Is that a 'though the trunk' access thing, or a 'through the rear seat back' access thing? I guess it's pretty easy to find out.


Out of curiosity, do you need to remove motor mounts and jack up the engine, or does the pan drop ok as-is? Never done a transverse, myself, but I've done plenty of old V8s and inline-6s that required some jockeying around crossmembers and/or steering linkages.

well yeah on the XG you would need to removed front engine mount and put a floor jack under the trans to support it. Or use a engine hanger but that would get in the way of doing the timing belt. Then when the exhaust pipe is removed the oil pan is unbolted from the block but no need to remove the lower metal oil pan. This is there just to protect it from anything you might run over because if it was all alluminum it would crack. And as if I didn't de enough repeat repairs allready, this will be the second time I have to remove the oil pan on this engine. Last time was to replace the rings.

This post has been edited by mac1: Feb 26 2010, 02:35 PM

Note to self: When rebuilding or re-ringing an engine, replace oil pump.

and dont go to the dealer for it, buy it online for the Sedona OEM brand only and it will be stamped by Hyundai and Kia. Waaaaaaaay cheaper. And dont forget use the rings from a 3000gt also way cheaper.

http://info.rockauto.com/getimage/getimage...%200378060-1.jp XG exhaust manifold gasket

http://info.rockauto.com/getimage/getimage...MS95082_TOP.jpg 3000gt exhaust manifold gasket

what does a 3000gt have that we dont? BTW these are the same part number!! In this answer lies the future of my XG.

This post has been edited by mac1: Feb 26 2010, 06:47 PM