Not going to assist in your DX but that compartment sure seems like it was very wet, even for an 11 year old car.........hate to say the death knell, was it in a flood zone or a washed title?

Best of luck, I hope Bayer's on sale this week^_^

 

Interesting thought... while I've seen written warnings of this I didn't even think of it when I bought the vehicle...There's not been a whole lot of flooding here in Michigan in the last 10 years. Pretty sure the PO was from MI but... :mellow:.

While there is no CEL on, can having it scanned help?

CEL has come on recently (more than once) and it's been scanned as a bad fuel cap, and cleared.. but that's all that came up.

 

Grey plastic TPS... new part is black.. Wild guess.

Have you even scanned for DTC ?

PCM and TCM updates available to bring it up to last version of software.

Been issue with Tucson where roll up to stop, it stall... start right back and drive away.

 

Hi,
I think the car was sold because of this mysterious problem. You got it now.
Also the maybe new sensors etc. seems to me they were struggling with it too and could not get it fixed, so they simply sold the car, so it's upto you to solve it now.
One item several times popped up on the forum with also mysterious concequences like stalling randomly was the fuel tank.
It seems the fuel tank inner lining / paint seems to flake off after many years, so clogging the in tank fuel pump filter. Obviously when the engine is running the pump pulls the particles and flakes onto the filter. When engine stalls and sitts for a while the particles/flakes could fall off again and "everything is ok".
So I would check the internals of the fuel tank, be it a bit of a hassle to get it out or opened to flush it and clean.
Good luck,
Paul

 

I have not tried that johnaauld ... I will when I can.

Thanks for the reply paul03. Yes and yes... I was thinking of going to the fuel pump filter next and now I will.

I also need to change the plugs and wires as I've no idea how old the existing ones are.

 

I commented on your other post (ride on the towtruck) about checking the fuel pressure regulator to see if it's leaking. Just wondering if you looked into that....

 

I would take a hair dryer and start heating up various components under the hood and see if it causes it to stall. It sounds like it's a heat related issue, where something gets heated up to the point where it looses it's electrical circuit and won't work until it's cooled down enough for the circuit to close again. Could be a relay, a crank sensor, the fuel pump, anything that would directly affect either ignition or fuel delivery. I could simply be due to old plugs. If they have worn the gap out to far, the flame could be blown out by compression. Not a bad idea to change them if they are due just to rule them out.

My initial thought though is that it's a heat soak related problem. Make sure the fuel lines aren't getting too hot from being close to exhaust either, you could have fuel that is boiling inside the lines ( vapor lock ), which is less likely, but something to be considered since it would start but not run ( which means you had fuel and spark, but not enough of one to keep it running...I lean more towards fuel initially.

When it would start but not run, how smooth did it start up?

 

There is an evap air filter that can get plugged with sand etc, can cause evap codes and drive ability issues.

It is located in the wheel well where fuel tank inlet line is on the élantra; not sure on the Santa Fe, but it shouldn't be hard to find.
Creates problems during refuelling quite often.

 

Thank you all... It gives me some hope.

I picked up some new plugs and wires and will be installing them today.
And then I'll move on to the other things mentioned.
I also got some "SeaFoam" to run through it.

My budget is tighter than a @#$%!. so this repair maybe a little drawn out.
Non the less... I'm determined to fix it!

 

Changed the plugs, wires, and the plenum gasket as well.
Everything went very smoothly thanks to this great write up...
Hyundai Santa Fe Spark Plug replacement on a V6 Cyl

The old plugs center electrodes comes to a sharp point. The gap on them was still about .044.

It's all back together and running well...
so I guess it's just a matter of driving now till (if) it dies again and go from there. :mellow:

 

an update... About 200 miles so far and it's still running...
While that's nice... I still don't believe the plugs and wires are the cause of the random stalling. I'm still driving with my bicycle in the back.

 

And the story goes on.
After about 500 miles of it running well since changing the plugs and wires,
yesterday, halfway home (15 miles) it stalled out on me again... in rush hour... bad.
Luckily I got it parked.
Came back the next morning, started it up and drove it home.


Okay so ... the symptoms when it shuts down, I can see now are consistent.

After running fine for a lot of miles, and about 30 seconds to a minute before it stalls...
I feel ever so slightly, a chop of loss in power. Like it wants to die but only for a millisecond. Barely noticeable unless your really paying attention. And then several seconds go by... and then again but barely noticeable.

It'll do that a couple of times until it finally just starts to whimper and slow down... (quickly find a place to pull over) then stopped it idles low and uncertain for about 15 seconds or so... and finally shuts down.

It can be started up a few seconds later but won't respond well to the throttle. Little to no power to even put it in gear.. and then dies. Try that a few times and it won't start at all. Cranks over just fine but won't fire up.


Let it rest a day and it runs.


I'll be trying some of your recommendations as soon as I can.

 

I've had fuel pumps sound a lot like that.

 

I've had clogged fuel filters sound just like that too.

 

Oh how I'd love to say "BINGO" right now....

I found what I believe could cause the problems I'm having but ... well ... look

Under the seat, through the trap door...

Lot's of rain last night.. and wow look at all that moisture in there!
And hey what's that? a poorly repaired exposed wire!

When I found it as you can see it had been taped by the PO.
The tape however had slid down the wire and there was nothing but a little bit of wet grime hiding the copper.

 

Update...
After finding the frayed wire and before unplugging...
I started it up (running fine as it should) wiggled the wires to see if there was any effect and there was none. Still running fine. Then I unplugged it and it died just a second later.
Cleaned up the wires, covered the exposed ones, a little dielectric grease plugged it back in... made sure everything was clear. Started it back up again and then .... it ran like crap and stalled... hmmmmmm. Unplugged, checked the connections, plugged back in, rechecked everything, started it, ... running crappy then stalled UGGHHHH...
So then I took the butt of a big screw driver and knocked on the top of the tank/fuel pump there thinking maybe that might shake some crap out of the pump or filter.
Fired it up and it ran great.

So while the frayed wire could have been the cause it appears it was not.
Next up then is to get in there and look at the pump and change the filter.

Called the local auto parts store..
The said the filter is integrated with the pump.. $70
And then the "strainer" is $15
Does that sound right?

Sidenote:
Been unable to get the manual online... so I just ordered a Haynes from Amazon... so that'll be nice to have.

 

Update...
After finding the frayed wire and before unplugging...
I started it up (running fine as it should) wiggled the wires to see if there was any effect and there was none. Still running fine. Then I unplugged it and it died just a second later.
Cleaned up the wires, covered the exposed ones, a little dielectric grease plugged it back in... made sure everything was clear. Started it back up again and then .... it ran like crap and stalled... hmmmmmm. Unplugged, checked the connections, plugged back in, rechecked everything, started it, ... running crappy then stalled UGGHHHH...
So then I took the butt of a big screw driver and knocked on the top of the tank/fuel pump there thinking maybe that might shake some crap out of the pump or filter.
Fired it up and it ran great.

So while the frayed wire could have been the cause it appears it was not.
Next up then is to get in there and look at the pump and change the filter.

Called the local auto parts store..
The said the filter is integrated with the pump.. $70
And then the "strainer" is $15
Does that sound right?

Sidenote:
Been unable to get the manual online... so I just ordered a Haynes from Amazon... so that'll be nice to have.

Price sounds about right. Just remember to transfer some things to the new pump or it won't start. I think it's a gasket, that won't be apparent. I'll try and locate a link that talks about that. Here is the link:

http://www.elantraxd.com/DIY/fuel.php

This is for an elantra, but I think it might help. And don't over-torque the bolts when you put it back in.

 

Thanks for the link...
I got the pump out and it looks pretty clean...
as does inside the tank.. (a little bit of debris from around the cover fell in there)

It's not clogged at all in any way that I can see...
is there a way to test it?

Very likely though... it could be the original pump...
I suppose I should just replace it anyway to eliminate that as a probable cause to the problem.

Ordering the pump.

 

Upon closer inspection... somebody was definitely in there before.
I realized a couple of the screws had been stripped out before me...

Also ... the seal around the plastic part that holds the pump is a little bit manky.
Could a bad seal there be the problem? I haven't ever smelt fuel.

 

Picked up a new pump ... now just waiting for the heavy rains (with tornado warnings) to pass...

 

I can't see bad gasket causing pump to cavitate or get air locked.

Pay close attention to where the O rings are located when you are removing old pump from sending unit; pump won't pressurize properly if they aren't in right place. The élantra pump guide mentioned is a good reference.

The stripped screws can be replaced with a slightly larger sheet metal screw.
As long as gasket is compressed a bit it will seal ; wrecked screws are common in salt belt areas.

Measuring fuel pressure during no start condition would have been useful; but when pump heats up clearance increases and pressure drops, possibly the problem you are having.

 

Yes I would have liked to measure the fuel pressure but I'm quite limited by my lack of special tools and workspace (parking lots) Also... the "no start" condition was so occasional and intermittent, the timing just didn't work out for me to test it.


Anyway...
The fuel pump has now been replaced.
Still runs so that's a great start. Ha ha no pun intended.

It could just be my optimistic imagination but...
the pedal/acceleration feels more responsive...
A bit more power?
Due to a bit higher fuel pressure?
... Yeah I've got a good imagination lol...

I only hope now that it stays running.

 

Could be the old pump did have a lack of power to put enough fuel through the system and maybe it now and then died in the proces, stalling the engine.
So maybe this new pump does give better pressure so more fuel in the cylinders so more power to the engine and will keep running.
Did the new pump also come with a new fuel filter attached?
Good luck,
Paul

 

I hate to tell ya...

From what you describe, it doesn't sound like a fuel problem. It's highly intermittent, it doesn't care if it's hot or cold, and can go many moons without a incident. That's an electrical problem.

From your pics, the motor doesn't look particularly dirty, but looks like a fair amount of corrosion going on. If it was my car, I'd make sure the negative battery cable ends are clean, particularly where the grounds bolt to the body. Really common problem to have all sorts of weird electrical gremlins because the ground connections at the body get corroded. Take the ground off, clean the paint from the body, reattach, etc.

 

The "Strainer" as they called it was sold separately.. $15

Jsinton ... I do agree in that it sounds like more of an electrical issue.
But changing the fuel pump was easy enough to do, and I got to see the condition of that part of the system... and now it's done. Eliminated as the possible problem at the very least.

I will not simply wait to see if stalls again though...

I will surely be checking and cleaning those connections.
Thanks

 

Reporting back ... about 500 miles since changing the fuel pump and it's still running well.

I'll also say again that the acceleration response is (still) noticeably better than before.

 

Glad it seems ok; more power more pressure maybe. Not many people have access to the right adapter to measure is so sometimes on himikage vehicles it's worth the chance.

 

Several thousands of miles later... still starts, keeps running, and runs great!