[dirich]

After taking my i30 into the mechanic today for diagnosis of an engine light on and car in "limp home mode"  on and off, I am told that it is most likely the fuel pressure valve or suction control valve. The limp home mode doesn't seem to happen until the engine warms up.      If anyone has had a similar problem that has been fixed I would love to know if they were able to source the part without having to purchase  the whole fuel pump. It has had the fuel filter air filter and oil filter and an oil change done.  I had this prob a few months ago and a new fuel filter seemed to rectify.    Someone suggested a temp sensor?  Thanks.

[tw2005]

After taking my i30 into the mechanic today for diagnosis of an engine light on and car in "limp home mode"  on and off, I am told that it is most likely the fuel pressure valve or suction control valve. The limp home mode doesn't seem to happen until the engine warms up.      If anyone has had a similar problem that has been fixed I would love to know if they were able to source the part without having to purchase  the whole fuel pump. It has had the fuel filter air filter and oil filter and an oil change done.  I had this prob a few months ago and a new fuel filter seemed to rectify.    Someone suggested a temp sensor?  Thanks.

No solution for you but what Ks has it done? My only thought at the moment is an engine swapover with some limp issue which we suspected a hose or vacumn hose left off. Up in Gympie I think, maybe @nzenigma has something inside his head he can rattle out

[tw2005]

do a search with "limp" there's a few old threads. hard to say but fuel filter seems to get a few mentions including brand and quality.


What's in yours ?

[tw2005]

2008 i30 turbo diesel not revving over 3000rpm

[nzenigma]

Hi guys,
Tw's link ( above) is referring to a bug produced by badly stored fuel. The filter sock that is described is in the unit under the rear seat. Easy to remove and the black deposits will be quite evident. So that's a starting point. Clean out, then use an overdose of a fuel treatment.
The suction valve will be available as a separate unit. Either here or from Korea. It sits on top of the high pressure fuel pump. On your model, it can be removed without removing the manifold. Its held on by three torx screws. The other item of interest is the pressure sensor. Looks like an oil pressure sensor. It unscrews from the fuel rail, it could be faulty or have bug gunk in it. If you talk to a dealer, the grubs will  try to sell you the whole rail. Not correct...Korea if need be.
Good luck.

[tw2005]

Hi guys,
Tw's link ( above) is referring to a bug produced by badly stored fuel. The filter sock that is described is in the unit under the rear seat. Easy to remove and the black deposits will be quite evident. So that's a starting point. Clean out, then use an overdose of a fuel treatment.
The suction valve will be available as a separate unit. Either here or from Korea. It sits on top of the high pressure fuel pump. On your model, it can be removed without removing the manifold. Its held on by three torx screws. The other item of interest is the pressure sensor. Looks like an oil pressure sensor. It unscrews from the fuel rail, it could be faulty or have bug gunk in it. If you talk to a dealer, the grubs will  try to sell you the whole rail. Not correct...Korea if need be.
Good luck.

what about ol mate up north with his engine swap? Was it Mike? DO you remember that one, I'm trying to as he had a limp issue with something left disconnnected?

[dirich]

Thanks - only other clue is that it seems to only go into limp home mode when engine is warm

[nzenigma]

what about ol mate up north with his engine swap? Was it Mike? DO you remember that one, I'm trying to as he had a limp issue with something left disconnnected?

Im not sure if Mike went to limp mode, but yes you are right, he had an extreme loss off power when hot...and yes, so-so mechanic was convinced that it was suction valve.
 Instead, we persisted with a hose break theory causing lack of suction, which stopped the turbo actuator from pulling in.
Mike had no MIL (light) or codes.
He eventually found that a vacuum hose was fractured.

[nzenigma]

@dirich , even though you are getting MIL light I would check the vacuum lines. When the turbo fails about 80% of your power disappears.
 Take top cover off the engine.
You will see several thin rubber hose lines (RH top side). Look for fractures especially where they attach to a valve or metal pipe.
When you go to "limp mode" get someone to rev the motor while you watch to see if the turbo  pulls on. One of the rubber hoses goes to the turbo actuator. If you put your finger over the end of the hose you should feel suction.

[dirich]

When i had this problem a while ago, a new fuel filter seemed to sort it.  We have changed the filter again (10,000kms) and it is a "Wesfil" type fuel filter which the mechanic assured me was reasonable quality.

[nzenigma]

When i had this problem a while ago, a new fuel filter seemed to sort it.  We have changed the filter again (10,000kms) and it is a "Wesfil" type fuel filter which the mechanic assured me was reasonable quality.

Do I get this chronology correct?
 You had Limp mode_ you changed filter_ problem solved_ 10,000kms later problem returned_ a 2nd filter (Wesfil) change does not fix problem?

If that is correct, lets assume for the moment that it IS the same fault...  Examine the fuel!
You need to get your hands dirty and lift the back seat swab. Using slightly more effort, remove the white plastic fuel pick up and examine inside the tank and gauze sock, (as per my post)

[tw2005]

Wesfil are usually the cheapest around, can't comment on quality. I have OEM and RYCO fitted with all mine , no issues with fuel

[nzenigma]

Logic dictates that we start at the beginning.
If he isn't getting sufficient fuel, no use blaming the bit half way down the supply chain,

[The Gonz]

Firty is going brilliantly even after her 15 months on stands fed a hibernating dose of Stabil in her full belly. At the time of getting her rolling again, I changed her oil, oil filter and air cleaner bits but left her fuel filter as was because it didn't seem as easy or simple as the rest.

Now at 116Mm, should I wait until there's a problem before changing it? I haven't checked but presume it was changed at her last logbook servicing a little before hibernation at 80Mm.

[tw2005]

Firty is going brilliantly even after her 15 months on stands fed a hibernating dose of Stabil in her full belly. At the time of getting her rolling again, I changed her oil, oil filter and air cleaner bits but left her fuel filter as was because it didn't seem as easy or simple as the rest.

Now at 116Mm, should I wait until there's a problem before changing it? I haven't checked but presume it was changed at her last logbook servicing a little before hibernation at 80Mm.

You just like brain teasing  , 116Mm, honestly what about the rest of us mere mortals 

[The Gonz]

You just like brain teasing  , 116Mm, honestly what about the rest of us mere mortals 

Why waste a perfectly good metric system with inadequate terms such as '25 mm', '100 cm' and '1000 km'?

[tw2005]

You just like brain teasing  , 116Mm, honestly what about the rest of us mere mortals 

Why waste a perfectly good metric system with inadequate terms such as '25 mm', '100 cm' and '1000 km'?

[Dazzler]

Just so you guys are aware this member is a female with I doubt much mechanical know how. @dirich (Dianne) I realise some of these suggestions may be hard for you to apply personally, but hopefully may be of some help to whoever is helping you sort this.

Feel very sorry for you after recently recovering from another expensive repair. 

[dirich]

yes, you have the chronology correct.  Had a similar problem earlier, no-one could find solution, so we changed the fuel filter and then engine warning light disappeared from dash (not immediately).  Now, the problem has recurred.  Firstly limp-home mode starts with no warning light, then warning light comes on.  I then had the mechanic service the car (as it was due) and he says cant find any reason so suggest changing the fuel filter (despite me telling him it was done 10000 kms ago) - I agree as he can't find any other solution.  Next day, same thing so return it to mechanic who does some more research and says that most likely cause is Suction control valve or fuel pressure valve.

We did take the advice given about checking the fuel sock and pulled out the rear seat to take a look but hubby was reluctant to go further as he didn't want to disturb the seal without having another on hand to replace if needed,but maybe we will have to pursue that.  Checked all hoses in the engine and couldn't see anything cracked or not connected properly.

Today when I drove it I also got some shuddering at 80kms (while still in limp home home)

[dirich]

Thanks - yes all is helpful as my hubby is pretty good with mechanics although isn't a fan of computers and these broad error codes that aren't real useful in finding the cause of the problem.

[Dazzler]

Thanks - yes all is helpful as my hubby is pretty good with mechanics although isn't a fan of computers and these broad error codes that aren't real useful in finding the cause of the problem.

Good luck with the checks. I feel your pain! 

[nzenigma]

Thanks - yes all is helpful as my hubby is pretty good with mechanics although isn't a fan of computers and these broad error codes that aren't real useful in finding the cause of the problem.

Thanks for coming back with your clarification. Hubby is basically correct, the error codes usually just send you off in the general direction.
For his info, the seal on the intake unit is quite robust and reusable. You need to push in the side tabs on the line connectors to release them. Fairly simple job.
To be honest, I'm relying upon the fact that a fuel filter has previously fixed a problem.
This may be an entirely different problem.
But if we stick with the original notion of fuel shortage, the mechanic has to check the fuel source ( sock in tank) and then work forward. We have had cases where the sock becomes blocked after driving for a while or even at a specific speed.
The suction valve fault is quite common in 'the trade', that's why mechanics are quick to blame it; but the Hyundai valve seems quite reliable. Ive not had a problem with one YET  , but have had failure due to organic gunk from bad fuel blocking the rail pressure sensor.

Good luck and stay in touch.

[dirich]

thanks - we are going to have a go at checking the fuel sock and will let you know the findings

[dirich]

we have removed the intank fuel filter - is it the mesh filter that we are looking at or do we need to pull the plastic assembly apart to check inside it?  Thanks again

[nzenigma]

sorry distracted. Its the mesh that should be nice and clean. Also shine a torch into the tank and see if there are small black bits floating about. If you have, or have had, bad fuel they are the result and will clog the mesh.

Think it is ok, otherwise you would have been asking about it,,,,hope

[dirich]

all done - mesh was quite dirty and there was a bit of gunk in the bottom of the plastic thingy.  Cleaned and back in so will see how it goes.  I guess if that is the problem the error code will clear itself?

[nzenigma]

The code may have been stored, so it needs a scanner to be plugged in to clear it. 60 second job for mechanic. However, disconnecting the battery for an hour could work. But make sure you have your radio access code. The ESP will light up, so drive car LH then RH turn. Ignition off, then restart and ESP light will be off.

I presume that the bottom of the fuel tank was clear of dirt? Hope so because it will get picked up again when the pump starts sucking . A bit of a tedious but worthwhile job, but you can syphon the rubbish out into a shallow container.

PS. The code can remain stored, but if a fault is no longer evident it should cease to cause limp mode.

[Dazzler]

Thanks for helping Dianne Guys, love your work!

Hopefully sorted, sounds promising. Also sounds like it needs a fuel additive for diesel bug maybe?

[nzenigma]

Yes should have mentioned that, Thanks Dazz 

[Dazzler]

Yes should have mentioned that, Thanks Dazz 

I think you or Gerard did earlier but not sure it was acknowledged.