[darthvader5000]

hi everyone . I have 2004 Accent Petrol. Have a strange problem. Everytime I get a full gas tank my car's engine shuts down on declutching ( whilst changing gears , idling etc) . The moment the petrol level falls below the F mark , everything becomes alright. I took it to the Hyundai Authorised service centre in Mumbai and their head works guy said it was something to do with the vapour flow of petrol which i could nt figure out and didnt quite believe it. To fix it he removed a pipe from under the hood ( coming out of the firewall centre section upperside just below bonnet hinge) , which goes into a kind of a valve. He said once fuel level drops , refix the pipe. To my amazement it worked and does so even now everytime... Anyone knows what the problem is and what to do ?

[darthvader5000]

Folks i was searching around and from a site i got this ...

Question: 2000 Hyundai Accent 4 cyl Front Wheel Drive Manual 121,000 miles when the car is filled above half a tank it has a rough idle it occasionally stalls but is ok when under half tank. I removed the spark plugs and it appears as if its running rich. any help you can give would be appreciated.
Answer: Have the fuel evaporative system checked-from charcoal canister / purging solenoid all the way to the fuel tank if okay-get the fuel pressure check.

So can anyone explain what the Q&A above mean ? And do they relate to my car , if yes , what do i do ?

[SS-Traveller]

Originally Posted by darthvader5000

hi everyone . I have 2004 Accent Petrol. Have a strange problem. Everytime I get a full gas tank my car's engine shuts down on declutching ( whilst changing gears , idling etc) . The moment the petrol level falls below the F mark , everything becomes alright. I took it to the Hyundai Authorised service centre in Mumbai and their head works guy said it was something to do with the vapour flow of petrol which i could nt figure out and didnt quite believe it. To fix it he removed a pipe from under the hood ( coming out of the firewall centre section upperside just below bonnet hinge) , which goes into a kind of a valve. He said once fuel level drops , refix the pipe. To my amazement it worked and does so even now everytime... Anyone knows what the problem is and what to do ?

IMHO as a first instance, check and replace the engine and gearbox mountings if necessary. The engine's sitting lower on its mountings than it normally should and is moving when you press the clutch pedal. So everytime you declutch, the vapour return pipe gets kinked and partially blocked, causing the ECU to shut down the engine. This becomes a more acute problem since when you top up, the vapour return pipe remains immersed in liquid fuel, and the vapour has to bubble through and get back to the tank.

Or try not to completely fill the tank everytime...

EDIT: The fuel evaporative system is the vapour return system. Do you have a low mileage problem? I should think not... Also, removing the return pipe solves the problem, so the pipe is probably getting kinked or choked somewhere...

[darthvader5000]

hi

thanks for your reply.
First the engine shuts down only when fuel is topped up, the moment it falls below the F level. This problem of engine shutting during idling / declutching to change gears is completely gone. So for now i have removed this pipe and it works fine and when the fuel level falls below the FULL mark i will re connect the pipe, since the engine shutting down does not happen at below F levels. Just spoke to the Hyundai dealer , he says the charcoal cannister system needs to be replaced. Cost about 6.5K He says , blowing through or cleaning doesnt work. is that true.

b) another thing. At below half levels is fuel tank , the engine stalls to low rpm and one has to floor the accelerator to get it to pick up, then ease up on the foot to let it continue as normal. Have had the injectors cleaned but to no avail. Had the fuel pump motor changed but still no change. Could the two problems be linked? since one appears only at below half tank and one only above fuel tank.

thanks

Note from the Team-BHP Support Team : Please take the time to use proper punctuation as per Team-BHP rules. Avoid...typing...like...this. Thanks.

Nope i dont have a mileage problem, get about 8.5kpl in city driving ( colaba , mostly 3rd gear /4th gear ) with ac on.

EDIT: The fuel evaporative system is the vapour return system. Do you have a low mileage problem? I should think not. Also, removing the return pipe solves the problem, so the pipe is probably getting kinked or choked somewhere.

[SS-Traveller]

Originally Posted by darthvader5000

Nope i dont have a mileage problem, get about 8.5kpl in city driving ( colaba , mostly 3rd gear /4th gear ) with ac on.

8.5 km/l looks like low mileage IMO, though I'm not too familiar with the Accent Petrol. Other members please advise.

The fact that the Accent has a charcoal filter means the car has a returnless fuel injection system. But I'm sceptical about the charcoal canister failing - it is generally fail-safe, and there is nothing in it that can be blow-cleaned either. More likely problems from what you describe, are
(i) a problem with the charcoal canister tubing or purge control valve; or
(ii) a problem with the fuel line pressure sensor - most likely.

Get a second opinion before you spend 6.5K and more...

[Jaggu]

Originally Posted by SS-Traveller

The fact that the Accent has a charcoal filter means the car has a returnless fuel injection system. But I'm sceptical about the charcoal canister failing - it is generally fail-safe, and there is nothing in it that can be blow-cleaned either.

failed in my iKON if its the same thing that was replaced in my car, i have posted with pic long time back

[SS-Traveller]

Originally Posted by Jaggu

bill related to the work:
Parts
1143722 Cannister 878.68+109.84 tax
1356020 Hose Fuel Vapour 469.69 + 58.71 tax (look at the image below, if thats the tube they are talking about then, i was RAPED!!)

Labour
Hose - Fuel line connecting removal and insta 75 + 9.18 tax
Cannister - Evaporative Emission - Removal and Inst - 75 + 9.18 tax
Diagnosing charges 750 + 91.80 tax

Originally Posted by Jaggu

failed in my iKON if its the same thing that was replaced in my car, i have posted with pic long time back

Hi Jaggu: OK, took some time to find your old post - that's the canister indeed. It's just a box / canister containing activated charcoal, which absorbs petrol fumes from the fuel injection lines and the tank, so preventing atmospheric emission of petrol vapours. Present in a "returnless" petrol FI system. There's a pipe with a purge valve attached to this canister, so when your engine needs the fuel, the vapour is "sucked back" into the system.

Most problems occur when the pipe kinks or the purge valve goes bust. That pipe looks flimsy, but is a high pressure pipe, so it can be expensive (plus it's a Ford!) - as a result the system runs too rich, and FE goes down too. And yes, we presume the same problem with darth's Accent. But 6.5k sounds like through-the-roof pricing for a Hyundai.

But diagnosing charges of Rs.750+taxes??? You went to a motor garage or to the doctor??? Never heard this before...

[Jaggu]

go through the entire thread and you will know why they charged so much and gave me a heart attack first, suggesting an engine job!

[SS-Traveller]

@ Jaggu: Yes I did go through the whole thread, and I lost quite a lot of confidence in Ford's training programme for it's dealership mechanics. But diagnosing charges?

[darthvader5000]

hi SS ,

Is 8.5 /litre with ac on 3/4th gear actually low?.. anyone else has an input on this please ?

Anyways, for another opinion went to the HM plaza workshop and there the guy was quick to catch on [IMO :-) ] He restarted the car , revved it and checked the suction of the purge valve. He mentioned that it kicks in only at an RPM of 3000 and found it ok. Then he opened my filler cap and we heard a low pop cum hissing sound. Closed the filler cap. Re connected the pipe ( which i had removed) to the purge valve. His diagnosis : both the problems ( with below half level fuel , engine stall at low rpm AND with above F level engine shut down at idle are being caused by the charcoal cannister which he said needs to be opened and cleaned or replaced OR/ AND the fuel vent pipe fitted above the fuel tank which could be blocked for which he needs to take the tank down and check it out.It's these two things which were starving the engine of fuel supply which was causing these two problems. So he's asked me to come when fuel level is low to avoid wastage.

When i questioned him with some internet readup facts/jargon [:-)] , he said it was these two parts because a) the symptoms b) purge valve working fine c) the pop cum hissing sound when he opened the filler cap.

Cost of replacing he said was approx 1.5-2K plus labour and taxes.

Comment anyone ? Would appreciate.

Originally Posted by SS-Traveller

8.5 km/l looks like low mileage IMO, though I'm not too familiar with the Accent Petrol. Other members please advise.

The fact that the Accent has a charcoal filter means the car has a returnless fuel injection system. But I'm sceptical about the charcoal canister failing - it is generally fail-safe, and there is nothing in it that can be blow-cleaned either. More likely problems from what you describe, are
(i) a problem with the charcoal canister tubing or purge control valve; or
(ii) a problem with the fuel line pressure sensor - most likely.

Get a second opinion before you spend 6.5K and more...

[vikram_d]

Originally Posted by darthvader5000

hi SS ,

Is 8.5 /litre with ac on 3/4th gear actually low?.. anyone else has an input on this please ?

8.5 kmpl for a petrol Accent is low. My uncle's car with 100% AC usage give 10 - 11 kmpl in the city.

[Jaggu]

Originally Posted by SS-Traveller

@ Jaggu: Yes I did go through the whole thread, and I lost quite a lot of confidence in Ford's training programme for it's dealership mechanics. But diagnosing charges?

You can call it there charges for taking the scanner and running multiple scans + compression test etc keeping the car in garage for 2-3 days while scratching their heads!

Originally Posted by darthvader5000

hi SS ,

Is 8.5 /litre with ac on 3/4th gear actually low?.. anyone else has an input on this please ?
-------------
When i questioned him with some internet readup facts/jargon [:-)] , he said it was these two parts because a) the symptoms b) purge valve working fine c) the pop cum hissing sound when he opened the filler cap.

Cost of replacing he said was approx 1.5-2K plus labour and taxes.

Comment anyone ? Would appreciate.

Diagnosis is correct, cost reasonable = go ahead with the job. FE might improve a lil bit in certain cases, since this contributes to rich mixture (my iKON showed these symptoms when plugs were checked).

Mumbai 3/4 gears 9-10 with ac is aok.

[SS-Traveller]

Originally Posted by darthvader5000

...the charcoal cannister which he said needs to be opened and cleaned or replaced OR/ AND the fuel vent pipe fitted above the fuel tank which could be blocked...

Originally Posted by Jaggu

Diagnosis is correct, cost reasonable = go ahead with the job.

Hi darth, you got your answer. If the valve is working fine, then a choked canister and/or choked vent pipe is the culprit. HMP has good engineers, I'd trust them more than I would a dealer's half-trained mechanics. And HMP's estimate came to 1.5-2k, which is a lot better than 6.5 at the dealer. So, as Jaggu said, go ahead.

Let us know whether your mileage improves once the job is done. IMHO it should.

[darthvader5000]

It's the second day that the car is at the HMP workshop today. They have so far found a faulty two way v/v inside the fuel pump which has been replaced. The charcoal cannister has been replaced. The injectors and throttle body have been re cleaned. But apparently the problem is still there. So am still waiting and meanwhile the bill seems to be rising by the hour

Originally Posted by SS-Traveller

Hi darth, you got your answer. If the valve is working fine, then a choked canister and/or choked vent pipe is the culprit. HMP has good engineers, I'd trust them more than I would a dealer's half-trained mechanics. And HMP's estimate came to 1.5-2k, which is a lot better than 6.5 at the dealer. So, as Jaggu said, go ahead.

Let us know whether your mileage improves once the job is done. IMHO it should.

[darthvader5000]

OK the job is done . Just drove the car back. Changed the Cannister @ Rs 2387/- plus VAT , Valve Assy -Fuel Cut Solenoid @ Rs 311/- plus VAT , Valve Assy -2 Way @ Rs 521/- plus VAT.

In addition total labour for these three was Rs 306/- plus ST. Other labour incl fuel pump cleaning @ Rs 115/- , Fuel Injector Cleaning @ Rs 235/-

Car drives absolutely fine. SS am going to check on the mileage and post it the moment I am done doing that.

Have attached the pictures of the three parts so that others can have a look at what they are. The valve on the left is the two way valve and the one on the right is the fuel cut solenoid.

If one blows through the 2 way v/v , air comes out fine one way but when blow through is done from the other end , the air flow is not continuous but with stoppages.

cheers