Unsure of whats causing an issue (Hyundai)

[wwmnw]

The Hyundai forum is about as lively as a morgue so thought I'd ask here.

Bit of a strange one, not sure if its electrical issue or not. Sometimes the car feels likes its misfiring, kinda like its stuttering (if a car could do that) when accelerating usually under 40 mph mainly 2/3/4th gear but has been small issues in 5th at a little over 40 mph. It doesn't happen all the time and can happen when the engine is warm or cold.

Just changed the spark plugs from NGK R BKR5E (were on the car when I got it) to some Bosch Super 4 as recommended by euro car parts, idles better but on first test drive it actually performed worse. Felt better coming back via the A1 and opening it up a bit.

It appears to have had some kind of service before I bought it as the air filter is clean and new looking the ignition leads look good and new, spark plugs did look iffy hence the change and there was verrry little oil in it, only other thing I can think of is fuel filter but I cant find it, guessing its under the car and its a low sitting car so hard to see under.

[Jonesfach]

Fuel filter. Especially if it's a diesel.

what car? Engine?

[millworm]

Fuel filter. Especially if it's a diesel.

what car? Engine?

Has spark plug so not a derv

[wwmnw]

2002 Hyundai accent 1.3 petrol I'm told the engine code is G4EH, I am thinking fuel filter but I cant find the thing to check must be underneath but I cant get far enough under to check without a jack (which I haven't got)

The randomness of it is whats got me puzzled, it doesn't do it all the time.

[millworm]

Park one wheel up on the kerb and wiggle under. It's probably by the tank. Would be obvious if it's been changed or not.

[brucer]

Misfire under load will be the coil pack or leads.

[wwmnw]

Park one wheel up on the kerb and wiggle under. It's probably by the tank. Would be obvious if it's been changed or not.
Can just see around the tank and not so long back fixed a leak, didn't spot it but then again I wasn't looking for it, I'll give that a go though cheers.


Misfire under load will be the coil pack or leads.

Leads look new, was thinking coil pack too as its not often they are changed. They're not usually cheap either so hope its not that lol

[meritlover]

Lambda sensor

[wwmnw]

Post cat is new decent one, no codes on code reader either.

[meritlover]

thats inconclusive.

[wwmnw]

Well the big issue is with it not showing any codes its not giving any clues to what the issue could be and I bought a code reader as when I got the car the check engine light was on and it needed an air flow meter and post cat lambda.

As I suspected its probably ignition leads/coil pack or fuel filter, they are the only logical things it could be. Was hoping for a more informed opinion as there are some very experienced and good mechanical types on here (which I do feel I've got) feel free to throw some suggestions.

One other thought I had was coolant temp sensor, the car gets to the halfway hot mark in less than a mile and is diabolical on fuel but this seems common from what I've read (only costs about £30-35 to fill up at 99.9p p/l so has a tiny tank) doesn't help that it has 113K miles on it, but hey its Korean and just a temporary run about, albeit an expensive one ffs lol

[mowgli]

Injectors need cleaning?

[meritlover]

Thats the problem with reading codes to determine a fault.
if the pre cat lambda was faulty the mixture would be false and therefore make the post cat lambda read out of range until it wrongly highlighted it was at fault. chances are it was probably ok and something else was influencing the mixture such as the MAF or the pre cat sensor, pin hole leak in the exhaust etc...

[dan23]

Sticking egr valve maybe

[ShawnAzzopardi]

I think the filter is inside the tank, on the pump if I'm not mistaken.

[wwmnw]

Injectors is possible with it having over 113K miles on it. Meritlover I get what you're saying, after changing the AFM and post cat lambda (and clearing codes) it felt great but occasionally this weird thing would happen and its really starting to bug me what it could be lol

Never thought about EGR, would it cause this kind of symptom? Shawn yeah guessing it must be in tank, been meaning to check it for ages lol

[dan23]

Egr will give similar symptoms
not sure how difficult it is to remove on Hyundai s
remove an soak it over night

[wwmnw]

Bigger issue at the moment, brake pedal hit the floor last night turns out the pipe that runs from the reservoir and through the suspension turret has cracked. Wonder if its anything to do with it running through the turret.