Omega Owners Forum
Chat Area => General Car Chat => Topic started by: TheBoy on 02 March 2014, 21:24:47
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Little Bro's car. We've been chasing a fault with this since he got it. Basically, it usually idles rough as hell, and at higher RPM, feels like its holding back.
LTFTs are at -12.% at idle (as low as they will go on this car), occasionally flagging a "Too rich" code.
When cruising, LTFTs raise to about -4%
Lamdas replaced, as old ones were looking a tad lazy. MAF replaced with a 2nd hand part, exactly the same readings as the original (within spec, but at the lower end of said acceptable values). Throttle Position Sensor reads slightly lower than what the internet implies at idle. New plugs as a matter of course (and other service items)
Oddly enough, he has never been able to change the fuel filter - he has tried several times with various filters from ECP and dealer, it never starts, until he puts original back in.
I've told him to go measure battery and charging voltages, but otherwise running out of ideas...
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Er, have I missed what car?
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Er, have I missed what car?
Hyundai, but not sure that makes a difference ;D
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Er, have I missed what car?
Hyundai, but not sure that makes a difference ;D
Ok, have it your way. ;) ;D
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Er, have I missed what car?
Hyundai, but not sure that makes a difference ;D
Ok, have it your way. ;) ;D
Me no understumble :-\
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No comment..........
Strange as no other filter will work apart the original 1 fitted .
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No comment..........
Strange as no other filter will work apart the original 1 fitted .
Yeah, we're wondering if some bodge was put on it to make it run well enough to sell.
Other thoughts, FPR faulty, not sure how to check without buying a tester, and finding a way to test it (there is a unique Hyundai adapter on this car.
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No comment..........
Strange as no other filter will work apart the original 1 fitted .
Yeah, we're wondering if some bodge was put on it to make it run well enough to sell.
Other thoughts, FPR faulty, not sure how to check without buying a tester, and finding a way to test it (there is a unique Hyundai adapter on this car.
So.
blocked fuel filter + faulty (or bodged) FPR = slightly high fuel pressure at idle & low pressure at full throttle.
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What about refitting new fuel filter but dont connect the outlet side,then see if there is fuel coming out when pump primes.
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No comment..........
Strange as no other filter will work apart the original 1 fitted .
Yeah, we're wondering if some bodge was put on it to make it run well enough to sell.
Other thoughts, FPR faulty, not sure how to check without buying a tester, and finding a way to test it (there is a unique Hyundai adapter on this car.
So.
blocked fuel filter + faulty (or bodged) FPR = slightly high fuel pressure at idle & low pressure at full throttle.
Its very rich at idle, and quite rich at higher revs. Hence FPR being considered.
Blocked filter? The 3 replacements have all prevented the car starting... ...though obviously I'm suspicious of something around the filter if only the original one works...
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What about refitting new fuel filter but dont connect the outlet side,then see if there is fuel coming out when pump primes.
I'm sure when he tried the first replacement filter, he confirmed he had a good fuel flow to the injector rail.
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No comment..........
Strange as no other filter will work apart the original 1 fitted .
Yeah, we're wondering if some bodge was put on it to make it run well enough to sell.
Other thoughts, FPR faulty, not sure how to check without buying a tester, and finding a way to test it (there is a unique Hyundai adapter on this car.
So.
blocked fuel filter + faulty (or bodged) FPR = slightly high fuel pressure at idle & low pressure at full throttle.
Its very rich at idle, and quite rich at higher revs. Hence FPR being considered.
Blocked filter? The 3 replacements have all prevented the car starting... ...though obviously I'm suspicious of something around the filter if only the original one works...
Sorry, didn't explain myself.
Try "partially blocked filter" + bodged FPR that doesn't limit the fuel pressure.
At idle enough fuel gets through for a rich idle.
At full throttle there isn't enough fuel (due to partially blocked filter)
Is the return to the tank OK? (has it been crushed or has someone put a restriction in the pipe perhaps?)
A new filter (with very little resistance) resulting in far too much pressure at the fuel rail.
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Understood, I'll get him to check :y. He was going to check the return anyway for restrictions.
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Hyundai, sell for scrap!
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Er, have I missed what car?
Hyundai, but not sure that makes a difference ;D
if it has 4 wheels , sucks air and fuel and pumps out burned exhaust gas.. it doesnt really!
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What model ?
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Er, have I missed what car?
Hyundai, but not sure that makes a difference ;D
if it has 4 wheels , sucks air and fuel and pumps out burned exhaust gas.. it doesnt really!
Ooh no. Can't post up without car/engine details. Ooh no. ::)
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Er, have I missed what car?
Hyundai, but not sure that makes a difference ;D
if it has 4 wheels , sucks air and fuel and pumps out burned exhaust gas.. it doesnt really!
Ooh no. Can't post up without car/engine details. Ooh no. ::)
it says rough running fuel trims all over the place.. so no proper combustion.. not a rocket science really ;D
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If it helps, its a Hyundai Santa Fe 2.4 (I think)
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If it helps, its a Hyundai Santa Fe 2.4 (I think)
Ah, so TB is evasive because TB doesn't know. ;D
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If it helps, its a Hyundai Santa Fe 2.4 (I think)
Ah, so TB is evasive because TB doesn't know. ;D
I'm pretty certain. Well reasonably ::)
It was more as the car wasn't relevant, as virtually all petrol injection systems are identical in operation.
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If it helps, its a Hyundai Santa Fe 2.4 (I think)
Ah, so TB is evasive because TB doesn't know. ;D
I'm pretty certain. Well reasonably ::)
It was more as the car wasn't relevant, as virtually all petrol injection systems are identical in operation.
Yes, but if that was the case there wouldn't be a problem by the sound of it. Seems there's something specific to this model, what ever that may be. ;D
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If it helps, its a Hyundai Santa Fe 2.4 (I think)
Mr Imber might be on the money :-X
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If it helps, its a Hyundai Santa Fe 2.4 (I think)
Ah, so TB is evasive because TB doesn't know. ;D
I'm pretty certain. Well reasonably ::)
It was more as the car wasn't relevant, as virtually all petrol injection systems are identical in operation.
Yes, but if that was the case there wouldn't be a problem by the sound of it. Seems there's something specific to this model, what ever that may be. ;D
Eh?
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If it helps, its a Hyundai Santa Fe 2.4 (I think)
Mr Imber might be on the money :-X
Whilst not my first choice of transport, its ideal for his needs... ...or would be if it bloody worked ;D
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If it helps, its a Hyundai Santa Fe 2.4 (I think)
Ah, so TB is evasive because TB doesn't know. ;D
I'm pretty certain. Well reasonably ::)
It was more as the car wasn't relevant, as virtually all petrol injection systems are identical in operation.
Yes, but if that was the case there wouldn't be a problem by the sound of it. Seems there's something specific to this model, what ever that may be. ;D
Eh?
Ah the standard "I've been rumbled" response. ;D
If it was a standard run of the mill engine, the parameters you've checked would mean all was well on a normal engine. There for, it's not a "normal" engine. There for the model and engine details might help. Just saying. Like. ;)
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http://pages.suddenlink.net/daydreamer/Coupe%20TSBs/Fuel%20System/10-FL-009%202.0L%20AND%202.4L%20THETA%20ENGINE%20ETC%20THROTTLE%20BODY%20CLEANING.pdf
worth a try,coolant temperature sensors can also cause issues not unlike what you describe
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I'd say check the fuel pressure if possible. Sometimes there's a schrader valve on the fuel rail.
Also, disconnect the return line from the rail and see how much fuel is flowing. Should be coming out at a decent rate at idle.
Is there a vacuum reference connection to the FPR? Might be worth checking if this is OK - not blocked or split.
The fuel filter issue is odd, though. :-\
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On the fuel filter front.. it's not something daft like a filter with built in one-way valve and he's been fitting them backward, has he? Just a thought.
I'd start with the obvious, too - fuel pressure and the TPS since you know it's not reading right. Is it possible to adjust the TPS on that car?
if the ECU thinks the car is really rich and needs to pull a ton of fuel, how old are the O2 sensor(s)?
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if the ECU thinks the car is really rich and needs to pull a ton of fuel
Ecu coolant temp sensor failure could also do that... a freely flowing pattern filter might allow too much fuel through, flooding it, whereas the original one full of crap and with a finer filter might slow the flow just enough to prevent flooding yet not allow enough flow at higher rpm :-\
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Reply from Bro, who read this thread yesterday...
I've not look yet. It is returning fuel. I connected a short length of pipe and container to the fuel rail outlet and it filled a 200ml (approx.) container in approx. 5 sec.
Turned the engine of just in time before it over flowed.
Another thought is could the purge valve be stuck open???? Looked inside the throttle body and the chamber appears to be wet?
Would burning oil cause long fuel trims and high emissions. Sometimes when I remove the EGR valve (especially as it is blanked off at present) a small amount of oil runs out of the inlet manifold.
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Ah the standard "I've been rumbled" response. ;D
If it was a standard run of the mill engine, the parameters you've checked would mean all was well on a normal engine. There for, it's not a "normal" engine. There for the model and engine details might help. Just saying. Like. ;)
What have you been smoking, I want need some ;D
LTFTs at anything other than 0% is NOT normal on ANY petrol injected car (with closed loop capability). You know that. So still in realms of standard petrol diagnosis.
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http://pages.suddenlink.net/daydreamer/Coupe%20TSBs/Fuel%20System/10-FL-009%202.0L%20AND%202.4L%20THETA%20ENGINE%20ETC%20THROTTLE%20BODY%20CLEANING.pdf
worth a try,coolant temperature sensors can also cause issues not unlike what you describe
Thanks, I'll get him to check. I know he's cleaned the idle valve, not sure if a different item on his engine, or if he's done your procedure :)
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Right, so he still doesn't know what car it is. ::)
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Right, so he still doesn't know what car it is. ::)
Reply #18 ???
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Further update from Bro
It's a Hyundai santa fe 2.4ltr petrol 2002
The fuel filter is an in tank type. The fuel pump sits inside the filter and can only fit one way. When it arrived I thought it was a star wars toy.
There is only one ECT that does both dash and ECU. As I get a reading on the dash temp gauge and approx. correct reading on code reader I think it's ok.
FPR vacuum connection and pipe look ok. (doesn't mean it's not faulty)
new O2 sensors fitted.
Some good news I swapped over the fuel return and 2nd tank connections and the LTFT is much improved whilst driving, still in the minus range but sometimes goes back to 0% and the car fells more lively. Unfortunately at idle the LTFT goes back to -12.5% and if the STFT is a high minus the O2 sensors just reads rich. If you lightly rev it and get the STFT down the O2 sensors start switching again.
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If it helps, its a Hyundai Santa Fe 2.4 (I think)
Ah, so TB is evasive because TB doesn't know. ;D
I'm pretty certain. Well reasonably ::)
It was more as the car wasn't relevant, as virtually all petrol injection systems are identical in operation.
Ar you sure this time? Absolutely certain?
No idea about these, sorry. ;D
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So its rich, yes? (Being serious for a minute)
So not fuel restriction.
Temp sensor correct? As Al said.
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And...
When I block the FPR vacuum hose there's no change in fuel trims or O2 switching. I'd expect the fuel to go rich(er)
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So its rich, yes? (Being serious for a minute)
So not fuel restriction.
Temp sensor correct? As Al said.
As above, live data shows ECU coolant temp reads approx. dash temp.
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And...
When I block the FPR vacuum hose there's no change in fuel trims or O2 switching. I'd expect the fuel to go rich(er)
If the FPR is knackered, could it be supplying fuel at way too high a pressure thus causing mahoosive overfuelling ?? which the fuel trims are desperately trying to cut back, hence the high minus values ??
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So, something's causing it to go pig rich at idle. Guessing if the lambda sensors were lying, by the time the fuel trim has got to -12% it's be idling pretty rough.
Could be purge valve stuck open, I suppose, but wouldn't have thought it would draw that much vapour in. Easily eliminated by clamping the hose to the carbon canister.
Leaking fuel injector, perhaps? Is it worth jury rigging the fuel pump to run and looking down the manifold to see if one of them is dribbling?
After a bit of idling, cut the engine and inspect each spark plug? Are they showing signs of running rich? Are they all looking the same or is one especially sooty / wet?
How does it run if you disconnect the lambda(s)? Guessing it'll revert to 0% trim in some kind of limp-home strategy. If it really was rich, it'll idle grumpy. Ditto if disconnecting the MAF, I suppose.
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So, something's causing it to go pig rich at idle. Guessing if the lambda sensors were lying, by the time the fuel trim has got to -12% it's be idling pretty rough.
Could be purge valve stuck open, I suppose, but wouldn't have thought it would draw that much vapour in. Easily eliminated by clamping the hose to the carbon canister.
Leaking fuel injector, perhaps? Is it worth jury rigging the fuel pump to run and looking down the manifold to see if one of them is dribbling?
After a bit of idling, cut the engine and inspect each spark plug? Are they showing signs of running rich? Are they all looking the same or is one especially sooty / wet?
How does it run if you disconnect the lambda(s)? Guessing it'll revert to 0% trim in some kind of limp-home strategy. If it really was rich, it'll idle grumpy. Ditto if disconnecting the MAF, I suppose.
LTFTs on this ECU max out at -12 or +12, so impossible to say how far beyond this its actually going (to be absolutely accurate, for Mr Pedantic Gixer Bloke, its 12.5%, which is what bro is seeing.