Hyundai only goes up to 50km

GMC guy

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Hello all. I have a 1996 Hyundai accent 1.5 L 5 spd standard 170, 554 that goes up to 50 km per hour then tries to cut out. (Like it runs out of fuel) Even if i hold the gas pedal to the floor in neutral it does not have hi rpms. I scanned it and it gets codes po300 eva random misfire, po 103 maf circuit high input and fuel syst 1 closed loop calculated load 38.4 % .

So far, i understand that I need plugs, plug wires, maybe coil packs, but do not understand the fuel system closed loop...does this mean I need a new fuel pump as well? I suspect the fuel pump. I changed the fuel filter. Any help would be greatly appreciated.
 

schraube

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You should deal with the MASS-AIRFLOW sensor (MAF) first .This device registers the amount of air being sucked into the engine and the computer then calculates the amount of gas to be injected. Your Maf isn´t working and so the computer can´t provide the correct fuel /air ratio and the engine runs poor or doesn't run at all. Check for loose connections, broken wires before buying a new one. You might try to clean the MAF with breakcleaner, be careful not to damage it, they are sensitive,
Closed loop means the oxygen sensor provides information to the computer (Cm), so the Cm has More info to control fuel delivery, emissions etc. Closed lop is NO problem,it is desired in stead of open loop.
First things first, start with your MAF-sensor and keep us informed. Grettimgs Jürgen
 

dave_X86

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I never hurts to think that a filter is a good thing but they can suceed in failing. Replace the fuel filter if the first two suggestions do not work. Take care
 

GMC guy

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Hey all. Thank you for your replies. I have been busy but am back to the Hyundai problem. I wouls suspect the timing belt but that is more of a gradual acceleration thing. THis problem is sort of like the fuel supply has been shut off or somethihng. I sprayed the sensors inside and out and replaced one gasket. Still a problem. The car starts easy and drives, but chokes out or runs out at 5o km. Once I let the gas pedal up a bit it pulls again. I am wondering if I should just go ahead and replace the fuel pump. Is that advisable?
 

Jim Fairbanks

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Have you changed the fuel filter like Dave suggested?.On the firewall - driver side, beside the brake booster assembly...also check the fuel pressure....Regulator Pressure 300kpa (3.06 kg/cm2, 43.5 psi) ......Jim

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GMC guy

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I just checked. The filter is not there. There is a black box thing that is attached to the air intake just after the filter. I was told that the fuel filter was changed already.But maybe this is a 1994 with a 1.5 It is owned by my sister.
 

GMC guy

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Sorry Everyone. The car is a 2000 Hyundai . It does not have a fuel filter. I raised the car and followed the gas lines and there is no filter on this car. I thought my troubles were over...! ???
 

Jim Fairbanks

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Yes...it has one......Jim..........

On top of the fuel tank beside the fuel pump. Accessible by removing the rear seat and detaching the inspection panel of the fuel pump.








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GMC guy

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Thank you Jim. I found the fuel filter. Such a strange place to put a filter. But I also found that the car is running on two cylinders. I pulled the plug wires one by one. No spark to the one and four cylinders. I ordered coil packs and will replace all four. I hope this is the answer.
 

GMC guy

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Hello. I changed the coils and the engine is running on all four cylinders. But, it still revvs to close to 2500 rpms and just stays at that level. There is a occasional faster revv but it only lasts less than a second. I can put the pedal to the floor and it revvs to 2500. I had one guy suggest the pulse sensor on the tranny. Though i was unable to get that MAF sensor module off as it takes a special tool. Help! |??
 

GMC guy

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I also need to pull the plugs and change them. Maybe it will run even better after that.
 

GMC guy

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Hello All. I put the new maf sensor and still have the problem. I disconnected the oxygen sensor and I got very high revvs but still had tough time to get it there. I went under the hood and the maifold and whatever that big thing is inder the manifold were red hot. I dropped the exhaust pipe half way down to the back and still no change. Is that a catalytic converter under the manifold? It seems I may have to disconnect all those manifold bolts and change that whole piece, as it looks like it is welded to the manifold. Am I going in the right direction?
 
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