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Engine, Exhaust, Transmission and DifferentialPost questions here that have to do with the engine, cooling system, air intake, exhaust, Transmission and Differential
Have you removed the throttle body. The O ring is a known problem not lining up an staying in place, when reinstalling. Or it may have just ruptured. You say you can hear it sucking air ..that is a problem.. we all use different methods when checking for vacuum leaks. I use either WD40 or carb cleaner. Spray ,w/ engine running, where you feel the air is leaking or a open vacuum is. The idle will either up or down depending or its routing...sounds like this is driving you crazy...lol
I have not removed the throttle body yet. It is making a suction noise by it, like it is pulling in air when i hit the gas. I will get some carb cleaner tomorrow and spray around the throttle body . Which O-ring are you referring to on the throttle body that could be ruptured. I will check that as well. Thanks
Its under the MAF sensor where it connects to the top of the motor. Also is the gasket for the air filter housing in place an properly seating , when your installing it?
Make sure you use a Bosch crank sensor, I bought a napa brand one because that’s all they had in stock that was actually more money then a Bosch and got probably six cranks out of it before it went bad. Also sounds stupid but make sure that plug is in all the way, it’s in a tight spot sometimes you think you tighten them all the way but it might not be.
You have a o ring on one side of the throttle body that goes between the throttle body and the intake and then there’s a thick o ring that sits on the MAF sensor that goes between the MAF and the throttle body. I used soap and water to find my vacuum leak. Your not located around New Jersey are you.
Ok So I am still working on this mess and did get somewhere today. Car still running rough no power. I had the car running and pulled the harness to ecu off of each coil to see if the engine stumbled. Some caused it to stumble others did not making me believe wire harness issues. I traced all the wires back to the ecu, all wires looked good. I started to wiggle the wires in the ecu and car almost shut off, then wiggled again and was running slightly better. I turned car off, unhooked some of the wire harness plugs in ecu and noticed some pins lower than others. I pulled the clips that locked the wires into place off giving me a 1/32" more area of connection to the pins, installed the loose square blocks over the pins and woosh, no more cylinder misfires, no more knocking, no cylinder misfire codes so made progress. I attached pictures of the clips so people can see what im talking about.
I still have one remaining issue. When i hit the gas pedal the car stumbles and then slowly gets up to speed. The car will rev good when some gas is already applied, it wont rev directly from idle, it stumbles. I checked any air leaks with carb cleaner, no vacuum leaks. Its pulling air hard through the maf sensor when i first hit the gas. Its not an air leak just pulling air hard and causing the car to stumble. I am thinking this could be a low gas pressure issue (bad pump) or possibly a dirty fuel filter? Do i check the fuel rail pressure next? Is the pressure supposed to be constant when i hit the gas? I will pick up a pressure gauge tomorrow.
Ok so I still have no check engine codes since the ecu connection. I am still getting a stumble at throttle. I checked the fuel pressure at the rail and am getting 55 to 52 psi constant when idle and at open throttle and rev. So it seems fuel pressure is not an issue. I removed the throttle body, cleaned it and lubricated it, also put a new gasket and used gasket sealant on the o-ring and 2 maf sensor seals. Still same issue. I am beginning to think i have a bad MAF sensor possibly, unless anyone else has any other ideas?
Ok so I still have no check engine codes since the ecu connection. I am still getting a stumble at throttle. I checked the fuel pressure at the rail and am getting 55 to 52 psi constant when idle and at open throttle and rev. So it seems fuel pressure is not an issue. I removed the throttle body, cleaned it and lubricated it, also put a new gasket and used gasket sealant on the o-ring and 2 maf sensor seals. Still same issue. I am beginning to think i have a bad MAF sensor possibly, unless anyone else has any other ideas?
I would not recommend the use of a gasket cement on an O-ring, especially one in a delicate spot that this one is. The O-ring should be allowed to fit into the groove freely so that it can seat evenly all around, sealant could possibly prevent this. I hope the O-ring was new, if not you could still have a problem.
Ok So I just purchased a new MAF sensor and CamShaft Sensor and installed, Still stumbles, no power, throttle weak and rough idle. Other parts i just replaced and rechecked multiple times. New Wires, New spark plugs, new coil packs, new injectors, checked fuel pressure and is constant 52 PSI at idle and wide open throttle, new EGR valve, new air filters, new oil change and filter, new Bosch oxygen sensors, New seal on air intake, removed throttle body cleaned, oiled and replaced with new gasket. I removed the entire exhaust no plugs in exhaust and reinstalled. Any other suggestions? I am uploading a youtube video so you can hear the car. I will load the link soon. I am running out of ideas here.
Dumb question , but 12 wires ,1intake 1 exhaust on each cylinder , could you have 1 cylinder crossed. Or as Needswings suggested , valve seal or not seating , but you would think ,that would throw a code of some kind. Or smoke a little...
Dumb question , but 12 wires ,1intake 1 exhaust on each cylinder , could you have 1 cylinder crossed. Or as Needswings suggested , valve seal or not seating , but you would think ,that would throw a code of some kind. Or smoke a little...
I check the cover multiple times, its tight and sealed, seal is ok too.
I sprayed brake cleaner by the intake and did not find any leaks.
I did not check the Catch can for an air leak. I will look at that tomorrow.
TB hose is tight against the intake and the MAF sensor
The valve seal leak, where would that be located. All my injectors are new and have new seals. Where would I find the valve seal? Do I pull a valve cover, and how do I determine a seal leak on which valve? Thanks Guys. Im not going to let this one beat me. I will order a new seal for the air intake too. I just replaced the seal on the throttle body.
Re: Cylinder Misfire Help
