2.4 running rough

Roadrunner said:
It does alot more then just that...since he has no code and the problems he has can be caused by so many different reasons, he might aswell check it just to be safe..
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Can you elaborate more on what the vss controls. Im alwys looking to learn more?
 
Zimgxp said:
Can you elaborate more on what the vss controls. Im alwys looking to learn more?
Click to expand...

it also helps the egr figure how much to open,shift points and cruse control..though it's main objective is to covert voltage to mph..it still has it's hands in the egr system..so if the vss is not working 100% it could be telling the egr to open more at idel and cause the car to run ruff
 
yes! but the ecm needs to gather info from all the sensors to come up with what it needs to do in order to make sure the opperation of the car is at optimal/efficient levels..
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That's why throu the years you would have 1 o2 sensor, and now cars can have up to 4..the more readings the ecm gets the best choice it can make..they even have cars with 32 bit processor to keep up with the new tech and all the extra sensors they added to cars..
 
should I replace the VSS? It idles rough and runs rough all around until it gets to the magic rpm number. you can hear it chug at idle. Once on the highway, the cruise works fine and it seems to run ok at highway speeds. It is the worst around town trying to take off from stop signs.
 
I would not replace it, but check it..so the pcm did not work for you? tell me again whats wrong and what you have done so far.
 
This is what I have tried:

Removed and cleaned injectors installed with new o rings
new plugs
2 new coil packs
New (used) white plastic Distributor thing
New ignition module
new gas cap
new map sensor
new tps sensor
new cam position sensor
new air filter
new fuel filter
cleaned throttle body (including Idle control valve)
put heet in gas tank
tested compression (180psi on all 4)
Removed O2 Sensors and visually inspected, looked fine)
New Crankshaft Position Sensor
Removed EGR Valve and comfirmed that it is closed at idle. Seems to be working correctly
searched for vacuum leaks with carb cleaner trick..... no luck
Got a new PCM from the junkyard, but dealer wants $150 to "flash" it

I think that is everything. Maybe I will try to test the speed sensor next. Thanks again.
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Try doing a fuel pressure test aswell..but also since you have brand new plugs, pull them out 1 at a time and remember which piston you pulled them from and write down what they look/smell like..
 
I cannot test the fuel pressure since there is no schrader valve and none of the fittings fit anywhere in the system. One of the fitting might fit between the filter and the threaded hose, but I cut that part off so there is really no way that I know how to test it with the kit from Autozone.

I do need to do a plug check. I might drop it off at a shop tomorrow. I am to the point where I will pay them $100 to tell me what the problem is:) I will let you know what I or they find. Thanks again.
 
Yepper!..just like I told you from the get go...the p0300 can be a pain in the butt to figure out and make you go nuts..let us know the issue..I really want to know what it is.
 
Well for $70 they found out the timing chain tentioner is bad and the timing chian is jumping teeth. They quoted me $900 to fix. I might end up selling it to the gargage where I bought it for the same price I paid for it and get something else. I don't think I want to dive into that project. Thanks for all the help everyone
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Really!?..damn I never would have thought, because your car still ran..well I hope all goes well for you..
 
how hard would it be to replace the timing chain and tentioner?
 
not hard at all, just timely...the best thing you could do it get a haynes or chilton which is no more then 30 bucks
 
How did they verify that it was the timing chain and tensioner? I have a 98 se with a 2.4 with almost the exact same problem except it idles bad. Start it up idles ok for a few seconds then rpms on dash bounce between 800 down to 600 shakes bad does it in park any gear but once running on the road its good above 1000rpm.

All I get is p0300 new plugs coils housing icm fuel pressure i can measure because i modded the fuel rail to accept a pressure guage its around 40 at idle. Last thing I replaced was the injectors made it crank alot easier thats about all though. 100 positive no vac leaks
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