highway speed studdering...

[N1265]

Hi guys,

once in a while my 96 ex will "stumble" It only happens at highway speeds, is brief, and appers to only happen with the cruse control on. I am not sure if it is a miss or a fuel issue. The car has 255k miles on it.

the coil, wires and fuel pump have about 140k on them.

when a pump goes does it give any warning, or just quits working all at once ?

 

[N1265]

Hi guys,

I still have this problem, The car now has 265k miles on it.

It is NOT limited to the cruise control, the condition comes and goes as it pleases but if you stomp on it, it will get up and accelerate normal.


I have cleaned and gaped the plugs ( witch looked normal )

It seems to get worse below a 1/2 tank of gas.
( but this could be my imagination ) what is the deal with 10% ethenol, does using this gas create any problems ?

I checked the TPS and it tested good, But I am wondering if they will "come and go " Or will they just go out like a fuel pump ?


I read another post where a guy disconnected his MAS and threw the truck into a " bypass mode ". Is there any I need to know about running in this mode ? I really don't care about the gas millage at this point.

Also, FYI, years ago the tube that runs to the EGR and exhaust manifold rusted threw, I plugged the exhaust leak and just kept going. It ran fine like this for the longest time and I doubt it would be the issue, but bring it up just in case.

 

[N1265]

here are the codes :

1131
1151
0301
0302
0303
0171
0401

 

[pickupman6]

Change your plug wires

 

[pickupman6]

Your stuck with the p0401 unless u fix your egr pipe, 0171 could be a number of things, but since its just on one side it could be lower intake gaskets are leaking I suppose upper intake gaskets could cause this too, a faulty injector, which also could be a cause for the misfires, or it could be an o2 sensor giving a faulty reading. I'm battling that one too and I've replaced all that plus a lot more and its still there and no one can figure it out.

 

[N1265]

when a coil pack goes out, will it act like this ?

If I disconnect the MAF sensor, would it throw the truck in a "safe" mode and make the EGR and o2 sensor irrevelant ?

Just awful confused as to why it will run great and then out of nowhere start to run bad. the wires are a good posibility because it seem it is worse when it is rainning out, but I cant see any spark jumping around in the dark ...

 

[pickupman6]

Trust me its your wires , after time they build up resistance and cause the truck to misfire under load. Does it happen mostly when going up a hill(even a slight hill will cause it). You should pull your plugs too. Running lean can burn them up. I wish I could tell you why bank one only is running lean but I can't. Mine is too. You should still check the things I listed above and for good measure change your fuel filter. That got rid of the 171 one time for me the first year I had that problem. U could swap o2 sensor from one bank to the other and while you have them out clean them in some kerosene, over time they can get built up with carbon and give a lean code even though it the engine is running right. By that time its actually running rich cause the computer is dumping as much gas as it can on that side. That's why you need to pull yor plugs and see what they look like. If they are black your o2 sensor needs cleaning/replacin. Running rich will also cause your misfires you have. And since they're all on the same bank, pulling plugs and checking the color might not be a bad first step. Another thing you could try is spraying brake cleaner on your intake where the bolt on. Sorry for the long post. Good luck.