I have a 01 windstar. About a month ago I had extremely rough idling with CEL on with codes p0171 and p0174. I found it to be the vacuum line connecting the gas regulator to the intake maniford was in half. I replaced it and instantly idling was fixed. I was unable to clear the codes ( I tried disconecting the battery after AutoZone claimed that they could not clear them with there scanner) so for about 3 weeks the car drove fine with the CEL still on.
A few days ago my wife complained about the car being very rough goign down the interstate as well as the car jumping foward when she was trying to park. This is not a little jump think about you going 2mph and all of a sudden the car jumped to 1500rpms. It really moves the car. It does it in fowards and in reverese.
I still had the same two codes, as well as I can hear a vacuum leak. When idling you can hear a vacuum leak and then the car revs, then anywhere between a few mins to a few seconds it will happen again.
I determined that the rough drvining on the hwy is due to missfing. I had a p0301 code (engine one misfire) I also had on several occasions the CEL to blink for about 5 mins. For reading forums I read that it is due to really bad misfiring cause fuel to dump into the catalilic converter.
I also heard a pinging noise when accel and could feel it in the gas peddal. I determined this to be misfing as well.
What I have done
I found a TSB regarding the 171 and 174 codes. It said to replace the 6 port seals as well as the isolator bolts. I also changed the spark plugs.
Since doing that poping noise when acel is gone and all the CEL codes are gone. However I still have the car jumping foward as well as rough driving. I seem to only have the rough drving between 1k to 3k rpms. Going above 3k rpms the roughness stops.
I still have rough idling. I can actaully still hear a vacuum leak. I hear the leak then the engine revs.
From where the sound of the vacuum leak is it is very possibly that it could be comming from the gasket for the two halves of the intake mannifold. I have not replaced it due to the TSB saying do not replace. And I am a bit confused as to if that was leaking as well why I do not have the 171 and 174 codes. I have heard if it is leaking from that seal that I can spay some carb clearing around it and it the idling gets worse then thats where is it leaking from.
I plan on checking the resistance for spark plug cable one and see if it is in a normal range.
I found another forum where someone was complaining about the car jumping forward with there foot on the brake (this is the only problem they had) the person responded saying to check the switches on the brake (he said there was two of them) and one of them is a trans dump valve which prevents the engine from loading up at lower rpm ie stopping at lights while in drive.
I am not sure where to go from here. I dont think the the switch on the brake is my issue do to them not having my other problems. I do know that I still have a vacuum leak, misfing cyclinders, car jumping foward, as well as poor idling.
Does anyone have any suggestions as to where I should go from here?
Also here is the TSB I found
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