1997 Ford Explorer 6 cyl. P0300 code shown. Code went away on it's own. Within 50 miles of the P0300 code disappearing, the codes P0171 and P0174 were thrown. Mechanic checked vacuum lines and no leaks. He changed the MAF and no change. Truck is stalling immediately upon a cold start unless given constant gas. Once warmed up, runs okay other than a rough idle. There are no codes thrown for the O2 sensors. Replaced Fuel pump and filter 1,700 miles ago. Throttle body was cleaned at the same time fuel pump replaced. What do I check or replace next?
I've fixed many of these on a Ford and they are nearly ALWAYS a vacuum leak. Have it smoke tested if you have to but you are going to find a rather large leak, most likely on a rubber elbow connector.
October, 26, 2012 AT 11:30 PM
It was smoke tested. There are no vacuum leaks.
October, 26, 2012 AT 11:36 PM
Not sure why my original post says pending member, but the original question post and the response are both me. I thought there would be a leak at the intake manifold that we couldn't visually see or an exhaust leak somewhere. That is why I had him smoke check the vacuum system. No leaks anywhere. That is why I am stumped. I do not know what else it could be.
October, 27, 2012 AT 1:16 AM
I think I would want to check it again. I've just seen it too many times. Also look for any air leaks in the intake snorkel between the MAF and the throttle body.
October, 27, 2012 AT 3:20 PM
I will have it checked again by a different place. I think I may have found what it is. I am going to replace it later today to see. I forget what it is called, but it is a y kinda shaped elbow that is $384 dollars for just the rubber elbow thing through Ford. You can't get it anywhere else except a junk yard. I managed to get 2 for $20 dollars from a junk yard when I noticed it was ripped right after I got my truck. If it doesn't fix the issue, could it possibly have anything to do with the injectors? I do not want to add anything to the system for fear of what happened to my last car. I was told Seafoam was a good cleaner and ended up with a blown engine from it.
October, 27, 2012 AT 3:24 PM
If that is a vacuum elbow, it's exactly what I was talking about. I don't understand the price though. Those vacuum assemblies are usually much cheaper.
October, 27, 2012 AT 3:37 PM
It goes to 3 different lines, one of which is a capped off pipe that runs along side the motor, one of the other lines goes to the air cleaner box and the other I can't remember where it goes maybe the intake itself. Give me a minute, I will go pull it off and run the part number and tell you exactly what it is. It is an air intake something or another.
October, 27, 2012 AT 4:07 PM
It is an Air Inlet hose. The price is because nobody but Ford makes them.
October, 27, 2012 AT 4:11 PM
I do not think that is the issue now. It isn't ripped all the way through. It has a minor crack on the outside, but doesn't go all the way through. It is also on the end so the line that goes to the air box sits inside and covers where it will be ripped in the future anyway. Not sure what is happening now.
October, 28, 2012 AT 2:39 PM
I looked at everything. Still going to have it smoke tested again, but I have a crazy question. My Explorer is a Florida truck. Has always been in the warm climate up until 2 months ago when we moved to New Hampshire. Since we have been here and I have had to park on an incline, this issue has been happening. I have parked on a flat street a few times and didn't have this issue when I started my truck. It seems to be happening ONLY on cold starts that I am parked on an incline. This morning, I started it on the incline and then backed it up onto flat surface. While on the incline it ran like it normally does at start up, rough and have to give it gas or it will stall. The second I got on the flat surface, the idle evened out and ran perfect. I have tried this a few times, and each time got the same results. Could the fact that I park uphill have something to do with anything?