When I leave my driveway in the morning on cold days I try to accelerate and I get this sucking sound like there's a vacuum leak (the vehicle doesn't want to move). I let off of the pedal and it goes away. When I accelerate hard the vehicle doesn't want to go. I push it harder it struggles and finally the sound goes away and the vehicle will accelerate normally. In the warm weather there is no problem with the way it runs. There's a noticeable lose of gas mileage. On real cold days you can hear the sound cycling. It seems like theres a tremendous amount of back pressure on the engine.
Any Info on what to look for would be greatly appreciated!

 

There are some ways to check for a converter that is becoming restricted and that is using a vacuum gauge. Unless you have one or care to rent one something you can try, when you first start the engine and the engine is cold place your hand near the exhaust tail pipe and see what you feel. If the exhaust is restricted you will feel very little pressure coming out of the pipe. Then when it warms up check the pressure out of the pipe again, but be careful now it could be hot. If there is a big difference in the pressures there could be a restriction in the exhaust and it doesn't necessarily have to be the converter. Sometimes the pipes can collapse internally and produce a restriction that comes and goes. If you notice no change then to confirm the suspicion you need to connect a vacuum gauge to the intake and watch the reading at idle and then when the RPM is raised to about 2000 and held there . If the vacuum reading drops lower and lower there is the good possibility of a restricted exhaust .
If there is an exhaust leak that is affecting the oxygen sensor fuel to the engine could be affected.

 

Thanks Hanky Ill check the exhaust first and see what happens. I'll make an attempt to search for a vacuum leak at the intake, Ill recruit some help for this. I'll also get underneath it to look for an obvious exhaust leak.
I had a quick thought.
Do you think the exhaust back pressure valve could have anything to do with this. since the EBPV simply helps to warm the engine up, and this happens in the cold weather only.
What controls the EBPV? Please excuse my ignorance to all of this,this is a huge learning curve for me.
I appreciate your efforts.

 

I should have known better than to assume you had a gas fired engine. Your following questions pertained to a diesel engine. Soooooo, what engine does your vehicle have in it gas or diesel?

 

Hanky thats my ignorance for expecting everyone to read my mind, my wife says thats awfully hard to do.
It is a 7.3 diesel.
If you have any info on my issue I'd love to hear it.
Thanks

 

You never know how people will take things in a conversation, but at least your wife acknowledges you have a mind. Mine says I've lost my mind and she's just being kind !

 

Instead of shooting from the hip and throwing out various possibilities , is there a place close by that can check the computer in your vehicle for any stored codes. A faulty MAP sensor can provide false info to the computer regarding turbo boost, but changing parts without knowing if they are defective is not the correct way to go. If the back pressure sensor is not sending the correct info to the computer , the computer will substitute values to compensate , so it should not be that noticeable.
Any codes received should provide some direction.
Sometimes a loose hose clamp in the intake system will allow turbo boost to leak out through the leak instead of going directly to the engine.

 

Sounds like we're in the same boat with the wife situation.
I'll see if I can get someone to check for the codes. It might take awhile but it does make sense. If the weather wasn't so cold now I would take the inner cowling off and check for bad intake hoses.
Ill look into a new MAP sensor if the price is reasonable it would be worth it to me.
Thanks again. Ill let you know what comes up.