hello map sensor question

[GREG]

I am new to the diesel world I just bought a 96 f250 psd it is a good truck but it seems to have a part throttle bogg now my question is the map sensor reads about 15psi at idle and will run up about 33psi at wide open throttle put a manual gauge on the truck and at idle about 0psi i didnt try wide open I can unplug the map sensor and it read the same with a snap on scan tool any help would be thankful thanks

 

[DaveBen]

What are you trying to do? This doesn't sound correct. The map sensor reads absolute pressure, that is 14.5 psi at idle = 0. Under standard conditions.

Dave

 

[DaveBen]

I am sorry. By the way welcome to SDD.

Dave

 

[GREG]

I am sorry. By the way welcome to SDD.

Dave

Alright maybe you are the guy I need to talk to what I am trying to do is get the part throttle bogg out of the truck I undersood the map sensor by the scan tool to read the same as a manual gauge if I am wrong that maybe better but anther question is the obd2 connector wont power scan tool with out holding the button on

 

[whatabudro]

What Ben was saying is that atmospheric pressure is roughly 14.5 so you have to use 14.5 as your zero, then your readings make perfect sense. Follow?

And welcome to the site by the way.

 

[GREG]

What Ben was saying is that atmospheric pressure is roughly 14.5 so you have to use 14.5 as your zero, then your readings make perfect sense. Follow?

And welcome to the site by the way.

thank you well do you have any ideas on the bogg then

 

[DaveBen]

The bog is usually caused by turbo lag. It can be caused by other things, like a bad high pressure fuel pump to the injectors (injector pump). You really need to get a scanner on it to see what is going on.

 

[whatabudro]

It could be many things. Does it happen all the time, some of the time? Same spot in the pedal? It's fairly comon to have a pedal assembly go bad, but thats a guess at this point. We need more specifics like operating temp, miles on the truck, mods to the truck.

 

[GREG]

It could be many things. Does it happen all the time, some of the time? Same spot in the pedal? It's fairly comon to have a pedal assembly go bad, but thats a guess at this point. We need more specifics like operating temp, miles on the truck, mods to the truck.

Alright it happens all the time at any piont below 2000rpm I have a 30hp chip open exhuast cold air intake shimmed fpr truck can be rolling a few mph and nail it and fall on its face and then pick up and go

 

[roosterdiesel]

Have you changed the fuel filter?

Don't forget you have a huge 1.15 A/R exhaust housing that isn't going to spool all that quickly, if the turbo is in stock trim.