Engine/Transmission (1994 - 1998) looking at buying a 98 what do you think?

[edgeman]

i m looking at a 98 12 valve. it has some upgrades but there is something that i am not sure about. i was looking under the hood and i noticed that the line hooded up under the turbo waste gate actuator is not not hooked to the intercooler turbo housing. i noticed on the back side of the injector pump where the fuel plate housing is at there is a vacume? (plastic tube) line that runs from the fuel plate housing to intake manifold. there is a T in that vacume line which runs over to the turbo waste gate actuator. Now i am wondering why they would have done that. any thoughts.



Ethan

 

[kenny61]

Thats the way my 96 is it t's off between afc and wastegate

 

[Bob V]

Yes, that is the way it came from the factory. And it is not vacuum, it is boost

 

[edgeman]

oh ok im not to good with all the vacuum and boost thing i get confused easly. thank you for the help.

 

[kenny61]

theres no vacum on the diesel other than from the pump to the brake booster and hvac controls

 

[fest3er]

i m looking at a 98 12 valve. it has some upgrades but there is something that i am not sure about. i was looking under the hood and i noticed that the line hooded up under the turbo waste gate actuator is not not hooked to the intercooler turbo housing. i noticed on the back side of the injector pump where the fuel plate housing is at there is a vacume? (plastic tube) line that runs from the fuel plate housing to intake manifold. there is a T in that vacume line which runs over to the turbo waste gate actuator. Now i am wondering why they would have done that. any thoughts.



Ethan

Answers:



As other said, it's boost, not vacuum. As to why, the manifold-to-AFC line limits fueling in proportion to boost (to a certain degree). The manifold-to-turbo line opens the wastegate when boost exceeds some pressure (stock is around 18PSI, I think).

 

[edgeman]

well my son (ethan) and i took this truck for a drive today, all i can say is WOW !!! i dont know what someone did but this truck is strong!! im getting it from a used auto lot here in the upper peninsula of michigan. the truck came from texas. how can i tell if the gov. springs have been changed? it runs up the rpms alot more than my 96, or ethans 95.

 

[edgeman]

theres no vacum on the diesel other than from the pump to the brake booster and hvac controls... ... . Kenny61 there is vaccum in a diesel, but it is uncontrolable vaccum unlike cars you can't use it but for like the powersteering, hence why you have a vaccum pump on the engine its self. Thank you!

 

[Vaughn MacKenzie]

theres no vacum on the diesel other than from the pump to the brake booster and hvac controls... ... . Kenny61 there is vaccum in a diesel, but it is uncontrolable vaccum unlike cars you can't use it but for like the powersteering, hence why you have a vaccum pump on the engine its self. Thank you!