• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Code 78

Sinners Saint

Sinners Saint

New Member
Messages
82
Reaction score
4
Location
Houston, Texas
Threw a code 78 today while on the beltway. Looked it up and its a turbo boost solenoid failure, ok, but I have a manual wastegate controller on my turbo. An I pushing too much boost? should I dial it back a little? I think the most I've seem it hit was 13, but I have'nt put my foot in it as hard as I did today and I wasn't watching my boost when I got the SES light.
Opinions?
 
I've been running it this way for about 3 weeks and thats the first time it throug a code. Guess cause it was at that high for a longer period of time. It regulary sees around ten when I'm driving the freeway because I throttle up quite often when dring in traffic (inpatient driver). I'm gonna keep an eye on it next time I'm running it ard to see what it goes up to. I have'nt done an exhaus yet, one of the next things I have planned. I want to do the 3to4 ssd down pipe and go 4 inch back to a set of 5 inch stacks. I also want to put a higher flowing air intake on it, like the ones Leroy sells. Thats if I get to it all before I go back to work full time (on disability right now). Then I can afford to sell it and go buy a newer truck with a duramax. Still gonna be awhile though so we'll see.
 
Theres nothing wrong. you just have more boost than what PCM was targeting. And PCM wasnt able to control it down because you removed vacuum actuator. It takes a few seconds at the high or low boost condition before the PCM will throw the code though. You can either get a custom chip so it doesnt code and defuel, or put on a boost fooler potentiometer.
 
I had the exact same scenario when I made my TM. I dialed the boost down a little and no more codes. Max 11psi fully loaded up a hard hill, usually 10psi at normal rush push.

You running hard on the beltway 8 or up on the Sam Houston tollway? (Lived near Jersey village for 12 years, FM1960/Jones rd. Made it from Incercon down to Hobby in 18 minutes one time, in my '67. AH, memories.
 
You must log in or register to reply here.
Back
Top