fried dmbc

[Hiitman]

i was wondering if this was possible. ive got a dejon dmbc. i had it mounted on the far left fan mount. heres the problem. i had it set at 18psi. after a couple weeks it jumped up to 22psi. ive got both screws turned completly out and it still wont go down. i took the dmbc off and im just running off the wastegate spring (10psi). i was thinking the problem could have also been the autometer gauge. im now running defi gauges but havnt hooked the dmbc because i want to get my fuel trims and a/f ratio set at a low psi. anyway. could too much heat fry a boost controller?

 

[TwoLiterLaser]

Unless the heat caused a spring to seize somehow, I do not know how heat can affect an mbc. You sure a vac line did not blow off somewhere?

 

[Hiitman]

fairly sure. running the wastegate to the turbo holds a steady 10 psi, which is the spring in the wastegate.

 

[jtmcinder]

MBCs have a bleeder on the output side, so even when set to full soft, they raise boost a little.

But not 8 psi.

If you have a MitiVac and a spare boost gauge, MBCs are easy to test. You are looking for repeatability. Anything that doesn't open at the same point ten times in a row is trash. Use the hoses from the car for the test, because that's the set-up you can about.

- Jtoby