hi every body im new to this site. i own an 82 280zx turbo and when i start it up and try to rev it up the car back fires and the turbo emergency relief valve pops open also and i was just wondering if anyone could give me some adivice on what could be wrong thanks

 

do you think the turbo could have too much carbon in it

 

Backfiring on these cars is pretty common. I doubt it's the turbo itself. A slack timing chain can cause backfiring. If the timing is off then you can get backfiring. A stuck or leaking valve can cause backfiring. A malfunctioning EGR can cause backfiring.

The turbo relief valve should not be opening while the engine is revving though. The spring could be worn and so its not holding pressure. You can shim the spring with washers to increase spring pressure and that will raise the pressure at which the relief valve opens. Of course if your boost level is soaring over stock then that would be another reason the relief valve is opening.

EDIT: IF the turbo had too much carbon in it then it would decrease boost if anything and therefore decrease the chances of the relief valve opening. The only way carbon could effect the relief valve is if there is enough to effectively block up the wastegate opening and allowing the turbo to over boost. Whats your boost pressure at when the valve opens?

 

im not sure of the boost but when it starts doing it is when the rpms are around 3500 and then all of a sudden i will hear the turbo valve opening and closing and making a loud poping noise and even when i feather the throttle it wont come out of it and i cant get the rpms to go over 3500

do you think i should take the turbo off to clean it anyways?

 

i know the boost isnt over stock though

 

Taking the turbo off is not small task. It's a pain in the *** and I would save that as a last resort (unless you wanted to take it off anyways). Check your sparkplugs first. Make sure they are in good shape. Also check out this link: http://home.flash.net/~joeao/greg/adjpopoff.html . That will tell you how to shim your emergency relief valve if its the problem. You do have a boost guage right? If so you need to check what boost pressure it's reading when this happens. If it's doing this prematurely at low boost then it's an issue with the relief valve. If you dont have a boost guage then you need to get one. It's dangerous to run around without a boost guage.

 

i had a problem like that in my 1982 280zx turbo 2+2 found out the tnak was full of rust had the tank fixed... still bakc fired changed out the fuel filter and spark plugs and i put in the good stuff yellow complete fuel injetor cleaner i think its called GUNK ... its a pertolium based i took my turbo car out on the road 75mph for about 50 miles.... and WOW fixed that back fireing problem...