I just bought a 1993 300zx tt auto, and the turbo gauge says its not boosting above 0psi. i have been told by a fairly reliable source that i need a new mass air flow sensor, is this true? or what else could this be?

Simple answer is no you have been misinformed, if the reading is correct at the gauge ie no boost above 0 then unless you have a massive boost leak which you would hear and the engine would run rubbish, you have at least one seized turbo.

 

Replacement is the only cure, a full check is required though before committing as in the main its an engine out job, expect £2k to £2.5k for the job with new turbo`s, depending on spec.

 

Bad luck bud.

 

Jeff TT

ah well thats a bit of a bummer, thanks for the help though, i have also been told that the ecu may have gone into emergency boost mode due to error codes being logged. chances are i have been misinformed ......... again

Only takes 10 mins for you to check for error codes mate, no harm in trying

smithy

Thats great mate, but im not quite sure how, i dont have datascan or anything, i just bought the car in good faith from a dealer called crest cars in high wycombe. im probably just going to take the car back to be honest because if it does have seized turbos then the dealer has lied through his teeth to me, he assured me that everything was as it should be!

Just a screw driver mate is all thats needed

http://www.ttzd.com/tech/diagnostictech.html

Let us know how you get on whatever happens.

smithy

Tried to get under the wood, but unfortunately one of the screw heads is so worn i cant get it undone. Phoned nissan to ask about a datascan/consult session, but they wanted £50 before they'd even plug in. been told a way to reset the ECU, so gonna try that next

I'd take it back mate, no boost on these cars is NOT good, stupid stupid question but it is defo a turbo model yeah? Obviously a boost gauge in an NA would read the vacuum and right up to 0... :)

Are you ever near NW London (Brent Cross)?

As an alternative you can do a code check via the Consult plug ( under the bonnet catch lever ) by using a paper clip to force the ecu into diagnostic mode, however I still think you will have a seized turbo based on your description.

 

Jeff TT

ah well thats a bit of a bummer, thanks for the help though, i have also been told that the ecu may have gone into emergency boost mode due to error codes being logged. chances are i have been misinformed ......... again

 

It would still boost in safety mode but not just the full 9 psi, I think around 7.

In a standard auto doing around 40mph or so if you floor it should feel rather quick to say the least.