JKDGabe Posted December 9, 2002 Share Posted December 9, 2002 At least the first one is easy: why does my boost guage read -7 to 0 to +7? That is, why the -? Why doesn't it go from 0 to 7? Second: I'm having surging probs at about 1,500rpm, it drops to 1,000rpm when I have just a little pressure on the pedal and the boost guage rises to -3 or so. Yet when I really step on it it doesn't surge, it is really smooth! Is this boost related or not? Quote Link to comment Share on other sites More sharing options...
JKDGabe Posted December 9, 2002 Author Share Posted December 9, 2002 OK, that makes sense. But does that mean it's actually putting a drag on the engine? Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted December 10, 2002 Share Posted December 10, 2002 Pressure gages usually measure differential pressure, i.e. the pressure difference between your intake manifold and the outside ambient pressure. So "0" means you have the same pressure inside your intake as outside of it. Negative readings means the pressure inside the manifold is less than ambient: a vacuum. Quote Link to comment Share on other sites More sharing options...
Guest De Schmaydee Posted January 18, 2003 Share Posted January 18, 2003 ....first (before anything else)..get another boost gauge (the original is crap and after-market ones are cheap)... ....its hard to tell if your prob is turbo related....i really dont think so...there's only 4-5 little pieces of tubing and the wastegate servo that does the whole turbo thing.... ...on mine you definitly feel a "lunge" when the turbo boosts...i think you might have a leak somewhere ...but prbly not in the turbo hoses....does the gauge show +5 to +7 quickly?....i'd check all the other hoses (tubing) and particularly the hose going to the fuel pressure regulator....kinda sounds like a fueling/timing prob to me....s Quote Link to comment Share on other sites More sharing options...
Hybrid240z Posted January 18, 2003 Share Posted January 18, 2003 An NA motor sucks air through the intake manifold. A turbo, on a turbo motor, pumps air into the intake manifold and builds boost. So an NA motor will always mark negative on a boost guage. A turbo motor on the other hand works the same way as a NA motor at lower RPM and shows negative too. As the RPM goes up, the turbo spools and builds boost, it will start to go into the positive at a certain point until you get the full boost reading. Which is whatever you set your boost to. That is why you see negative at low RPM and it goes toward the positive at higher RPM. As to your problem, I don't have much experience with turbo motors yet. Sorry. Marcos Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.