Guest Anonymous Posted October 7, 2002 Share Posted October 7, 2002 Guys, This may or may not be a Turbo specific problem, but here goes... I've got a mysterious power and throttle response problem. I've tried about everything I can think of and need some advice on what else I should check. Recently, my stock '83 280zx Turbo developed a strange power and throttle response problem. I'm not aware of any "event" that would have caused it. The engine was running fine right before the symtoms started. The power and throttle response is normal at low speeds, and low throttle. It cranks and idles perfectly. The boost is smooth and goes straight to "7". But, the power curve drops off significantly after boost gets into the positive range. Also, when I let off the throttle, the power drops off instantaneously, which is unusual. It's almost as if the exhaust suddenly got clogged, but I know that's not it because I disconnected it at the CatConv, and that doesn't solve anything. I've got a fuel pressure guage installed, and it says about 40 psi, but I can't see it while driving. Another strange thing...after driven hard for only about a minute or two, the turbo's exhaust housing gets hot enough to glow, and I don't remember that ever happening before. I'm thinking "Holy Crap", I've leaned it out somehow, and maybe done damage. But it hasn't pinged once. Does retarded timing cause these symtoms? The timing is set normal, and I didn't tamper with it before the problem occured. Could the ECU somehow not be advancing the timing under high boost/high RPM? But what would cause the ECU to do that? One observation: normally, when idling, if you had removed the oil filler cap, the engine would die. Now, it just slows down some, and idles just a bit rough. Since the problem cropped up, I've: Replaced the Turbo (it needed replacing anyway) Tested the AFM, and even tried another one. Tried another set of plugs (not related...I know) Tried another distributor Tried another ECU (from an automatic 280ZXT) None of these made a difference. This makes me think it's something mechanical, but I can't think what it could be. The only part I haven't replaced, that I think could be suspect, is the fuel filter and the fuel pump. But the fuel pressure seems the same as it was before. Help....I'm STUMPED. Thanks, Shawn Boozer Louisville KY '72 240z '83 280zx Turbo Quote Link to comment Share on other sites More sharing options...
Guest RENN TURTON Posted October 7, 2002 Share Posted October 7, 2002 Sounds like you have developed a vacuum leak. I would check all hoses. With my car I found that my leak was caused by a loose exaust bolt at the rear of the manifold. Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted October 7, 2002 Share Posted October 7, 2002 Check in your other post re mystery turbo death. Quote Link to comment Share on other sites More sharing options...
Sean 83ZXT Posted October 8, 2002 Share Posted October 8, 2002 Try using some electrical contact cleaner on all your connections to the ECU. I had a similar problem and that solved it. Quote Link to comment Share on other sites More sharing options...
Turbo280Z Posted February 4, 2006 Share Posted February 4, 2006 could check ur EGR too Quote Link to comment Share on other sites More sharing options...
Mex-Z-can Posted February 4, 2006 Share Posted February 4, 2006 Connect a a/f ratio gauge to your oxygen sensor and go for a ride. If mix gets lean during boost, then you have a fuel delivery problem. Remove the fuel filter and try to blow through it. Air should flow almost freely. If not, then you need a new filter. Look for obstuctions in the fuel line and tank. If all this is OK, your fuel pump may be bad. Quote Link to comment Share on other sites More sharing options...
nienberg.11 Posted February 4, 2006 Share Posted February 4, 2006 I'm almost certain your turbo has died, or is well on its way there. If the bearings were shot, the turbo would be very difficult for the motor to spool, causing all kinds of heat and power loss to get it into boost. Also, I've never had my turbo glowing at all. There would have to be some serious problems for it to glow red hot after only a minute of driving. It's likely that your bearings are worn out, filling up with coked oil, or have been starved for oil somehow. Edit: I didn't see that you had already replaced the turbo, but have you considered that the problem could be oil delivery and the new turbo has been damaged? Quote Link to comment Share on other sites More sharing options...
EZ-E Posted February 4, 2006 Share Posted February 4, 2006 I would check the timing, just to be sure then check for vacumn leaks and fuel pressure while under load. Go through systematcially to find the fault to your problem. Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted February 6, 2006 Share Posted February 6, 2006 Are you guys looking at the dates og the orginal post? I think it's done by now. Quote Link to comment Share on other sites More sharing options...
EZ-E Posted February 6, 2006 Share Posted February 6, 2006 Awe come on now, its only 3+years old, Im sure he still has some issues Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted February 7, 2006 Share Posted February 7, 2006 Try using some electrical contact cleaner on all your connections to the ECU. I had a similar problem and that solved it. + 100 This is ALWAYS the first thing you should do! When 280zxt wiring harness start to age and corrode, they often give exactly these symptoms... car looses power in boost, sometimes bucking and surging violently. it's the cheapest easiest thing you can do and it seems in 9 out of 10 cases of this problem it solves it! had this happen to me numerous times myself. 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.