Brycey Posted November 1, 2006 Share Posted November 1, 2006 hey guys, hows it going? just thought i would post up to see if anyone has experienced this problem or better yet knows how to fix it!! the short story, i have had my 280zx off the road for about 4 or 5 weeks i guess, i put new extractors on, changed diff mount, fluid change all round etc, but because i put on new extractors i had to get the extractors welded to the existing exhaust... so this morning the drive to the exhaust shop was very loud one. i picked up the car about a hour ago and everything sounded great and felt really good. so i thought after being so long i might put my foot down alittle. i got out onto the highway, put my foot down from a stop and it quickly climbed to around 3k then all of a sudden CUT no more power. i immediately pulled over because i thought something had gone horribly wrong but after checking everything then checking everything again it all looked fine :| the car idles fine, revs fine and freely in neutral but if your putting it under load it will cut between 2800-3200, and its a very severe cut.. im assuming its a fuel related issue but the only thing i did to the fuel system was install a new fuel filter and replace the old engine bay rubber fuel lines ( and they are connected correctly). I tried it a second time to see if it was just a one off and it happened again but I kept the foot down and it was almost like a violent rev limiter for 3k, it would build, cut, drop, build, cut, drop etc. i found that you can reach any amount of revs you want if you baby it and climb the tacho slowly, it revs very freely and fast in neutral but once you select a gear and boot it (any gear) it just dosnt want to, this problem just occurs :S iv never had this problem before and its a big tease not to mention very worrying. any help would be fantastic as im keen to sort this out ASAP thanks for looking Quote Link to comment Share on other sites More sharing options...
tec280zx Posted November 1, 2006 Share Posted November 1, 2006 I would try unplugging the throttle postion senser (left side of the throttle body) and see if the car still cuts out at 3k. Quote Link to comment Share on other sites More sharing options...
naviathan Posted November 1, 2006 Share Posted November 1, 2006 Check the plug color. Sounds like you're running too lean. Quote Link to comment Share on other sites More sharing options...
Brycey Posted November 1, 2006 Author Share Posted November 1, 2006 wow you were right tec280zx! and i think i am running lean naviathan, i rebuilt the engine and converted to 5 speed around may this year and never had a professional tune done, but never had this problem.. im going to get a tune done in the coming weeks now that i have it back on the road it feels alot slower though.. so how come it cuts with the throttle position senser connected but it dosnt cut with it disconnected?? Quote Link to comment Share on other sites More sharing options...
naviathan Posted November 1, 2006 Share Posted November 1, 2006 The TPS is shorting between the contacts. Sometimes you can pull the black outer cover and it could have moisture or something else in the bridging them. Quote Link to comment Share on other sites More sharing options...
Brycey Posted November 1, 2006 Author Share Posted November 1, 2006 ill go investigate now.. is it just me or did unplugging the TPS make it slower? - or in other words, if i fix this problem will i get the power back or is it my imagination playing tricks on me thanks for this guys, lifesaver Quote Link to comment Share on other sites More sharing options...
naviathan Posted November 1, 2006 Share Posted November 1, 2006 Probably did make it slower as the ECU doesn't know when to increase fuel or decrease fuel. Right now with no TPS reading the ECU thinks it's in cruise mode constantly leaving you rich at idle (sluggish off the start) and lean at WOT (might stutter in higher RPMS). Quote Link to comment Share on other sites More sharing options...
Brycey Posted November 1, 2006 Author Share Posted November 1, 2006 thanks for that mate great to know, ill get right onto it and ill post up my progress when it happens, thanks again guys Quote Link to comment Share on other sites More sharing options...
Brycey Posted November 1, 2006 Author Share Posted November 1, 2006 alright well i just took it of the TB but cant figure out how to open it :S it seems to have 2 rivets on the back that follow through to a blank screw face.. how do you open her up :| also i should have mentioned that i rewired the intake manifold, thermostat etc while it was off the road to hide alot of wires etc but i checked it about 5 times just then and its all correct.. Quote Link to comment Share on other sites More sharing options...
Brycey Posted November 1, 2006 Author Share Posted November 1, 2006 its all good, all sorted a mate came around just a short time ago with his spare TPS and its all fixed and running great but as things go, the 4 day old intake/exhaust gasket has blown out on number 6 -this is the exact issue that caused me to take it off the road in the first place. not happy if anyone wants me ill be in the corner crying Quote Link to comment Share on other sites More sharing options...
naviathan Posted November 1, 2006 Share Posted November 1, 2006 That sucks. I don't think I've ever had an intake gasket blow out that quick before. But, as Z Cars go, if it's not one thing it's another. Quote Link to comment Share on other sites More sharing options...
Brycey Posted November 1, 2006 Author Share Posted November 1, 2006 yeah it might be the type of gasket i used this time around.. here is a pic, i used the bottom one as the top one is stuffed as you can see it was kinda alkward gasket matching as the bottoms on the new gasket were circle :| no idea why, but i think im going to get a full metal mesh one rather then this style for the new one.. it jsut really really sucks because i just got it all back together and running really well - for about 10 minutes then for this to happen.. really disapointing.. oh well i guess this topics mystery is fixed, thanks again guys massive help, have a good one edit - my gasket has blown out just above number 6, there about a 3-4mm gap no idea how it did it, but its done. Quote Link to comment Share on other sites More sharing options...
naviathan Posted November 1, 2006 Share Posted November 1, 2006 Number 6 intake or exhaust? If the intake I would venture a guess that you pre-fired due to being lean at some point and it blew out that way. If you haven't done so already, get a manifold stud kit from pallnet. It will make a huge difference in ease of install and strength. I'm using a paper gasket like the bottom one in your pic and it's still going strong. Quote Link to comment Share on other sites More sharing options...
Brycey Posted November 2, 2006 Author Share Posted November 2, 2006 heres a pic, the blown out part is very visable its on the exhaust.. im gonna go for a full metal one next time.. just a real kick to the bum for this to happen, its all gotta come apart again. so i think that im going to get a L24 EFI manifold and a new fuel rail. Quote Link to comment Share on other sites More sharing options...
naviathan Posted November 2, 2006 Share Posted November 2, 2006 Wow, that's odd. It must have been a weak spot in the gasket. Maybe it got creased in shipping or something. Anyhow, the intake/exhaust gasket isn't all that difficult to replace. I did the one on my ZX in about 2 hours with the thermostat and a few new hoses. A metal one should hold up much much better. Quote Link to comment Share on other sites More sharing options...
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