sudden power loss - 280zx

[Brycey]

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 :x not to mention very worrying. any help would be fantastic as im keen to sort this out ASAP

 

thanks for looking

[RUSSJZ-ZED]

Check/ substitute

1) fuel regulator (vaccuum hose?-unlikely-if not connected/perished, probably have to much pressure)

2)fuel pump

3)try another filter

4)Fuel lines-did a line get pinched when it was jacked?

[Brycey]

Check/ substitute

1) fuel regulator (vaccuum hose?-unlikely-if not connected/perished' date=' probably have to much pressure)

2)fuel pump

3)try another filter

4)Fuel lines-did a line get pinched when it was jacked?[/quote']

 

thanks russ

 

i just found it that its nothing to do with fuel which really confused me :? if i disconnect the throttle position sensor then it will run fine and not cut but there is a subtle yet noticeable power loss higher up.. im gonna check all the wiring and the module too see if anything is bridging and causing this short.. very interesting

 

but i know what you mean.. checking the pressures, lines, flow, vaccum hoses etc was the first thing i did but everything was in order..

[Brycey]

quote from hybridz

 

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).

[dave_hl]

Brycey, After my Wolf 2D went spacco and the fuel maps etc went all over the place i fiddled with it enough to make the car driveable to get to the tuners so they could sort it out. and i remember it did the same thing; it was right on either 2k or 3k revs, i think it was 3k. i thought i had set the rev limiter wrong but that was up at 7k.

 

the symptons sound the same though, it would kinda cut and then rev up and cut out and rev up and to get past 3k revs youd have to hammer it and try to just sorta push through that range till it gets better.

 

The guys at the tuners were a bit confused by it as well, but eventually managed to get rid of whatever was doing it by, i think, just keeping fiddeling with the ECU control thingy.

 

they did end up replacing by spark plugs (just incase) and then found out my ignition coil was defective because at idle it was only firing on 2 cylinders. (Remeber when i came to buy the car in Newcastle and when it was cold it would nearly stall then pick back up again, well thats fixed.)

So anyway i dont think the ignition coil was what was wrong there with the cutting out at 3k, but woudln't be suprised if it was some sort of ECU problem... although yours is stock is it not?

[dave_hl]

Just re-reading part of your post brycey, from memory mine still did it when sitting in neutral and wasn't varied under different loads, that didn't seem to change it, so sounds a bit different to what i had, but the "violdent rev limiting" sounds very similar.

[Brycey]

hey dave, glad to hear your ontop of the issues! will be great to have that zed running nicely, its had everything done to it just needs the management! hehe

 

yeah i think i can definantly narrow it down to the TPS because it cuts when connected but dosnt cut when disconnected.. iv got a mate coming around now who has a few spare TPS's that ill chuck on.. hopefully have some luck *fingers crossed*

[Brycey]

yup it was the TPS replaced and running beautifully again

but i just found that my 4 day old intake/exhaust gasket has blown out. wonderful.