wont rev past 4800, l28e

If your post does not fit under any of the other technical forums post it here
Post Reply
hairy1121
Posts: 17
Location: whangarei

wont rev past 4800, l28e

Post by hairy1121 » Thu Aug 07, 2014 7:18 pm

any help appreciated, my 280z seems to be down on power and when you rev it to about 45-4800 rpm it starts backfiring and wont rev higher. any ideas? good fuel pressure, new cap, leads, coil, rotor, plugs.

User avatar
reliablejunkie
Z Club Member
Posts: 188
Location: Riccarton, Christchurch

Post by reliablejunkie » Thu Aug 07, 2014 7:48 pm

Sounds a bit strange, have you checked all the sensors and their connections? I find pulling them off, checking the wires are still in its connector well and popping it back in can help with the process of fixing. It sounds like beyond 4000 RPM a lot of fuel is being added which brings to mind something related to Air flow meter or the throttle position sensor.

I hope this steers toward a problem.
Tristan
Someone had to make up for all the pollutants these hybrid cars are saving these days, so i cranked up the fuel pressure and let the engine roar.

1983 280ZX L20ET engine with an N42 head running on megasquirt ECU

User avatar
disruptiv
Posts: 217
Location: Cambridge

Post by disruptiv » Thu Aug 07, 2014 7:48 pm

O2 sensor?

hairy1121
Posts: 17
Location: whangarei

Post by hairy1121 » Thu Aug 07, 2014 8:38 pm

where is the o2 sensor? im not sure it has one. ill check contacts ect... tomorrow

User avatar
disruptiv
Posts: 217
Location: Cambridge

Post by disruptiv » Thu Aug 07, 2014 9:29 pm

Should be in your exhaust haha, down where the firewall hits the floor pan

User avatar
reliablejunkie
Z Club Member
Posts: 188
Location: Riccarton, Christchurch

Post by reliablejunkie » Thu Aug 07, 2014 10:23 pm

That is another option. My zed doesn't have an O2 sensor so I can't talk about that one but could be another possibility. In you car it will be either in the exhaust manifold tucked away or on the side of the exhaust pipe somewhere before it leads under the car. If it hasn't done it before and all of a sudden it now backfires after a certain point in revs then it will have something to do with the timing higher up in the rev range or possible sensor problem.
Someone had to make up for all the pollutants these hybrid cars are saving these days, so i cranked up the fuel pressure and let the engine roar.

1983 280ZX L20ET engine with an N42 head running on megasquirt ECU

hairy1121
Posts: 17
Location: whangarei

Post by hairy1121 » Mon Aug 11, 2014 5:41 pm

thanks for advice, timing was all over the place, timed it and running sweet now : )

User avatar
reliablejunkie
Z Club Member
Posts: 188
Location: Riccarton, Christchurch

Post by reliablejunkie » Mon Aug 11, 2014 6:15 pm

Ah nice one. It is always a good feeling when it runs well again.
Someone had to make up for all the pollutants these hybrid cars are saving these days, so i cranked up the fuel pressure and let the engine roar.

1983 280ZX L20ET engine with an N42 head running on megasquirt ECU

Post Reply