[ToiletDuck]

Ok, to start off I know enough about cars to replace stuff and general maintance but not a car gawd.

The car is a 77 280z, the problem is that when i push on the gas it starts to cut out and die. It only does this at lower to mid rpm's. The wierd thing is that it doesnt do it all the time, after its been runnin a while and when i restart thats when its the worst. The car was runnin perfect till this started up.

Some things i think might be wrong are either the fuel pressure regulator, fuel pump, or the air flow meter. Im on a realy tight budget so i figured id start w/ the least expensive first.



Thanks allot for the help, i figured id get ur guys opinions before i blow allot of cash that i dont have. Also any tips or suggestions will be more than welcomed, thanks again.

 

[ToiletDuck]

Oh, some other things.

I have already replaced the fuel filter.

Also when it starts to die it backfires out the air intake.

 

[curtf]

The experience I had with my '77 sounds nearly identical to yours... I ended up replacing the thermotime switch, the thermal sensor, the fuel filter, the fuel pressure regulator, all the injection nozzles, their associated electrical couplings, the ignition box, the fuel injection relay, the BPT valve and all the vacuum lines (I figured that since the car was 25 years old it'd need that stuff anyway)

The problem turned out to be a clogged fuel line right at the inlet screen of the fuel pump (where the fuel line attaches to the fuel pump from the gas tank). You most likely have alot of rust and other assorted solid pollutants in your gas tank that has accumulated over the years. You may have to take the inlet end of the fuel pump off to blow it out from within (be careful about losing the inner workings of the pump, and mark everything so you can re-assemble it EXACTLY as it came apart). I'm going to install an inline fuel filter just before the pump to avoid having to take the fuel pump apart again.

Hope this cures your problem like it cured mine!

_c

 

[ToiletDuck]

Thanks for the advice, ill try that in a sec. Gotta replace the stabalizer link and might as well try that while i got all the tools out.

 

[olmanriver280zxt]

Hey man, I've got an '83 280zxt, but my car managed to do the same thing yours was doing. The problem with mine was the air flow regulator, it's almost not the thing to mess with, but you can loosen the screw on the inside a littlebit and just play with it, and see whether loosening or tightening it will make it run better. In my own case I had to tighten it a little bit, it's a little plastic gear thing with a spring, so don't loosen the spring too much or it'll just spring all the way to nothing, then you have to start from scratch and tighten it up bigtime. Good luck man, David, memphis

 

[olmanriver280zxt]

Hey man, I've got an '83 280zxt, but my car managed to do the same thing yours was doing. The problem with mine was the air flow regulator, it's almost not the thing to mess with, but you can loosen the screw on the inside a littlebit and just play with it, and see whether loosening or tightening it will make it run better. In my own case I had to tighten it a little bit, it's a little plastic gear thing with a spring, so don't loosen the spring too much or it'll just spring all the way to nothing, then you have to start from scratch and tighten it up bigtime. Good luck man, David, memphis

 

[MarZia]

duckie
The low rpm miss as well as the back firing almost certainly points to misfiring! My guess is your rotor and cap either has moisture, or else is cracked!

 

[shane280z]

Valve Adjust. Dist. Cap&Rotor.Fuel Filter. N/C

N/C = No Comment.

 

[nrkrell]

I have had my 78 280 for 8 yrs, so listen to me OK? Right. Did you steam off your engine recently? Anyways for this problem of "reversed acceleration" I would check out the crude Throttle POSITIONING SWITCH. CLEAN AND ADJUST IT. REMOVE THE LITTLE PLASTIC COVER AND GO TO WORK. I would say good luck but luck is for fisherman.

 

[johnh240]

Other than timing issues, backfiring out of the intake is normally caused by a lean mixture. Could be either low fuel pressure OR more commonly air leaks. Check all vacuum lines and air lines on the engine including the duct between the afm and the throttle body. ALL air going into the engine MUST go through the AFM.