This may be somewhat lengthy
TRUCK: 1984 Nissan 720 4x4 z24 stock engine 5 spd
ISSUE: Under heavy acceleration i.e. from a stop light, shift from 1st to second around 4000 RPM or 20ish mph, then the problem either occurs here in
2nd if you push hard or in the next gear. What happens is around 35mph the engine looses power like it runs out of gas, it starts jumping like it's about to die. If you let off the accelerator it will regain it's power somewhat however it will immeadatly display the same issue unless you give it a second. Now if you ease thru the gears shifting at around 2500 rpm each time you can get up to about 45 before the problem happens.Stuff i've done to try and resolve the problem:
1 - Replaced the fuel pump 4 times (I think this is not the issue as the voltage is getting there and it runs when it should) 2 - Replaced the Fuel Filter twice 3 - Replaced the Fuel Pump Control module (wouldn't even start one morning, this fixed that problem) 4 - Replaced PCV valve 5 - Replaced Spark plugs 6 - Cap & rotor / wires 7 - Air filter My assumption is a fuel problem however i'm not sure. I am somewhat hesitant in the carb area however my gut feeling tells me this is where the problem is. The engine otherwise runs strong and has run great between the fuel pump replacements, but the problem keeps coming back and the fuel pump I just put in didn't fix it this time.Thanks for all of your time and suggestions
Dan