My problem is with a 1983 Nissan Hard Body 4x4, fuel
injected, 2.4 liter inline 4 cylinder that I think is call a KA24E. The
engine has 2 plugs per cylinder, has 140k miles and is a 5 speed. The vehicle belongs to my brother who is not internet connected.
The problem is that the engine cuts back to idle when it hits approximately
2500 rpm (the vehicle doesn't have a tach, so we're not sure of the exact
rpm). In other words, as he's accelerating through the gears, if he allows
the engine to reach that rpm, he loses power; it's like the engine is
idling.
If you continue to hold the gas pedal at that same position, the truck just
idles. If you "tap" the pedal, you can get back control of the throttle but
you can't get it above that rpm.
He tells me that it will do this in any gear but he hadn't tried it just
standing still, i.e. not under a load.
He has replaced the TPS and the Mass Air Flow meter as well as plugs, wires
and two coils.
The truck starts and runs fine as long as you keep it under that RPM.
I've read, somewhere, that that's the computer controlled fail-safe rpm. Maybe your computer is bad. I know mine did this until I replaced the maf. It could be that the maf your brother put in was defective. That's not unheard of.
HF
Your engine is the Z24i, not the KA24E. The KA is a single-plug, multi-port, SOHC engine.
Anyway, a possibility could be a faulty O2 sensor. A bad sensor can't interpret the change in exhaust flow through the rpms, and it could richen it/lean it, which could change the rpm. I'm not sure, but it wouldn't hurt to check it.
EDIT: I came to this idea, because I drove a car that was doing the same thing, and it turned out to be a faulty O2 sensor.
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I often tell people that I hate Fords with a passion... and I do. But honestly, I don't have a problem with them - they allow me to pay the bills, and keep myself fed!
if the truck is an 83 its not fuel injected, they didnt use the Z24I until late 85.
unless someone did a transplant.. anyway, I have a 87 pu Z24I and mine went into fail-safe, (it lets you limp the vehicle home) I had a bad injector, you might try a auto parts store to see if they pull up some codes..
good luck....
KA24E engine dies at speed
Linear Mode
