KA24DE Help

[suckafrees13]

hi, i have a 1990 240sx coupe. it has a KA24DE with dc sports headers, injen intake and custom 2.5 inch exhaust. the problem i am having is that my car won't go pass 2500rpm. after some search i found many solutions, mainly a bad maf. here is the problem tho. the ecu gives out a bad maf code everytime, but the shop i took it to swap out two different mafs and it didn't do anything. sawp auto and manual ecus, didn't do anything. checked coolant temp sensor, o2 sensor, spark plugs, wires, rotor, cap. checked timing, checked injectors, fuel pump. nothing seems to be wrong but the car still won't go pass 2500rpm. super wired, so please any advise would be helpful thx.

[91white_ka]

Yeah that's almost deffinetly MAF related. If you trust that the shop tried good mafs then look at the wiring around the plug for the maf. Crappy connection somewhere possibly. A mod I personally do is to ground the maf to the chassis. Identify what wire coming of the plug for the maf is the ground, then simply cut and install a connector, then bolt it to the engine block or a good chassis spot.

[Walperstyle]

The only thing besides MAF could be the wires inbetween the maf and ECU, or the ECU itself.

[suckafrees13]

checked everything listed here, wiring is all solid. swaped ecu with both a manual and auto ecus, nothing. i know that the car is stuck in limp mode but can't get it out of it. another problem is that even when the car is completely cold, as soon as i turned the key to on or start the engine, the temp gauge on the cluster just shoots all the way pass H, and when i rev the car in neutral, the temp gauge jumps up and down. would a bad distributor cause me stuck in limp mode or the wired temp gauge reading?

[klits562]

The temp gauge problem could be a seperate problem, my temp gauge will work normaly most the time but anytime i start driving it drops to all the way down and wobbles up and down a bit. I know the gauges themselves go bad alot of the time, or it could be the sensor itself. Our cars have 2 coolant temp sensors, one for the ECU and one for the actual temp gauge. As for the MAF problem, find the voltage reading for a good maf and check your maf to make sure yours is giving off a good reading. If it is a good reading then check the reading throughout the wiring harness between the MAF and ECU to make sure the reading is steady all the way to the ECU.
If after that all is still good.... then idk

[suckafrees13]

hey guys. i got it figured out. for you who is having same issue but can't fix it by swapping maf and stuff. what happen to me is that the engine harness was behind the egine and it was getting pressed on by the egr tube causing some short in wires and messes everything up. pull the engine harness up and ziptided it and all working fine now.

[carcrzy920]

i would go through the part of the harness that was being pressed against the firewall to make sure that no wires were damaged. some bare wires could have been touching when the pressure was there and then seperated when you moved it. just an idea so this doesnt happen again while your out and about.