nissandrift

Im new to these forums, but I have a 93 240 w/ the stock KA24DE and Im having problems. The problem started a few weeks ago driving home from school, my car stuttered whenever I got on the gas. It would eventually go away, and drive fine. I went and bought plugs, and ordered a cap and rotor. I put the plugs in and my car didnt rev at all, it wanted to die every time you touched the gas. It felt like my old 91 when the MAFS went bad, so I unplugged it, and my car ran great until 2500 rpm's. At 2500 the ECU would go into safe mode. I checked the ECU for codes, and I got code 12. Code 12 basically states its a MAFS problem, so I ordered one. Over the last few weeks I've put in 3 MAFS besides my original, but they all performed the same. All of them visually looked fine, so I checked my wiring. My harness on the MAFS is getting 14.5 volts going in , 0.02 volts on the ground, and .4 volts sending to ECU. I've been told it should be sending around 1.2 volts at idle, does that sound right? On another forum I was told to check the ground wire and piggyback it, but it didn't help. I've checked the ECU a bunch of times for codes, to see if there was a change but it still gives code 12. I also made sure the gap on the plugs was right, but returned the cap and rotor for money to buy the MAFS. Anyone in the Raleigh, NC area have a 91-94 running KA24de willing to try one of my MAFS or let me try theirs? Anyone have a suggestion of what I should try next? Also when I put in the new plugs their seemed to be moisture on the spark plug boots, but I don't know if thats normal or not. I drove the car the other night, and got about 5mpg whick left about a quarter mile of smoke. If anyone wants to come look at the car or help work on it, feel free. Any ideas of any kind to check would be very helpful. Sorry for the long post, and if you'd like to IM me its ETSUrider.

nishioSX

what color was the smoke? bluish white or just white?

was there oil on your plugs? do a compression test, this will give you the most info if there is something wrong internally.

check your TPS also. that may be faulty. check the wires also for brakes. get a can of CARB. cleaner and clean the MAF and the throttle body....also clean inside.

check your C.C.V.V. crank case ventalation valve. if this is plugged, youll get alot of problems. clean the the inside of the hose and the valve with CARB. cleaner

check your spark plug wires. if there is a tiny break in them, it can arc. this sometimes causes the problems your having.(it did to me)
check the resistence in the wires through the cap..and also in the coil(primary and secondary windings). procedure is in the FSM.

hopes this helps..
aaron

nissandrift

Thanx for the info I'll try that when I get back from school, I forgot in the post that I've cleaned the MAFS already. I have a few sets of plugs left from my 91. so I'll try those.

nissandrift

The smoke is black, but carbon actually comes out the muffler. I checked the wires, put different plugs in, and changed the oxygen sensor. The old plugs didnt have any oil, just carbon. Where is the C.C.V.V., and throttle position sensor located in the engine bay? Without the MAFS plugged in the car runs strong until 2500, so I doubt its anything but a sensor.

hitokiri_808

it sounds like its an electrical problem. a wire might be grounding out somewhere.

nishioSX

black can mean 2 things...too much fuel(rich) or your burning oil.

you should start from there.



aaron

devnull

Sounds like you've got a problem with the wiring harness. Check the resistance of the wires at both ends of the harness.