1991 240 serious driveability problems!!!

[buellblastin]

I have a 91 240 with a 97 engine i swapped in. It has been running extremely well for a few months and just recently it began acting up. Three weeks ago it started to lose power as if going into a "failsafe". My dad used to work in a Nissan service dept but it has him at a loss.

I replaced the coil and it fixed nothing. No obvious vacuum leaks, plugs are good, and best i can tell the wires are still in pretty good condition. I need ideas if any one can help me.

What it is doing is when I try to accelerate it pretty much falls on it's face. I may have about 1/10 of my throttle available when it acts up. My theories are something to do with the sensors or maybe something is out of adjustment. PLEASE HELP!!!!!!!!!!

[vancouverbc]

if you mean ignition coil on a 1991, they basically never fail .

maybe check the codes.

[fun240]

Sometimes it feels as if i have a small small power loss.

What i've done -

Replaced all distributor(Distributor King out of NY has LIFETIME warrenty Distributors)Replaced Battery and AlternatorSpark PlugsFuel FilterAir FilterKnock Sensor(Went out, Car would not start AT ALL nor run for a long period)Oxygen Sensor(Front)Distributor Wires

Might want to start with that, I still do feel as if i have a small power loss, every now and then. If the car takes a minute to turn over, try to replace starter as well.

If anyone else is around that has had these problems PLEASE POST UP what you've done.

[buellblastin]

Yes if anyone has had this problem please let me know. I have looked over some other things on the car but still haven't even made a dent in the problem. If I had the money I would just take everything out and start over.

[OldmanPurdy]

Will your car rev above 3000 rpm?

[buellblastin]

It will but only if I am just BARELY touching the throttle. If I push it much it just nose dives. I'm getting so aggravated trying to find this problem. If I can get another car going I'll park it and go through from bumper to bumper if I have to. I've already ruled out the ignition coil and plugs. The fuel pump is only a few months old and the fuel filter is a month old. (it was clean when I replaced it)

[buellblastin]

Okay i've experimented a little more today and when I go past 3000 rpm and floor the pedal it dies down till 3200 and acts like its on a harsh rev limiter.

[OldmanPurdy]

Okay i've experimented a little more today and when I go past 3000 rpm and floor the pedal it dies down till 3200 and acts like its on a harsh rev limiter.

K it sounds like your MAF sensor is having issues, when its damaged or otherwise not working the engine rpms are limited to 3000. There is a procedure outlined in the FSM for checking the sensor, do that before buying one since they are expensive.

[k_c_b]

D

K it sounds like your MAF sensor is having issues, when its damaged or otherwise not working the engine rpms are limited to 3000. There is a procedure outlined in the FSM for checking the sensor, do that before buying one since they are expensive.

Def the MAF sensor, mine did the same thing until i went to the salvage yard and picked one up for like $50 then it ran 100% normal again

[OldmanPurdy]

Yes they are very common problems on KA engines, I've had two go myself.

[koki]

hey kcb