Ka24de Won't Rev Past 2500rpm Stutters! Safe mode?

[Ninefive240sx]

I really need some advise. I just bought a 1995 240sx Ka24de 5-speed. It cranks, but in idle it only revs to 2500 rpm and then violently stutters almost like a rev limited. Same in gear, shakes the whole car.

CEL was one but I pulled only one code: MAF sensor. I shelled out $200 for a new one, installed it, same exact issue. CEL is still on...

Also, the timing chain is audiably ratttles... I know from a nissan dealership "undone work service recommendation" that I found in the glovebox that it needs timing chain and tensioners.

The car runs the same way (poorly) with or without the ECU fuse installed.Is this a "ECU fail safe mode?" Also, running extra rich... exhaust smells like unburnt gasAny idea's? Thanks!

[onosqv]

Yes, it's in safe mode.

Most of the time, if the car is rev limiting @ 2500 RPM or so, it's the MAF. And as you said, you pulled ECU codes and got MAF sensor.

After you replaced the MAF, did you pull codes again to make sure it went away? Could also be related to the MAF wiring.

Considering you just bought the car, it could be a lot of different things. Check to make sure base timing is correct, check the distributor cap/rotor, check the spark plugs, spark plug wires, fuel filter, air filter, o2 sensor. Half of that list would just cause poor drivability/idle, but you might as well make sure everything maintenance wise is up to par.

Wouldn't hurt to do a compression test either.

[TwoFoutyEsEx]

try resetting your ecu to compensate for the new MAF

[Ninefive240sx]

Thanks.... I tried resetting the ECU (unplugged the ground for several hours?) and when I restarted I have the same issues. I haven't repulled the codes yet (my buddy has the OBDI reader) but will repull tomorrow... I can hear the timing chain making a rattle though and it's running really really rich, also distributor cap might have oil in it according to the prev owner. More tomorrow... thanks again everybody

[kashan]

dude did you ever find out what was wrong with your car cause mines is doing the same thing

[jeu510]

if all is good, check for a clogged cat....that will also cause that problem...i can throw a maf code if the exhaust system gets backed up far enough to the intake...
Modified by jeu510 at 10:50 AM 6/2/2009

[sjrose247]

well the timing chain thing needs to get corrected for sure caus enothign would be worse then thinking you got it fixed just to hear a bang and need a cylinder head (trust me i just heard that bang... not a good sound ) after thats done then worry about your issue.

As far as the timing chain goes youd probably be best off taking it in... i looked into this myself and its a HUGE job especially in a driveway

If you still have the MAF code check the wiring, make sure its getting power and ground and sending a clear signal to the ECM. also check for proper continuity from the ECM to the MAF disconect both connecters use an ohm meter and see what you get.

Keep us updated on whats going on with this!