4000 rpms... no more... less is okay...

[Yoshi]

Okay since you all helped me figure out my rack was bad I'm tempting my luck at another car question... Any how, so my car won't rev past 4000 rpm and spits and sputters and has no power.

Things that are new or good

Head
Valves
valve springs
Valve seals
valve springs
Retainers
Cams
Timing at cams timing at distributor
Distributor
Cap
Rotor
Plugs
Wires
Coil
Injectors
Fuel rail
Fuel pressure regulator
Fuel filter
Timing chain
Timing chain tensioner
O2 sensor
Maf
Knock sensor
Water pump
Thermostat

I'll be changing out the eccs relay (called egi relay on 240s) and ecu on tuesday.

Any help would be greatly appreciated I am stumped.

[P.Haire]

sounds like your car is in limp mode or you have a nasty vaccum leak.

[Yoshi]

I think it is a limp mode thing. I'll check all the hoses and and the manifold for a leak when I work on it Tuesday. I'm in class most of the day tomorrow.

Thanks man.

[P.Haire]

go unplug your battery tonight and leave it overnight.

[Yoshi]

I'll unplug it in the morning on my way to class and leave it till I work on it Tuesday.

[matts13]

year of car, engine and engine management.

[Yoshi]

good point sir... brain fart when I posted

1991 nissan 240sx stock ka w/ head studs 248/248 "hot cam swap" stock ecu.

[matts13]

i would look at your tps o2 sensor and knock sensor. and since it s nissan clean your maf to be sure. after you check those sensors it would not be a bad thing to check your fuel psi under load. a fuel up and run a car at low demand but when it is put under a load it fails.

[Yoshi]

The o2 and knock sensor I had on there were a few months old, I changed them anyway and had the same issues. I also tried two MAFs from working cars. I'm gonna look up how to check the tps.

It's possible the fuel pump is going out, I'll have to try another one.

[foilman]

Limp mode is almost always the MAF sensor (or its wiring). DO NOT drive the car long or hard like that and change the oil ASAP. It's dumping so much fuel that it will thin the oil very quickly. 2nd, would be the knock, which is almost impossible to get to, just disconect it to test. Actually, pull the codes, it will tell you what it is.

[Yoshi]

So I pulled codes and got the knock sensor code and turns out that the wiring had come out of the plug. We fixed it and only pull 55 which is all sensors good. How ever the car spits and sputters still. I am leaning towards vacuum leak. I'm going to take a propane tank and see if I can't find the leak. If that isn't it I guess I'm changing my fuel pump.

[Yoshi]

So I took a propane tank to my whole intake and everything and did not find a leak. My next step is trying a different fuel pump. I have been hesitant to do anything with the fuel system due to being mildly allergic to gas... Oh well just gonna have to deal with it. I think I will capitalize on this opportunity to order a walbro 255.

[ChadMK4]

yea, just get the Walbro and be done with it. Good investment.

[Yoshi]

Yeah, Ken at Enjuku hooked me up with the ISIS 255 pump for a good price so that should be on it's way shortly.

[jsquared]

If you havent already since fixing the knock sensor, reset the ECU overnight again. Ive had the ECU show code 55 but still pull timing like a mofo until I reset it.