help

[skdline63]

hey iv recently rebuilt my motor, i hav had it goin and done about 500kms since rebuild, its been running good. decided to top mount my turbo and get a new intake manifold before i get it tuned. so i got the new manifolds on and started it and i ran for about 30 seconds and then started missing then stoped. now wen i go to start it will try to start and just cough and spulter and wont go sounds like its running on 2 or 3 cylinders. iv sprayed start up in the manifold and it doesnt make any differnce still coughs and spulters, i done a leak down test no vac leaks, the fpr is standard, i changed afm still the same. iv checked the timing its fine. iv puled out the sparkplugs and there really dirty, wen i look down at the top of the pistons it very dirty down there. so i cleaned the plugs and put them back it and it will run for a bit then choke up again. im really stumped here so if any of u guys can help me out that would be awesome thanks.

[articzap]

Did you change injectors too?

[skdline63]

yeah i did but the ecu az been tuned for them along with a skyline afm and had been running fine before.

[240cadrifter]

maybe you could help me out as well. i have a CA18DET in my 91 240sx. me and a friend put it in about 2 years ago. took us about a year to get it to run good but when it did, it ran really good. then the waist gate got stuck and we sold the car. well i bought it back last week and put a new waste gate on it and its running weird. as far as i can tell its still set up the way it was when we sold it.

now to the important part. it will start up and idle fine. but as soon as i touch the throttle cable it starts to spit and sputter. like its not getting any fuel. we have changed out 2 MAF sensors and 3 TPS sensors and 2 ignitor chips and changed the fuel filter.

[articzap]

Spitting and sputtering is more likely spark blow out from to much fuel.

[themadscientist]

please tell my if you stuffed rags in the intake ports during the swap to keep crap out you remembered to take them out before putting the manifold on.

[skdline63]

do i need a FPR to get my fuel pressure right because all i hav is the standard FPR but it had been running fine with that for about 6 months?i did put rags in the intake ports but im sure i puld them out, would it run for 30 seconds with a rag in one or two ports? thanks for ur guys help.

[240cadrifter]

yeah but even if it was getting to much fuel it wouldn't react as fast as it is. like as soon as you touch the throttle it does it. im thinking its a sensor or wiring problem somewhere. everything on the car is stock other then the front mount. but we didn't wire up the diagnostic system so we can't read any codes.

[240cadrifter]

i have noticed something different now. and working on it but just wondering what you think about it. i think im using a KA MAF sensor and on the CA wiring harness there are 4 wires but you only wire up 3. well i can unplug the ground wire and it doesn't change the way the motor runs. i take the MAF sensor off the car as long as its still pluged in and it don't change anything. but as soon as i unplug it the car dies and when i put the ground wire to the frame the car dies as well.