my ca lives kinda....

[rchboy]

well my motor starts, but will not rev past 2,000 rpm. i have an safc2 hooked up to it and im not getting much of a maf reading. i have tried settings ok 2in 5 out and 2 in 7 out, but does not reading does not go above 3% and 1.7-2 volts. I have tried a z32 maf and a maxima maf but symptoms stay the same. with safc disconnected runs the same. with maf discvonnected it runs a tad better. in any setup car idle fine and dies as soon as the throttle is touched.

i have a gt28rs turbo on it and dsm injectors, splitfire coil packs, and tomei fuel pump, aeroquip regualtor set around 43 psi. The ecu is showing code 34 which what what i have researched is knock sensor, but no other codes.

Any and all help is appreciated thank you gentlemen

[rchboy]

i played with this issue a bit longer tonight and found a loose connection on the knock sensor, the reved a bit better for like 30 seconds or so and they started dying out. i check the codes and now im getting a code twelve which is for the maf if i have reasearched right. if anybody has experienced this before and that can shed some light on the situation it would be much appreciated. thank you for any and all help.

[biosehnsucht]

set your fuel pressure to 36.3 psi relative to ambient (easy way: hotwire the fuel pump relay by removing the relay and connecting the contacts together w/ a wire, then put ign to on and you can play with it relative to ambient air pressure) set it a tad higher rather than low if your gauge is not very high res and/or you don't trust it, say 37-38

if you can't rev past 2k your MAF is toast, or your wiring is. I don't know anything about SAFC tuning so can't help you there other than to check all the wiring.

make sure your knock sensor is properly wired, since you are throwing a code for it.

edit: replied and found you had replied yourself

[sideways danny]

seen this before, I'd say your ECU was suspect

[ca18datsun510]

its runs fine when its cold with the safc 2 in, 9 out.

as soon as it comes up to operating temp, the idle dies down, and the throttle getts very touchy.

also, the maf sensor harness was extended by a supposedly reliable source. the oem harness uses a shielded wire for the maf harness, the wire used to extend it, is not shielded.

would this cuase a problem?

[rchboy]

ok guys i got rid of the maf code with a brand new bosch maf, and got rid of the knock sensor code by adding a wire to the harness. the car runs great while cold but when it warms up it doesnt run at anything but idle. i tried getting a new o2 sensor but that didnt work. i checked the o2 wave pattern with an o scope and it was good and double checked the maf wiring and that was good. now im getting code 55 which is no codes at this time if im not mistaken. that code kinda leads me to the cpu but im not sure. so if any of you guys can help me that would be great and if i can provide anymore info to help with the diagnosis i have no problem suppkying what i can. thank you for the help.

[daniel577h]

same thign happens to me. if i doesnt run when warm check all your sensors for closed loop operation

[rchboy]

checked maf signal, tps, knock sensor, o2 sensor, and coolant temperature sensor. they are all talking to the cpu. i tried a different cpu today from my friends swap and same results. any engine speed off idle the car falls on its face

[biosehnsucht]

check for vacuum leaks? maybe something is only leaking once heated up..