RB20DET problem after warming up cant figure it out!!

[duele]

Ive had this issue with my RB20DET in my 91 240 sx. Tell me if this sounds like a MAF problem or FPR problem or something you have had happen to you. One day I changed coil packs and plugs because I had that bad miss problem. To my surprise everything was awesome after new install car pulled strong under full boost through all rpms. Then one day after boosting steady through out the day I stop at a red light and the thing suddenly was like it was running on 5 cylinders. Under acceleration its rough and hardly no power. also smoke out of exhaust. gas smell. I checked for clicking in all injectors while symptoms were happening everything seemed good. I have good spark I dont know whats going on. UPDATE car runs GREAT cold no matter what. Soon as it warms up this happens. ESPECIALLY after say driving under boost then parking it, turning it off for a half hour then restart it runs like CRa%$P. PLEASE HELP!!!!

[duele]

anyone??~?~?~

[C33_RB20DET]

i think it could be your MAF...but i have a problem something like it and i changed my MAF and that didnt work..so now i'm thinking about getting the fuel tank cleaned and pressure testing the fuel pump after it warms up...best bet it trial and error becasue i dont think there's any other way if the engine didnt come with the car original...you should try a MAF from someone you know or from one of those used parts places....

if you go to a used parts place just tell them you'd like to test the MAF before you buy it and take out yours while you there and leave it with them and try out their own..go for a spin and see what happens...thats what i did

hope you get the problem fixed...ine is still acting up..so tomorrow maybe i'll try to get the tank cleaned and pressure test the fuel...you can check out my post too..maybe you can get some ideas there as well....

RB20DET Cutting Off and Holding Back ---->that's my post...good luck.

[DriftingisLame]

An easy way to diagnose heat related problems is to drive the car and heat it up to full temp.

Pull sensors/actuators that you suspect may be the problem ONE at a TIME. Throw em in the freezer. Leave them in there for a bit, but not long enough to get much condensation built up. Soon as you put the cold sensor in, if it was the problem, the car should run properly momentarily.

[onepuff]

What kind of coilpacks did you use as a replacement? New or used? Sounds like a coil pack problem to me. Are you sure you are getting a spark when this is happening?

[duele]

I do not have coil packs at all. I run a coilpack from a buick 3.8L series II wired with my ignitor amplifier. I then run wires to the plugs. The symptom was there when I had my coil packs as well though. Tested all coil packs they work fine. Im thinking a key sensor is failing upon heating up. Today during aceleration it would run fine for a sec then back too crap then back to fine while just climbing rpm range in third gear so something is crapin out and common back on . thought it was 02 sensor so i disconnected it and went for a drive symptom still came out after 15 min but it was a bit worse this time. When I unplug MAF (mine is a z32) car almost dies then revs back up when i plug it in same thing. unplugged tps didnt change anything..im so lost.....

[Yellow4g63]

Bad coolant temp sensor? bad CAS? ecu throw any codes?

[s13X2r32]

i think im having the same problem.i read codes 12 and 34maf and knock. i have switched maf with no change after warming up.a replaced ecu with a stock rb as well and problem returned.

on new ecu car ran ok with no codes for about 30 miles no as bad as before the maf swap/

my next plan was to pull knock sensor i guess but idk if that wil do anything.

new fuel filter too.i my experience coil packs feel more like a miss where this is a complete lack of anything. the sound becomes hallow and stalls. the idol is between 1300 to 2000.op does your do anything like that?

[Joe]

i think it could be your MAF...but i have a problem something like it and i changed my MAF and that didnt work..so now i'm thinking about getting the fuel tank cleaned and pressure testing the fuel pump after it warms up...best bet it trial and error becasue i dont think there's any other way if the engine didnt come with the car original...you should try a MAF from someone you know or from one of those used parts places....

if you go to a used parts place just tell them you'd like to test the MAF before you buy it and take out yours while you there and leave it with them and try out their own..go for a spin and see what happens...thats what i did

hope you get the problem fixed...ine is still acting up..so tomorrow maybe i'll try to get the tank cleaned and pressure test the fuel...you can check out my post too..maybe you can get some ideas there as well....

RB20DET Cutting Off and Holding Back ---->that's my post...good luck.

please fix your signature image, its too large

zerothread/203223

[duele]

I pulled my codes today..... Im getting code 21 Ignition Circuit . I pulled the spark plug wire off of cyl 1 while it was running and in crap mode warmed up and I got some clicking noise so I put it back on can ran perfect. for about 5 min. then same thing . If I do it to cyl 2 it does nothing. I unplugged CAS while running and it shut down is that right? im trying to narrow this down. Maybe my ignition amplifier is shot or is going shot ....

can I check for voltage before and after the ignition amlifier to see if cyl 1 is getting signal to the amplifier and what comming out on the other side of the amplifier. Does anyone know what the voltage reads should be from the ecu to the amplifier than from the amplifier to coil?

[USMCgetsome]

its in the FSM! also, keep in mind if your seeing white smoke this would be a sign that something is burning. Smell the fumes for a few seconds and figure out what it is. If it smells like fuel pull the rail and replace with new o-rings.
Modified by KUILLIN_DRIFTER at 7:11 AM 9/20/2008

[duele]

FSM what the heck is that?

[s13X2r32]

FSM what the heck is that?

field service man. great way to learn lots.

[duele]

The actual shop manuals? where am I going to get my hands on one of these...?

[s13X2r32]

The actual shop manuals? where am I going to get my hands on one of these...?

it is on nico, they have every shop man for every skyline and rb made i think

http://www.nicoclub.com/FSM/rb/
Modified by s13X2r32 at 11:17 AM 9/20/2008