Sr20det CAS test results

[mr.nismo.]

Ok it's been awhile since this motor has me stuck but I am unsure of these results as the FSM test is very vague on what they're supposed to be. I have a rich condition to the point I'll misfire even out of boost. I've checked all the normal shit, no boost leaks, fuel issues, etc. ignitor checked out fine. I have ecutalk and when I pulled up the ecu readings it was off. All the sensors were reading normal but the timing was bouncing between 9 and 15 degrees at idle. When the 9 would bounce you could hear it miss slightly. I had my mechanical timing set to 17 degrees. The ecu talk told me I had code 34 and 11. My 34 code never fucking goes away but the 11 had 11 starts since not showing the code (before that it was 6 starts) so I figure I should do the test. The FSM says between .1-5v fluctuating. Lowest was .2 and high was 5.3. However as I spun it it was all over the place between .2 and .8 then for a split second would be between 1 and 2v and then for another split second the 5v would come up and go right back. Both the 180* and 1* test came back with similar results. Is it supposed to bounce around like that? Or more of a smoother transition? The FSM doesn't state so hopefully someone here has done it or if they have a spare CAS to test? Thanks !!


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[Kingtal0n]

I have a rich condition


1. how do you know the engine is rich as you never mentioned wideband
2. if it is indeed rich then examine this: maf->ecu->injectors
We should look at our maf sensor (anything that affects the maf: boost leaks, misplacement, clogs, broken wires, insects, wiring, grounding, shielding etc) and do the same for all items along the route to the injector through the ecu

3.finally multipliers such as cts, iat, O2 comp, throw a global percentage and need to be considered, their sensors and programming, (although this is not mentioned here because programming is part of tuning and we assume you do not have a way to adjust these set points manually)

[mr.nismo.]

1. how do you know the engine is rich as you never mentioned wideband
2. if it is indeed rich then examine this: maf->ecu->injectors
We should look at our maf sensor (anything that affects the maf: boost leaks, misplacement, clogs, broken wires, insects, wiring, grounding, shielding etc) and do the same for all items along the route to the injector through the ecu

3.finally multipliers such as cts, iat, O2 comp, throw a global percentage and need to be considered, their sensors and programming, (although this is not mentioned here because programming is part of tuning and we assume you do not have a way to adjust these set points manually)


I indeed have a wideband. It goes rich as in 9.5:1 on normal acceleration, no boost. I've already cleaned and tested the maf, and the ecu reading is where it's supposed to be as well. The cts, o2, are not going to make it run this bad, and the cts is 2 years old either way (and is giving a correct reading ) and so is the o2. I mentioned checked the normal shit, like boost leaks and what not. I have a wiring specialties pro harness. Stock ecu.


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[mr.nismo.]

Also injectors are not leaking and are about 5 months old. Fuel pressure is where it's supposed to be


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[mr.nismo.]

Well CAS is back in. It was a bitch to get 15* it was all over the place but I got it set. Probing terminals 1 and 2 at idle give me .7 and 2.5 which is within range but it's erratic AF still. No ones done a CAS test before???? I just need to know if the reading is as erratic and jumpy as it was


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[Kingtal0n]

If the engine is turning over and firing on all 4 cylinders the cas is most likely fine.

I suggest you look again at the flow chart for fuel:

maf -> ecu -> injectors

fuel pressure/injector O-ring are variables outside the loop, the cts/o2 are variables inside the loop. If this was my car, I would boost leak test, followed by replace in this order: MAF, ECU, Injectors to find my problem.