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View Full Version : C.A.S Problem with my SR.. Need help


SassOfrass5
11-26-2012, 07:03 PM
i have a 92 sr20det in my s13. i bought the car already swapped, so wiring and everything was done by someone else. the car ran, idled roughly, and broke up at 4k, but always started right up. i replaced the clutch, and took the car for a spin, it idled a llittle better( i fixed some vaccuum leaks), but still broke up. i parked the car and went to get some new spark plugs. when i tried to start the car to pull it in the driveway to change the plugs, it would not start. it just cranks. i noticed the tach did not move when cranking, so i tested the tps. i get 12 volts at the c.a.s, gound ohmed out back to the negative of the battery, 1 signal fluctuates from .1 to 5 volts, the second signal is pinned at 2.9 volts.i have fuel to the rail, and spark at all 4 coils.
anything else i should look at before i drop $400 on a sensor? if a new sensor is needed, wheres the cheapest place to buy a new one, as i prefer not to use used? tia.

Tranzporter786
11-26-2012, 07:23 PM
check your maf make sure its connected properly and getting proper readings

dopplganger1
11-26-2012, 08:30 PM
both signals on the CAS should fluctuate from 0.1V to 5V when testing it like the picture below. and the cheapest place I have seen for a CAS is nissanparts.cc
http://i304.photobucket.com/albums/nn183/emomiles/cascheck.jpg
very bottom of page
NissanParts.cc - Your #1 Source for OEM Parts and Accessories (http://www.nissanparts.cc/catalog/?section=1009#3285)

wangan_cruiser
11-27-2012, 12:50 PM
U checked if your injectors are actually firing?

steve shadows
11-28-2012, 12:39 AM
You need to check the ground for the back of the ignition harness to the head and the firewall. Also check the condition of your wiring harness near the ECU, usually the front clip sets and harnesses are hacked to sht. I would also check for any vacuum leaks as well as seeing if your timing is waaaaay off as well.

SassOfrass5
11-29-2012, 08:58 PM
injectors do fire, the car wont even start with starting fluid. ground to the back of the head is good. maf connection is good aswell. how common is the cas going bad on these, i dont really wanna throw 400 into it and it not be the problem.

SassOfrass5
12-06-2012, 05:36 PM
both signals on the CAS should fluctuate from 0.1V to 5V when testing it like the picture below. and the cheapest place I have seen for a CAS is nissanparts.cc
http://i304.photobucket.com/albums/nn183/emomiles/cascheck.jpg
very bottom of page
NissanParts.cc - Your #1 Source for OEM Parts and Accessories (http://www.nissanparts.cc/catalog/?section=1009#3285)

ordered the part, and chose to overnight it. Its been 3 days and the part hasn't arrived. I verified that all my contact information is correct. Tried calling and it goes straight to a voicemail. No response to my email. Have you ever dealt with this company before? if so is this problem common or should i be concerned..... tia

brndck
12-06-2012, 05:48 PM
injectors do fire, the car wont even start with starting fluid. ground to the back of the head is good. maf connection is good aswell. how common is the cas going bad on these, i dont really wanna throw 400 into it and it not be the problem.

if the injectors are firing, then your cas is working.
cas provides the signal that tells injectors and spark plugs when to fire.

did you check them with a noid light to determine that they are working?

two things i would suggest, swap in a known good maf
make sure your charging system is functioning properly.

a bad maf will cause your engine to stumble/miss around 3-4k
so will an alternator that isn't charging once your battery voltage starts to get lower.