No Start… no injector pulse

SON240sx Automotive
1

---------------!!!THIS PROBLEM HAS BEEN SOLVED!!!----------------

I recently have been trying to sort out this issue with my S13 sr20det.

I replaced the entire harness with a wiring specialties harness brand new

the injectors are brand new

Here is the problem:

I had the car running and brought it in for an etest and it failed, so I ordered some new plugs, oxygen sensor and did not work on it for a while ( almost 2 weeks ). There was also a very large ice storm and very cold weather I did not crank the car over or touch it during this time and it was outdoors ( not sure if this is relevant but w.e ). After the parts came in i intsalled them and tried to start the car. It cranks but does not start.

The spark plugs are firing very strong, I went through the entire harness and moved all the grounds and power to where they need to be. The fuel pump primes and comes up to proper pressure etc etc.

But the fuel injectors do not spray at all. I have checked by taking them out and cranking the car and nothing happens at all. I have tested with a noid light and it does not light, I have checked the voltage and I deffinitely have 12v on the power side.

My test light shows that there strong power on the 12v side of the plug and some power on the other pin which confuses me. At no point is there any ground at the injector plugs while the key is in the on position ( with the key out of the ignition there is ground on the 12v side and nothing on the other pin ).

From my research and all the other tests I have done, I have found that it could be two possible things ( in my opinion )

  1. The CAS is not sending a signal
  2. The ECU is fried

I do not have another CAS to test if that fixes the issue nor do I have another ECU to see if that is the issue.

I have also followed an online guide to getting your SR to start and one of the steps states:

  1. is the red LED on the ecu lit? -> Yes

  2. Try to start the car
    Does the LED turn off while cranking -> No ( it goes off but quickly comes on and stays on, but i think it is supposed to stay off )

  3. The CAS is not reading

there are many more steps but I am stuck at this one

Can anyone confirm this, does anyone have any suggestions?

------------------!!!FOR ANYONE ELSE WITH THIS PROBLEM THE SOLUTION IS AS FOLLOWS!!!-------

Charge the battery lol

if your injectors are not firing while cranking the engine try this first.

put the car in the on position
hand crank the engine and either listen for the injectors to fire or use a noid light to look for the ground signal from the ECU in the injector plug. If you are getting a signal from the ecu and have power on the other then charge the battery and try starting it

I had a low battery and even with a booster pack the car still would not start.

The reasoning is that there was not enough supplied voltage and current to provide the starter and all the components with enough power to send the ground signal to the injectors

2

Sounds like you nailed it with the CAS

3

Took out the CAS today, spun it by hand and the injectors fired, and I could hear the ignition clicking ( spark plugs firing ), checked again with my test light to confirm that the computer was sending a ground signal and everything checked out. NOTE: this only occured when the car was in the on postion and I hand cranked the engine. Re did the timing ( took off the valve cover and such )… Checked again by hand and everything works…

HOWEVER, I tried to crank the engine and NOTHING, the injectors no longer fire, there is no signal… WHAT IS GOING ON HERE

I have read and have been told that maybe the orange signal wire is not providing 12 volts to the computer when in the start postion but will this cause the spark plugs not to fire???

4

I know when my battery is low, it cranks but doesn’t fire. When I clamp on the portable booster it fires right up.

Try another battery or boost it.

5

Make sure you have over 12 volts while the engine is cranking, also check all the connections on the harness especially where they are connected at the computer. Make sure all the pins (wires) are fully inserted into the connector.

6

I will try charging the battery i know it is very low ( proabably almost dead ) because I have to use a booster pack to get it to crank which is also probably low from all the cranking I have been doing lol

Thanks guys

7

PROBLEM SOLVED!!! It was indeed the battery being to low

Special thanks to Yuri at wiring specialties and to all you awesome people on SON240SX!!! Really appreciate the help