SR20 crank no start, fuel injectors not firing

[Lenhoward]

Hey guys,

I'm trying to help a friend out. The car is a US spec S13 with an SR20DET swap. The engine , Link Monsoon X, and stock wire harness merged into the Link connector were installed at a shop, but they never got the car running. When I started digging into the car, I found that there was no power to the CAS, and when cranking, the Link was not seeing RPM or a trigger signal. I made a quick jumper wire and jumped power to the CAS. It now sees RPM and trigger signals, but does not start. It is also running up the 'trigger error' counter during cranking. I verified that the plugs are sparking and fuel pump is running, but the injectors are not firing. I then did a trigger scope the CAS and found a good pattern, but the voltage only goes up to roughly 3.5 volts. Tested grounds and found that resistance is about 0.5 ohms on the shielded ground wire. I then tested the other ECU grounds (pins 25 and 34) to the shielded ground (pin 7) and found that they have 0 ohms of resistance and seemed to be spliced together. 

Can all the grounds be spliced together and connected to the chassis, like this car is? Or is the shielded ground supposed to be separated and connected solely to the CAS? I attached the current base map and the trigger scope. Thanks in advance!

tim s13 10 30 23 no start.pclx Tim trigger Scope - 2023-10-30 8;30;44 pm.llgx

Here's a screenshot of the trigger scope, if that makes things easier.

 

tim crank no start 2.llgx

[jdniss]

The injector flow in Injector Setup is configured or 0cc/min rather than say 480cc/min, 740cc/min, 1000cc/min, etc

SR20 here configured for Trigger offset of -85 on G4X, the trigger offset in the map is 0.
Might be worth getting a timing light out to check base timing while cranking to confirm any Trigger offsets required.

Edited November 4, 2023 by jdniss
Trigger offset

[aerace_fab]

Set the trigger setup to "nissan 360 opto"  - 90 for the trigger offset and something sensible for fuel injectors if you don't know what injectors you have change the fuel equation mode to "traditional" with master fuel at 14ms to start off with. 

[Adamw]

The trigger looks fine, it has an aftermarket 24 slot disk in it so you will need to determine the offset with a timing light.  You only get a trigger error counter increment just as you stop cranking which is not unusual or anything to worry about. 

As jdniss states, you need to enter the correct injector flow rate.  

 

[Lenhoward]

Thanks guys! It was the flow rate keeping the injectors from firing. I'm a little ashamed that I didn't see that. Yes, I had forgot to mention that the OEM slot disc was switched out for an AEM 24 disc, which is why I had set up the trigger settings that way. I just was getting hung up on the fact that the oscilloscope was showing only 3.5 volts and wasn't paying attention to much else. 

Nevertheless, my fuel injectors are now working after changing the flow rate. The engine still won't start, but after doing a compression test, I unfortunately found an even bigger problem. The engine is toast, but that's gonna be between the car owner and the shop who did the work. 

Thanks again for the help jdniss, aerace_fab and Adamw! 

[Pojebany]

On 11/6/2023 at 3:26 PM, Lenhoward said:

Thanks guys! It was the flow rate keeping the injectors from firing. I'm a little ashamed that I didn't see that. Yes, I had forgot to mention that the OEM slot disc was switched out for an AEM 24 disc, which is why I had set up the trigger settings that way. I just was getting hung up on the fact that the oscilloscope was showing only 3.5 volts and wasn't paying attention to much else. 

Nevertheless, my fuel injectors are now working after changing the flow rate. The engine still won't start, but after doing a compression test, I unfortunately found an even bigger problem. The engine is toast, but that's gonna be between the car owner and the shop who did the work. 

Thanks again for the help jdniss, aerace_fab and Adamw! 

Hey I'd like to ask you a quick question.

I have a Link Monsoon G4x and a S13 SR20 in a USDM spec s14, but no harness to go with it. I want to put my car on this ECU over winter.

My current setup is a RS Enthalpy piggyback tune, with a Wiring Specialties Pro Harness. 

Do I need a partial harness or a full new harness, you mention the Link in car stated had a partial harness. Is that all I need?