S14 - runs but dies after 2 seconds

[Nathanj1142]

Hello all. I know it’s not supra related hence why it’s in this section of the forums, but me and a few pals are really at a dead end here just wondering if anyones got sr20 knowledge

I’m trying to help a friend get his s14 zenki (sr20det slant top) running. The main issue is the car will crank but not fire - sometimes can get it to run for a few seconds before the fuel injectors stop firing. This is usually achieved by unplugging the ecu coolant temp sensor, aswell as the maf chassis ground.

Back ground is: car ran fine but pulled the engine to spray the engine bay and do some welding underneath.the car is running a Apexi ecu with a z32 maf, and r8 coilpacks. Believe there are larger injectors on it to. None of these have been changed since the car last ran and idled fine.

We’ve checked all the earths and continuity checked the pins at the ecu side of the loom, I noticed that the ecu power wires have a slight resistance to chassis ground which I traced to the relays that are used for the NATS system (think it’s called eccs?) but a look on the Nissan wiring diagram shows that’s how they should be wired. Tried some different relays but still no change. The nats is 100% disabled when attempting to start the car as when the button is pressed on the fob, the fuel pump primes and fuel pressure is seen at the FPR.

we did notice using a node light, when the car does start up, that the injector pulse slowly dies out after a strong few pulses almost like the ecu is fuel cutting. Due to not having a cable and the software to check the ecu we cannot check engine codes. Checked the voltage on the tps, all fine there, maf has been swapped for a new one, checked the wiring over and over again, cas wiring checked

has anyone had a similar issue ?

cheers

[Noz]

Fitting a 2jz will fix the issue.

You're welcome.

[Nathanj1142]

44 minutes ago, Noz said:

Fitting a 2jz will fix the issue.

You're welcome.

I’ve offered my spare GE to him but he won’t do it :(

[Swampy442]

Sounds like ECU to me, you need that cable to check the codes

[Big Supes]

I'd physically clean up the earth's again and give it another try. 

Also check over the wiring loom for damaged or split wires. Unfortunately, these days with our older cars the looms can harden up with all the heat cycles and become quite brittle. Moving the loom around from taking the engine out could have disturbed it.