Rb25Det Fault Finding Help!

[nismad]

Hi, I've been trying to get my RB25DET S1 started as it's been sitting around for a few years, so far i've cleaned the fuel tank, put in fresh fuel and she's turning over but not even a hint of spark, i've took the CAS off and turn in while ignition is ON and when I do the fuel pump activates but I cant hear the injectors clicking

I found an awesome post by Elite (below, HUGE! thanks btw) but being a noob im a bit confused, i'm about to check the plugs/coil packs for spark individually as outlined in the post, but would like to clarify how exactly i'm ment to check power to the coils, will i disconnect the plug from the plug and check the voltage to the wires or can this be done without removing the plug/coil??

You need to have checked ALL of the following properly:

Spark on ALL cylinders

Injection pulse on ALL cylinders

Compression

Fuel pressure

Check engine bay fuses and under dash fuses. With a 12v test light - don't just eyeball them from 1ft away

IF you have missing spark on any cylinders, check power to coils. If you have 12v then check earths. If you have good earths as well then swap coils to see if the spark moves to a different cylinder (only if you have spark on at least one cylinder to begin with)...otherwise swap them all out and check spark again. If you have no spark, but have 12v, check CAS signal (see below) and then check continuity back to the ECU

IF you have no pulse, check 12v at injectors - ALL OF THEM. If you have 12v but no pulse then check CAS trigger signal back to ECU with a scope or check RPM signal in ECU. If you don't have a scope you can swap CAS out but that's a dodgey way to check it. There is such a thing as two broken CAS's in the world. If you still have no pulse and a good signal from the CAS, then check continuity back to the ECU on both wires to make sure there is no breaks. If continuous back to the ECU on both wires - replace ECU

IF you have no compression - rebuild

IF you have no fuel pressure, remove the fuel filter and check it with a gauge (no exceptions - gauge or take it to a mechanic), If you have no pressure still with filter off, check 12v to fuel pump while priming. If no 12v is present then run a dummy wire to the boot and see if it fires up. If you have 12v but no pressure, then replace the fuel pump

If you have spark and injector pulse ON ALL CYLINDERS, fuel pressure, compression, no blown fuses and it still won't start, put some new spark plugs in it because you have probably fouled the shit outta them. Any plug will do. 4's will work. 9's will work. As long as they are new and they are a spark plug that fits

When you can put a tick next to EVERY item, then we can continue but I can assure you, if you perform all those test you will find your problem. If you don't do even ONE of those things, don't come back here asking for more help. Those are all the things you need to find your problem. If you don't have the equipment, borrow it or take it to someone who knows what they are doing. There are plenty of good import mechs in Victoria

EDIT** - One more thing, physically check ALL hoses for splits or if they have come off. If you are not sure, remove them and reattach them to be sure. You will cancel out the possibility of a major air leak AND you will learn a lot about your car at the same time

[nismad]

futhering testing shows ECU fault code 55 (good to roll) and tested the spark plug closest to the CAS sensor is getting good spark, so from what I can gather due to spark but no injector pulse and no fuel smell from the cylinder after cranking when the plug was out is that it's fuel related... unless I've missed something?

A quick history of the car might help to explain whats happend...

The RB25DET is in my 180sx and I upgraded the S13 pump to a Bosche 040 intank pump, this required the earth lead to be grounded near the pump to give full voltage, the car ran well for after the install but over time cold start took longer to fire up, i've connected the pump directly to a power supply and it seems to provide a consistent fuel (no spluttering etc) but havent had it tested, i've also disconnected the feed line into the engine after the fuel filter and get the same solid flow of fuel.

Is there a way i can test the injectors with taking them out so I dont have to replace the O rings?

And what would be causing the injector's not to pulse?

[DVS JEZ]

Use a test light to see if there is power at the injector plug when the key is on. 1 wire on all injectors should be powered. Will be the same colour on all injectors.

Then u need a noid light or LED test light to see if the negative trigger (the other wire on each injector plug) has a signal from the ecu when cranking.

Let us know how u go and will tell u what to try from here

[The Dan]

If you have 12V at the injectors and they are getting a pulse (tested with noid light - available at any repco or autobarn for about $10-$15) but the injector is not delivering fuel, the internal solenoid is seized. Now this is a tricky one - not difficult in practice but a difficult scenario for me to offer advice on - you can lightly tap the body with a screwdriver and hammer to try to activate them (get a friend to rotate the CAS while you do so it is trying to fire at least). Sometimes the jolt will free them up. If they free up, I HIGHLY recommend taking them out and having them cleaned and flow tested. Injectors that have sat for months will usually always seize unless stored in lubricant or fuel (bad). If you tap them, they start working and you can drive your car....I take no responsibility for melted pistons because you didn't take them somewhere to have them cleaned and checked. The fact they were seized means they cannot be trusted.

[BH_SLO32]

If you have 12V at the injectors and they are getting a pulse (tested with noid light - available at any repco or autobarn for about $10-$15) but the injector is not delivering fuel, the internal solenoid is seized. Now this is a tricky one - not difficult in practice but a difficult scenario for me to offer advice on - you can lightly tap the body with a screwdriver and hammer to try to activate them (get a friend to rotate the CAS while you do so it is trying to fire at least). Sometimes the jolt will free them up. If they free up, I HIGHLY recommend taking them out and having them cleaned and flow tested. Injectors that have sat for months will usually always seize unless stored in lubricant or fuel (bad). If you tap them, they start working and you can drive your car....I take no responsibility for melted pistons because you didn't take them somewhere to have them cleaned and checked. The fact they were seized means they cannot be trusted.

+1. Whenever I do an engine conversion I ALWAYS have the injectors cleaned particularly if the engine has not been started for an extended period. I upgraded the fuel injectors on my car once with some second hand injectors and had them cleaned before installing them and all 6 were found to be either completed blocked or substantially blocked. Good advice worth considering.

[nismad]

Use a test light to see if there is power at the injector plug when the key is on. 1 wire on all injectors should be powered. Will be the same colour on all injectors.

Then u need a noid light or LED test light to see if the negative trigger (the other wire on each injector plug) has a signal from the ecu when cranking.

Let us know how u go and will tell u what to try from here

I have tested power to the injector on the closest injector to the CAS and all is good

If you have 12V at the injectors and they are getting a pulse (tested with noid light - available at any repco or autobarn for about $10-$15) but the injector is not delivering fuel, the internal solenoid is seized. Now this is a tricky one - not difficult in practice but a difficult scenario for me to offer advice on - you can lightly tap the body with a screwdriver and hammer to try to activate them (get a friend to rotate the CAS while you do so it is trying to fire at least). Sometimes the jolt will free them up. If they free up, I HIGHLY recommend taking them out and having them cleaned and flow tested. Injectors that have sat for months will usually always seize unless stored in lubricant or fuel (bad). If you tap them, they start working and you can drive your car....I take no responsibility for melted pistons because you didn't take them somewhere to have them cleaned and checked. The fact they were seized means they cannot be trusted.

I made a noid out of a 200k resistor and an old LED i had lying around and it seems to give a solid pulse when cranking, just about to try the rest of them now. If they are all pulsing, then thats either seized/clogged injectors and they need cleaning or replacing right?

I want to upgrade the injectors anyway, so i could just buy new ones, i assume a remap of the ecu is a requirement?

[The Dan]

If you correct fuel pressure, power to injectors and pulse, power to coils and spark but the injectors are not ticking when you turn the CAS over by hand with IGN on, then yes, most likely cause is seized. give it a little tappy, tap tap taparoo.....

or just replace them yes

[DVS JEZ]

Haha. Havent heard a Happy Gilmore reference for ages.

[The Dan]

Haha. Havent heard a Happy Gilmore reference for ages.

Oh you like that!?

[nismad]

Update: All injectors tested ok for power/pulse, so i found some enthusiasm and pulled off the plenum collector and took off the injector rail, rather than getting stock ones i wanna get some 500cc+ injectors, i was looking at the safc II as a temporary measure until i get the cash to get a PFC.. but just out of curiocity, would driving around off boost cause issues with the larger injectors installed (as in drive it 30min to the tuners)

[SargeRX8]

Yeah it might not even start, if it does you will be rich as a rose bay Jew.

[DVS JEZ]

Should start but will be clouds of black smoke out the exhaust. And the plugs will foul if u try and continually run it.