RB25Det Nissan Terrano

[Paulballz]

I have no idea why you can get it to run without the pump and with no fuel pressure. Something is very wrong. You need to go over the fuel system again. You fitted the skyline pump into the tank? I'd rewire it like megasquirt recommends too. If it ran in another vehicle it can't be much, you just need to figure out what you've done that's different to the skyline setup...
I'll admit it..I'm a bit stumped by it for now...

When the guys convert the rd28 laurel to rb20s they just fit either in tank or inline fuel pump and thats that... dont know what is different will try investigate. Still the fact remains though that some how the engine is running with no pump or pressure...is it possible that since the injectors are spraying at full throttle when pump is on it is leaving enough fuel that once pump turns off it carrys on running... Note this: to start the engine i turn fuel on and crank until it trys to fire sometimes it does fire but very cough cough, once fired then i switch pump off and it revs straight up to normal and idles. But it will not fire if i do not prime fuel pump before hand.
Another note that may be completey inrelavent. When i turn the engine off (not let it die) and turn the key back on i get combustion in the cylinder (when megasquirt turns on it sparks all plugs once, then carrys on once cas turns) so this must mean that there is excess fuel still in cylinder?? the compustion usually blows out the intake a puff of smoke or back fires out exhaust even though engine is not turning over

[Paulballz]

Thanks alot for your help you have gave me that bit of hope back that has been destroyed time after time

I know how frustrating it can be...I've just got My bike with the link in it going...with a very different setup to what it had. I've already killed 2 sets of iridium plugs in it and it's still hardly ride able.
Good luck with it, you'll get there

haha im glad im not the only one going through this...i would rather do the whole engine installment 100x over then try get this electrical side and engine running going

[DEATH_INC]

Except mine won't run with the pump disconnected...

[DEATH_INC]

Note this: to start the engine i turn fuel on and crank until it trys to fire sometimes it does fire but very cough cough, once fired then i switch pump off and it revs straight up to normal and idles. But it will not fire if i do not prime fuel pump before hand.
Another note that may be completey inrelavent. When i turn the engine off (not let it die) and turn the key back on i get combustion in the cylinder (when megasquirt turns on it sparks all plugs once, then carrys on once cas turns) so this must mean that there is excess fuel still in cylinder?? the compustion usually blows out the intake a puff of smoke or back fires out exhaust even though engine is not turning over

Is that correct? I wouldn't think it should do that. You're right in thinking there is excess fuel in there, it will kill the injectors when you turn the key off so there should be NO fuel in there. Now it's adding up. (maybe) Recheck your injectors. Make sure they are shutting off properly. Pull 'em out and plug 'em in and see what happens when it's all turned on. You should get a short burst of fuel if the engine is cold, then nothing until it's cranked.
Otherwise we'll wait for the vid.

[Dirtydog]

This is starting to sound like a wiring problem, maybe the pump is turned on when it says its off?

have you checked the loom out yet?

[DEATH_INC]

This is starting to sound like a wiring problem, maybe the pump is turned on when it says its off?

have you checked the loom out yet?

That's sorta what I was thinking, if it's wired wrong it may be backfeeding and running at odd times, but not properly....if you know what i mean.... Though he does say it doesn't show any pressure at the rail....

[Dirtydog]

but if there was no pressure at the fuel rail it wouldnt run?

is the fuel pressure reading done via electrical means? if its the ecu thats reading no fuel pressure at the rail and theres an electrical problem couldnt it be reading wrong?

[DEATH_INC]

but if there was no pressure at the fuel rail it wouldnt run?

Egg-sack-tlee, that's what's got me buggered too

is the fuel pressure reading done via electrical means? if its the ecu thats reading no fuel pressure at the rail and theres an electrical problem couldnt it be reading wrong?

I think (is it paul?) it's taken off a gauge on the fpr? So not electrical...

[Paulballz]

This is starting to sound like a wiring problem, maybe the pump is turned on when it says its off?

have you checked the loom out yet?

hey guys good to see iv got you all thinking...def not electrical problem as can physically hear pump start an shut off very well an as mentioned i even ran the pump in a bucket of fuel an watched the return line pump fuel once FPR GAUGe reached set psi... did this to eliminae odd chance that since my fuel tank is steel (not plastic like car) i thought maybe pump was effecting ground of truck which would stop injectors opening...no chang
e at all...so i qm pretty sure it is pressure overfueling problem hence truck runs with pump set ON but only when FPR s set at 0-2psi..it does run rough though...as soon as pressure s increased inslightess it dies...or turn pump off an it starts idling correct.....

look at the brand new plugs it pretty good indication of serious over fuelng would you not agree

[Paulballz]

This is starting to sound like a wiring problem, maybe the pump is turned on when it says its off?

have you checked the loom out yet?

That's sorta what I was thinking, if it's wired wrong it may be backfeeding and running at odd times, but not properly....if you know what i mean.... Though he does say it doesn't show any pressure at the rail....

will video everythng when work on it next to show im not crazy

[Dirtydog]

i dont know much about ecu's etc, but if its getting too much fuel could it be cause the ecus telling the pump to stay on too long etc?

im just guessing here, but who knows i might throw in a new line of thinking to the mix, hopefully helping out

[Tarmac]

Bad run of luck man, another left field idea - are you sure the injector resistance is set right in the ecu? if all else is correct then possibly way overfuelin at ... psi but with the pump off and 3.f all psi behind them its running ok - for a bit ie opening wayyyy to long. Read the last few pages and its got me stuffed ( it dosnt take much ) As I understand it this hasnt been run under any load etc? so if somethings a bit fudgey in the injection side of it you wont have been able to pick up on it yet? Sounds like a stand back n look at the big picture time as it dosnt seem to add up

[Paulballz]

i dont know much about ecu's etc, but if its getting too much fuel could it be cause the ecus telling the pump to stay on too long etc?

im just guessing here, but who knows i might throw in a new line of thinking to the mix, hopefully helping out

the pump is hard wired to eleminate problems with it...i was told to do this from tuner..as long as psi un FPR reg is correct then pump can stay on...am nearly positive it something to do with ecu settings which is telling car to pump way to much fuel...megatuner said to start lowering VE table (how much fuel injectors spray) be 10% increments am going to try this also...strange thing is this tune is fresh for rb25det neo so vaules should of been near correct.

keep coming up wth ideas this is process of elimination an my brain is fried from all the problems ticking over all day everyday

[Paulballz]

Bad run of luck man, another left field idea - are you sure the injector resistance is set right in the ecu? if all else is correct then possibly way overfuelin at ... psi but with the pump off and 3.f all psi behind them its running ok - for a bit ie opening wayyyy to long. Read the last few pages and its got me stuffed ( it dosnt take much ) As I understand it this hasnt been run under any load etc? so if somethings a bit fudgey in the injection side of it you wont have been able to pick up on it yet? Sounds like a stand back n look at the big picture time as it dosnt seem to add up

Yeah real bad run latley but small hurdes trying to stop me...this i have also discussed with tuner..my injecter pulse width is 3.5ms which he informed me was good...but i really do think there something fishy going on here..those plugs were caked an where brand new and ran for few minutes... def a stand back moment..

so my latest verdict...engine runs with no pump due to heavy over fueling before pump switches off. (i know doesnt add me so welcome to more possible reasons)...2nd verdict the injectors must be pumping huge amounts of fuel in due to ecu telling it to for some reason..this is why pump on it drowns the spark and dies....i cant come up with any other reason so please throw your thoughs in so we can tick them off and get this girl 4x4n

[philux]

Is the alternator hooked up and the running at the correct voltage? oldyella manage to corrupt the file when he made changes with low operating voltage, had to re load the code in again.

Alternator Fixed Up from Harrex downing & little in Dunedin

Caused myself some problems when I made some setting changes to the MSII when the battery voltage was low. Corrupted the entire code so then the MSII decided to pump so much fuel into the motor it hydrolocked the motor

So, drain petrol, change oil, re-loaded code and tune and back in buisness

[Paulballz]

Is the alternator hooked up and the running at the correct voltage? oldyella manage to corrupt the file when he made changes with low operating voltage, had to re load the code in again.

Alternator Fixed Up from Harrex downing & little in Dunedin

Caused myself some problems when I made some setting changes to the MSII when the battery voltage was low. Corrupted the entire code so then the MSII decided to pump so much fuel into the motor it hydrolocked the motor

So, drain petrol, change oil, re-loaded code and tune and back in buisness

Ahh this is promising...i had the exact same problem few weeks back an had to send ms back to tuner as it corrupted and filled cylinders with fuel...did not know how or why it happened...exact same problem as his one...this is one area i never
did confirm with alternator...my td27 and the rb alternator used the exact same plug so i didnt think twice and just pluged it in...i am unaware of voltage difference between the two...so to sum up my rb alternator is pluged nto the old td wiring

[philux]

i guess make sure its charging at 13.8 volts or whatever its ment to be, and that td27 and the rb are regulated the same eg, td27 internal and rb external = would now have un-regulated power supply. not sure what would happen if it was the other way around thou

[meatc]

Where are you picking up the earths for the ECU? You should have one (sensor earth) that comes from the same place on the engine as all the sensors/injectors etc and then the main earth direct from the battery.

I had issues with the engine in my toy (standard ecu) when I first set it up cause I had both earths to the ecu coming from a common body earth. Simlar but lesser problems that you describe with the over fueling. The small amount of voltage variation messes with things, remembering that a number of the sensors send signals that the ECU picks up in volt ranges of less then 1V and most sensors are running on less then 5V not the 13+V of the rest of the car.

[Paulballz]

Hey meatc, the RB engine has a section by the thermostat that is used (standard) for all the earths. I have ran my grounds for the following going there through 6 heavy wires... CAS / Boost Solenoid / Idle up / ECU / Coilpacks / TPS / Coolant sensor / VCT (these are the only original components used at this stage plus the MAP vacuum)...Some of the smaller gauge wires have been spliced into one connection. When i check this area for ground with multimeter against the 12v batt, i get the 12.41v (so guessing it grounding suffecient.

For my battery earth cable i have ran the standard TD27 wire, It bolts in the side of the block / bottom of battery tray / then - Battery. It also as a smaller gauge wire (about 4mm thickness) then runs from block to truck inner guard.

[jonossiksilvia]

To get an exact reading of wat the grounding is doing you should be measuring the resistance not the voltage

[Paulballz]

ok will try that so you mean measure the ohms?

Here is a complete wire diagram of how i wired the engine...Please look through it for any faults that are obvious remembering my electrical experience before this was limited to car stereo installs.

F=Fuse
MS ECU= Signal from megasquirt

Have checked all plugs to ensure they are getting 12v...
Note: Engine has run with this setup (althought not correctly)
Black hose is where i connecter MAP Vacuum line

[jonossiksilvia]

Yes ohms. Ie set to ohms on meter, put black wire on neg battery, put red wire on say a bolt on engine that has not got a rubber washer. If reads 0.00 means good earth no resistance.

Sorry very brief as on phone

[Dirtydog]

i think your onto something there,

and the turning down the fuel on the ecu may be something too.

[Paulballz]

well my fluke brand multimeter test showed
Ohms symbol selected
Black on NEG battery terminal
Red On Bolthead of Earth clamps then tryed earth wires

Key on =13.2
Key off = 1.2
Battery (Positive) disconected = 0.2

Guessing is this not good at all?

[jonossiksilvia]

Forgot to say touch leads together to make sure it goes to 0.0 first. Also check not just that bolt but as far as earth wires go ie ecu plug, sensors etc

[DEATH_INC]

Hey meatc, the RB engine has a section by the thermostat that is used (standard) for all the earths. I have ran my grounds for the following going there through 6 heavy wires... CAS / Boost Solenoid / Idle up / ECU / Coilpacks / TPS / Coolant sensor / VCT (these are the only original components used at this stage plus the MAP vacuum)...Some of the smaller gauge wires have been spliced into one connection. When i check this area for ground with multimeter against the 12v batt, i get the 12.41v (so guessing it grounding suffecient.

For my battery earth cable i have ran the standard TD27 wire, It bolts in the side of the block / bottom of battery tray / then - Battery. It also as a smaller gauge wire (about 4mm thickness) then runs from block to truck inner guard.

Am I reading this right that the main earth for the megasquirt is going to the same place?
If it is move it to the earth on the battery, or at least somewhere else.
It may not cure it, but it is better that way.

[Paulballz]

Forgot to say touch leads together to make sure it goes to 0.0 first. Also check not just that bolt but as far as earth wires go ie ecu plug, sensors etc

Yup it goes to 0.2 when touch terminals

Just rechecked again

Key OFF but both batt terminal connected = 0.5 that is on earths on engine plugs

Key "1" Click = 1.2 - 1.5
Key "IGN" (not cranking one before) = 13.4

Tryed multiple spots on plugs and engine and all come back similar results.

Testing body with key off comes back around 0.8

[Paulballz]

Ok have tryed that before will do again though run straight to batt earth

[DEATH_INC]

In fact, move anything that isn't a sensor earth from there (coilpacs etc), the sensors like a 'clean' signal.

[DEATH_INC]

Ok have tryed that before will do again though run straight to batt earth

Sorry, I may have to take that back...does the megasquirt have 1 or 2 earth wires? Most ecu's have a main earth and a sensor earth.
Do you have the V3? If you do the sensor earth should be pin 7, run that one to the block, on it's own bolt, and the others to the battery.