Gq rb30et r31 loom help

[duckygqpatrolrb30]

Hey guys this could be a mouthful but here goes.

Due to some melting and a little rushed wiring I've changed out the VL loom in my gq for an R31 loom. Heres where it gets annoying... I have it wired up with the typical pinout for this loom and no good news followed, I've run constant and 12V ignition still no go, she's fully earthed, still no go, I can get her to turn over but she won't fire, I spray some degreaser down the throttle and she wants to fire so I know I have spark, my issue is I don't hear my injectors pulse, I can loop the injector wiring at the ecu plug end and hear them pulse but I can't leave it in such a way. My earths are heating when I try and start and my positive terminal was hot as hell so I know theres a problem.

I've joined the usual pins but nothing, I thought maybe my ignition isn't giving enough constant so I switched the wire to battery, nothing. The 3 pin plug I'm not sure is even doing anything, I can bridge pin 6 to anything I like key on or off and hear the green eccs relay ping off its rocker. If someone has direct pictures of the R31 wired in to and from locations on an rb30et gq that would be great so I can double check every last tiny connection against the images shared.

I followed everything for it and the result is disappointing, I've read every forum post available and still no result produced, Pictures are worth a thousand words if someone can help I'd appriciate it.

[mudnut]

The main problem is manufacturers constantly changing things even on the same model. It sounds as if you have a short somewhere, or a faulty component. You may have to trace each wire from its source to its termination. I know it's a horribly tedious job but other than that...

http://www.nissanpatrol.com.au/forums/showthread.php?36470-RB30-EFI-Conversion

[duckygqpatrolrb30]

Any and all problems are welcomed, even the fixes people have done. I've been over this engine bay at the very least 40 times. Everything says I should have a running vehicle however I don't. Even if a problem isn't my issue it's possible it could indirectly be a contributing factor worth looking into.

I've spent so much time on this that I may very well be so focused on what it's doing and over looking the tiniest thing. Let's throw a hypothetical in the mix, I have fuel, I have spark, I have fire when I spray down the throttle but I lack fire when I don't spray into the throttle.... Is it possible despite having fuel everywhere it needs to be along with having all the components required to start that maybe fuel pressure is the issue? I mean lack of fuel pressure would ultimately neglect fuel coming through the injectors even if they were pulsing which would result in not firing correct?

Sometimes just seeing issues others have had, an image of where they connected, how they fixed it is enough to spark a brain storm. I've searched forum after forum after hundreds of relentless posts, it could even be that maybe the directions I've been following are incorrect but I tried direct battery and ignition direct for the 3 pin plug and couldn't get it to so much as send power to the ecu instead had to hard wire direct to the ecu pinouts.

[duckygqpatrolrb30]

After looking closer I have noticed I have little to no fuel pressure so I'm putting in my brand new FPE240 high flow pump, approx 70psi, 250L per hour delivery, e.g 4.8bar according to all the specs I have found and other users specs against manufacturer specs check out to being ok.

[mudnut]

Yes fuel pressure needs to be upgraded from the original pump used by the carby. Stupid question; since you replaced the loom, have you also deleted the low idle fuel return solenoid from the fuel system. It remains open at idle so the fuel pressure is not too great for the carby. It only closes when a signal is picked up by the Engine revolution sensor.

[duckygqpatrolrb30]

There's a good chance I haven't, I'm running the low pressure in tank and my high flow is in line at the engine bay so I can hear it and know pressure that end is fine. I have an issue though, I out mg high flow on an individual relay, constant when key is on, shuts iff when key does but theres still no fuel in the return line, I sat with the pump working and the return line disconnected and still nothing in the return 🤔

[duckygqpatrolrb30]

So even with the solenoid removed and the return direct to the fuel line I still get nothing at the return 🤔 I'm not sure where my fuel is going but it doesn't come out anywhere

[mudnut]

There should also be a timing circuit on the fuel pump relay, that allows oil pressure to take over and connect the pump. I found the circuit is dead on two I got from the wreckers as well as the one that came with the car. It is a safety for when oil pressure is lost.

Does the fuel regulator need vacuum to let fuel return to the tank.

[duckygqpatrolrb30]

It is a vacuum actuator in the middle of the inlet where fuel lines connect before it enters or leaves the rail.

I havn't looked into that but I will now, anything else I should be aware of? If she won't play ball within the next 2 weeks I'll have to send her to the shop. Could even be the ecu not performing correctly e.g needing auto electrician attention but the chances of 2 ecu's doing the exact same thing tells me that something is wrong.

[mudnut]

You need someone who has done the conversion to help you now. I've sent a message to one member who has done the conversion, but I haven't seen him on here for a while.

[duckygqpatrolrb30]

Muchly appriciated mudnut, thank you. It's starting to do my head in lol, same issue I had with the vl loom and ecu, changed the ecu and loom to r31 after the vl loom gave up on life and the same issue so I'm running out of things to look at and do 😅 I expected it wasn't going to be the most simple execution but I didn't expect an issue this big. If I can atleast get her to fire i'll be able to do anything else required to complete it. Auto electrician guys said I don't need to put the intercooler kit etc in for them to do their job so I have 2 weeks to get her going or she is heading into the shop, they asked what needed to be done so I told them about the loom swap to make less work and just needed her to run so I can complete the rest of the required stuff like my intercooler kit etc. Gave me a good price between $300-$500 so it's not too bad off if that's the route I have to take. I'm by no means inexperienced with electricals or conversions but this is my first with the rb30et and it just won't play ball 😬 I think it is something simple but it has me chasing my tail and I need to be finished before december as I am taking my kids to Queensland to be with family for the holidays instead of being stuck in Victoria lol.

[duckygqpatrolrb30]

You need someone who has done the conversion to help you now. I've sent a message to one member who has done the conversion, but I haven't seen him on here for a while.

Hey mate, an auto sparky confirmed a hit and miss issue with RB's, even with the entire loom powered and still powering while cranking the injectors lose all voltage in some cases however not many present with a way to diagnose it. I've now got injector pulse and spark after bridging the injector power to an in car fuse for the fix. Now I just need to swap the low pressure in tank pump with the high pressure pump to gain my fuel pressure for the RB30ET. I muchly appriciate you responding to my post, you gave me some food for thought.

[mudnut]

So glad you got it sorted, and posted your fix. It might help someone else in your predicament.

[duckygqpatrolrb30]

So glad you got it sorted, and posted your fix. It might help someone else in your predicament.

Absolutely, there's been quite a few bits and bobs I've had to do. I can confirm the fuel meiser fpe-240 can be used in tank as a single stand alone pump for the rb30e and rb30et conversion, held strong at 80psi in the rail so if anyone is out of idea's for fuel pumps it's a good way to go however if using a stock pump holder give it a 45° bend and run a 5cm hose cut off on it with a filter, this will sit it on the bottom of the tank with no pickup issues. Can confirm the build will run fine on an N/A R31 ecu. Change the fpr either turbosmart or another known brand will do you justice, I went with a saas rising rate fpr with a 100psi gauge and have had no issues with it at all however I made my appropriate adjustments while the car was running. There is absolutely no need to change the fuel pump relay or add an extra relay in for this let alone even cut anything on the loom (I cut because I heat shrinked my splices). If you're still using the gq loom for starter and alt this is fine, no modification to it is neccessary and the standard oil pressure sensor will work fine until you upgrade to a more reliable gauge or sensor. You don't have to run an intercooler to begin with aslong as you keep your boost between 1-8psi but I don't recommend that in any sense as the hot air direct can and likely will produce pre detonation.

I've seen a lot of people wanting to get away from the waterfeed banjo on the block the corse thread is 1.5 in size and you can get a hose flange to suit it if you wish to cut the alloy pipe to fit a water hose instead (have left the banjo on the turbo itself due to limited space) if low mount this really makes life a bit easier.

If you have trouble removing the auto spigot from the rear of the crank if it has one use butter or bearing grease and a half inch socket extension bar(worked a treat) or you can get a steel chisel and cut the face to split it.

On the original gq loom it is also suitable to use the coolant temp sensor if your not ready to upgrade to after market.

Can confirm all the gq front of enginer gear and brackets will bolt straight to the block if you want to keep the V belt instead of going to the vl ribbed belt. If you are a 4x4 mud nut like myself it is a fantadtic idea to change to the V belts because they push out the debris a lot better than the ribbed belt.

If fitting a FMIC you can keep your aircon if you make a slight pipe modification to the air condensor unit and remove the front center support bar and use the intercooler as the new support.

Making life easier on the safari snorkel front entry setup avoid the factory airbox idea's and go to an after market setup with a flexi air induction pipe to run from the snorkel to the new airbox, most come with 3" - 2.5" silicon joiners, 3" clamps, holding bracket, filter, housing unit and 3" in/out flexi air induction pipe. This will save a lot of stuffing around and cutting to fit to the turbo intake.

The standard AFM bolt end can be cut flush with a die grinder to the inner circle outter ridge which will give you about a 2.8" diameter right round suitable to fit to a 3" joiner with clamp to save buying the adapter online and waiting for shipping (there's nothing in these plastics that will hinder or damage the parts function), the standard joiner size for the regular clamp on end is 2.75" and the standard T3 turbo outlet will use a 2" joiner to plumb out.

If you don't wish to replace radiator hoses and radiator yet take your flanges for in and out from your gq engine, they will directly bolt onto the vl setup. The hoses for the heater tap are shorter and you'll be in need of sourcing longer pipes. Get a T piece to put in so you can run of that into a reducer and then to the turbo water return.

The oil return to the block is a 3/8 npt flange fitting and can be located at most if not all part supply stores.

If your running a high pressure fuel pump it isn't neccessary to have the check valve left on, most of these pumps have a back stop valve incorporated to reduce fuel coming back through the pump, unbolt this and fit a standard hose flange if your not ready to spend the extra money on parts to complete that kind of modification.


If anyone comes across this post and is in the process of the conversion feel free to ask any questions, I've done this all myself without visiting a mechanic or auto electrician. Don't be affraid to ask for a little help, I can even manage a few pictures if you get a little lost.

[mudnut]

All this good info is added to the Conversion thread.