Japtastic141

Thanks for coming back to it. It does seem so doesn't it being nearly a volt drop. Well, the cable was actually run in Japan. 12AWG. I've checked both ends and the complete run when I've been doing other things in the car with back seats out etc. I bypassed the relay completely the other day and just hooked it up direct but with the same results. I've run a new earth direct to the plug to a tested decent place about 12 inches away. Bought it a few months ago from JDM as I knew there were a lot of fakes on eBay / Amazon etc.

Yes

Got the clamp meter and Picoscope out today. 12.5A with no accessories on at idle. With AC, Fans, Rear De-Mister and Headlights on it's around 26A. So it appears that the alternator can provide enough amps although I'm not sure how much higher the amp draw is when driving. Getting around 10A testing the cable at both the battery and fuel pump end. I also ran a new temporary lead direct from the battery to the pump to check if that made any difference but it didn't. This is less than the specs of this pump though. They list 14.1A at 13.5v....

Did you mean decrease? I've only seen decreases in voltage to match the fuel pressure declining. Thanks for the tip on the 5D fuel. I had the fuel pump out yesterday to remove the damper and at the same time checked everything and all looks good. It's a walbro 450lph, pulls 14.1 amps at 13.5v. Just done what you mentioned with the pump set to 5 bar fuel pressure at idle. 13.8v At The Battery 13.4v Link 13.2v Relay Feed In 12.92v Relay Feed Out 12.85v Fuel Pump Connector If I bypass the relay I get the same on road results and the following: 13.04v Feed 12.85v Fuel Pump Connector With the car off the battery reads 12.75v and the exact same voltage when testing in the boot for the feed to the pump. Not sure where to look next...

Ok done and that has improved things in that I get return flow now. My results for that are: 4.6 BAR @ 25 seconds = 1150ml returned x 2.4 = 2760cc Based on Adam's post, 450BHP would require a successful test to be above 2700cc so I'm within spec there. I really thought that was going to do it so went out but still the same :( https://drive.google.com/file/d/1LbbTR0FKTtQIc2U49VsjY2upxYsp1HDT/view?usp=sharing You can see the battery voltage does dip by 0.5-0.6v during this. Not sure if that was spotted before and could be causing this?

Doing it now

This thing? If so, yes.

Just replaced the FPR and T piece for an 8mm one but still the same issue so I tried your return fuel test. The fuel flows back nicely when the FPR is at 0 reference but when I apply some pressure from the air compressor to the FPR boost reference port the return flow stops completely. So I believe I've found my issue but why would it be happening? Just a recap for continuity. The pump (along with a direct positive feed from the battery and chassis earth) sock, filter and FPR have been replaced with new items.

Thanks, Adam. Ok, I'll fix that now. I did note that the readings matched the gauge max memory function in the car and the max that the link recorded. I took some voltage readings at 2.5, 3 and 3.5 bar and extrapolated the rest. Shouldn't that work especially as it looks linear? I'm all for changing old for new when needed but if I can get this setup to work it would save some money and waste of an otherwise good part that's already plumbed in. How about my 8mm-6mm-8mm fuel plumbing?

It should read bar so that’s what you are seeing in the logs. I’ll adjust it in Link to display correctly but I don’t think too important at the moment. It matches the gauge in the car. It’s a Greddy sensor. The FPR is unknown. No markings or numbers on it that can be found to identify it. Thanks for that return test info. I saw a few people mention it but not the method to do it. I may have found something that is contributing (or the cause?) to it as well. You’ll have to tell me how significant it is. Where the fuel pressure sensor is connected uses a T piece with a 1/8 NPT for the sensor line but then the two connectors for the fuel lines are 6mm ID rather than 8mm ID that the rest of the fuel system uses.

Decided to get some new injectors as I wasn't convinced these 20+ year-old ones were still reliable. So this has meant a retune to accommodate them. That's fine and I feel like I have that process sorted (so ignore the general mismatch of AFR/Target AFR) as I'm still going through that process but I still have an issue with fuel pressure at higher rpm's. It tails off right towards the end of the map, hence my map needing more fuel rather than less in that area. I thought it was the FPR so took that off and it was leaking from around the adjustment screw. I sorted that with PTFE tape so was hoping that was the cause but doesn't seem to be but maybe the FPR is still at fault? I've already replaced the fuel pump and sock + fuel filter in the engine bay and the pump has a direct + feed from the battery bypassing the FPCM and new earths to the chassis. I did leave the pulse damper connected in the fuel tank. You can see here what it does. TPS and Boost are the same but dropping off at the end which of course pushes AFR well out of range. 3.2Bar drops to around 2.8. Any other tests I can do to figure this out or is this all pointing towards the FPR https://drive.google.com/file/d/1dJ5j2NHweEFK3gwidQXCMBfCsIbZg-09/view?usp=sharing

Can't believe I messed up the Mode selection. I blame lack of sleep! The rest was correct. I was messing about with the streams before so the actual cal file I'm using has that right. Glad it was simple. Thanks, all working now.

I've been through the Evans videos and Link help about this and followed it but I can't get any output to the G4X. Analog 0-5v works fine if I set it up that way. I have my own connectors and believe my wiring is correct? I've tried CAN1 and 2. Also tried moving the power off the CAN2 connection in case it was that but still no joy. Also tried with and without the 120ohm resistor. G4X R32 GTR-REV20-New AFR.pclx

Thanks both, lots to consider. I also don't know how reliable this guage or sensor is after 20-30 years. What kind of temp do you normally see at idle? This might tell me at least if the sensor/gauge is in the ball park. I'm seeing 300c ish.

Thanks. I'll be sorting out the det cans soon so will be able to start working on the ignition timing. No loop as I upgraded the harness so used the trigger wire on the first coil pack. Yeah, that was my thought as well. It's only by chance that I have the gauge.

I have no idea what's normal for an RB EGT wise. EGT not on the log but here it is anyway. https://drive.google.com/file/d/1X5Q9c1t8pCOMmEAnYJPyi9HoaHEEe4Gy/view?usp=sharing

Thanks, will do. Does ECU logging look any better? Looks about the same to me. BTW Went out and logged some more and looking pretty good across the board imo. Well happy with the way the car feels. Turned the boost back on to 1 bar and did some hard pulls. Worked a treat and still tracked AFR target well! EGT's max out at around 1050c

Brill thanks. Can I presume the change to IAT fuel trims / and or a swap to the new sensor may mean a few tweaks of the map again?

Ok cool, will look in to the IAT. Factory location ok or worth spending the time moving it? Got you and that makes sense about the logging and CLL. Cheers, appreciated it, just emailed.

Thanks for looking again. What does fat mean? AFR seems to be tracking well I thought. Ok, glad the map shape is looking better. Standard IAT. Should this be replaced/moved? Ok, will make some changes to the IAT fuel trim table. I'm just using the standard base map from link so whatever came in that is what's in mine. They are coming from the laptop logs. Anything I check or troubleshoot for that? The latest map I've tested/logged is the last one I posted. I have a new iteration now just with the tweaked fuel map again. I'll be testing and posting a log for that tomorrow. Here is the unlogged map in the meantime. REV16 - G4X R32 GTR+OLLC ON-AMS AFR-3rd changes.pclx

Ok so I think my 50-100% TPS runs are fairly good now? Did a few and they match fairly well and AFR's track pretty good. If I get them all to within what I have below is that considered ok? I've worked on my 10-40% TPS area after seeing the log. That whole area of the map needed a few % taken out of it. The 3D shape roughly stayed the same though. Still not getting a taper-off at the top end of the fuel map. Fuel pressure increased to around 4-4.2 bar on full power runs and doesn't drop near the top end / redline. https://drive.google.com/file/d/1guOFCBuTnZ82_vRB03udr2Jhw6VVh-Zj/view?usp=sharing

You could well be right. I'll spend some time on it and let you know. The EGT sensor does put out ohms in relation to temp so not sure why it doesn't work...

Not sure actually. I'll check on my run shortly. I need to see if there is a way to take the data from the Greddy boxes output or directly from the sensors and pull that into PC Link via ohms or voltage. I tried the EGT sensor direct to PC link on AN Temp 3 but it's not working. The EGT sensor puts out ohms and I have some recorded vs temp and put that in a table but it's not recording correctly. I haven't spent any time troubleshooting but it's next on my to-do list as if I can make it work it will give me the ability to log fuel pressure, oil pressure and EGT.

Cruising and idle is 13.5v, steadily drops from the start of a power run, and ends at 13v minimum. It's what looks like a Nismo FPR and has been adjusted to run around 0.5 bar more than standard from what I can tell on my Greddy FP gauge. 3 Bar on idle, 3.6 bar on idle with vacuum pipe removed... Sorry, not sure what you mean.

Going to take one more look at this morning to make sure I've done the best job I can on the map and just to see if it turns out similar to last night's attempt for my own sanity! No, I've run a new cable directly from the battery to relay in the boot and bypassed the FPCM completely. Also fitted a new fuel pump around a month ago. Could injectors cause this to be skewed in your experience? Coupled with the fact the dead times may not be accurate...