R34 GT, rb25de+t neo, cranks but won't start

[BrokecaR34]

Hey there, new to modding world of Link ecu wise at least, looks like my odd mishmash monster doesn't want to start.

Fuel pump is is running direct power mod and relay, fuel injectors, ignition tests all seem to have passed okay, spinning CAS pulled off but plugged in sends spark and oddly enough sounds like its opening the AAC valve? Unless that's intentional. 

No fault codes either, currently no IAT sensor, but in the books for future, 4 bar link map sensor wired through oem AFM on AN volt 1, with a 5v source teed from the TPS.

Logs look really wonky with the trigger error numbers and messy looking trigger scope, but unsure if did that wrong.

 

 

 

PC Datalog - 2023-08-28 7;35;30 pm.llgxTriggerScopeLog2.llgx

 

Files attached for viewing pleasures, thanks! Anything helps at this point, its just cranking til the engine floods or batt dies at this point =(

[Adamw]

Can you attach a copy of your map.  Your trigger error occur when the battery voltage drops below 6V so that probably wont be an issue when your battery has more charge in it. 

Your log shows no fuel being injected so you have the fuel mode set to off most likely. 

Have you set base timing?  If not, try your offset at around -90 as a starting point.  

 

[BrokecaR34]

Will try this and come back to you, I believe I was trying to test ignition after cranking to start didn't work and turned off fuel to stop flooding and do diagnostic. 

[BrokecaR34]

Nissan R34 GTT G4X Xtreme Plugin fueling edit test.pclx

i do believe the main thing ive only adjusted is the injector dead timing, they are bosch ev14 650cc injectors, otherwise setting offset to -90 didn't seem to help. 

My battery has just been relocated to the trunk, could this be grounding issues? I've got it ground to the seat belt bolt at the back seats about 30cm from the battery, positive cable is ran down the driver side to a distribution block feeding everything at the front as per OEM, both 0 gauge and resistance test showing less than 1 ohms from negative terminal to anything metal block wise. 

fuel on cranking and trigger scope captured mid crank updated logs

 

TriggerScopeLog4.llgx PC Datalog - 2023-08-29 1;54;34 pm.llgx

[Adamw]

Everything looks happy in that log.  Your master fuel setting is possibly still a bit on the small side for 650cc injectors, but there should be enough fuel to give some signs of life as it is now.  

Have you checked base timing?  

[BrokecaR34]

Bumped master fuel to 25ms for tomorrow morning's testing. Haven't taken a look at current timing yet, is that possible to check with just cranking? Thanks for your time. 

[Adamw]

Yes, you can check timing while cranking.  

[BrokecaR34]

Ah...just randomly did compression test and 1 and 2 showing sub 10psi, might be bent valves , I'd assume too low compression would make it a no start situation 

[BrokecaR34]

Life semi got in the way of this project and I've finally got around to just working on this to get it cranking over and almost starting. 

It starts, and then sputters out, I'm not too sure why? 

Things that have changed since last attempted cranking last year.

map sensor that's calibrated,

AEM x series wide band on Can 2, (unsure if ecu is reading this one)

IAT sensor, 

Auto dream 24 multi tooth cam trigger Hall sensor 

Currently have timing for 15 BDC with offset -80 I believe

 

PC Datalog - 2024-05-22 12;03;47 pm.llgx Nissan R34 GTT G4X Xtreme EDITED.pclx

[Adamw]

Im suspicious of the MAP reading, there is no change in MAP when the engine starts, the throttle is open quite a bit but I thought we would still see some vacuum.  In your first post it says it is wired to AN Volt 1, but in your map it is set to AN Volt 6, was this changed?.  

[BrokecaR34]

Yes, i rewired into an expansion plug instead because I was getting calibration failed errors running through the OEM maf an volt 1 . I was trying to see if applying some throttle would aid in starting since it would add fueling but didn't seem to be the case here.

 I'll check for vacuum leaks and try to see if that's the simple fix here, I ran a few of the vacuum required things to a a vacuum block, the map sensor was one of them. 

[BrokecaR34]

Looks like ive got it roughly sorted out after staring at the log for a bit, was getting way too much fuel.

I adjusted master down to 7, crank enrich from 120 down to 70 at 20c (roughly the temp my garage is at), post start and warm up enrich also lowered by a lot as well and now fairly consistently starts up after cranking, AFR at about 950rpm idle is around 14-15 read off the AEM wideband gauge.

 

[Adamw]

So is the MAP reading correctly now?  It sounds like you still have an issue if you need a master fuel of 7ms for 650cc injectors, a master of 7ms would be more typical for ~ 1200-1600cc injectors.