Jump to content
SAU Community

Recommended Posts

Hello,

I have an RB25DET here that refuses to start. I just finished installing the engine. Before engine removal, it ran perfectly.

What I know:

1) Timing was set correctly

2) It will run on Starting fluid for ~5seconds

3) Cas does work, I rotated it and I can hear injectors clicking

4) As stated above injectors work, Also pulled first 3 coil packs, they all work

5) Fuel pump is working, I can hear it prime and I also pulled the fuel line to make sure fuel is coming out

6) I have a nismo FPR, at this point fuel pressure is unknown

7) Getting error codes for TPS and AFM

8) the Fuel in the Tank is ~1 1/2yrs old

When I go back to troubleshooting, first two things I will check is fuel pressure and compression.

The two main things I'm concerned about are the TPS and AFM. Per JPNZ R33 FSM, there is no reference to the TPS or AFM for starting. However per Z32 Nissan FSM, a AFM will cause a hard start/no start.

Anyone have experience with a bad AFM causing a no start?

I am focusing on fuel pressure but I have a feeling it's fine.

Thank you.

Link to comment
https://www.sau.com.au/forums/topic/41100-rb25-refuses-to-start/
Share on other sites

Hi Jim,

Are you using a stock ECU or aftermarket ?

Are you using a stock AFM or Z32 ?

Have you performed an ECU diagnostic test for error codes ?

I have a Z32 AFM on the RB25 & it won't start with stock ECU due to it's lower voltage output. So i run an A'pexi PowerFC, which allows the user to select different AFM's in the "airflow" menu.

Also are you running a stock fuel pump ? I need to prime my GTR pump (without anti-drain valve) 3 times before I have enough pressure to turn it over. Otherwise it just won't play the game.

As stated above, I would definitely drain the tank & refill. You can buy 100 octane gasoline Stateside, right ?

If everything else is OK, it should at least turn over.

Good luck with it.

Hi Jim,

Are you using a stock ECU or aftermarket ?

Are you using a stock AFM or Z32 ?

Have you performed an ECU diagnostic test for error codes ?

I have a Z32 AFM on the RB25 & it won't start with stock ECU due to it's lower voltage output. So i run an A'pexi PowerFC, which allows the user to select different AFM's in the "airflow" menu.

Also are you running a stock fuel pump ? I need to prime my GTR pump (without anti-drain valve) 3 times before I have enough pressure to turn it over. Otherwise it just won't play the game.

As stated above, I would definitely drain the tank & refill. You can buy 100 octane gasoline Stateside, right ?

If everything else is OK, it should at least turn over.

Good luck with it.

Hello Datto,

Thank you for your reply. The ECU and AFM are factory items. I have performed the ECU diagnostic and it shows codes for AFM and TPS.

I find it interesting your car didn't start with the Z32 AFM. I always thought Any nissan could start without an AFM plugged in, maybe a false signal would cause a no start?. I will look into that.

The pump is a Walbro 255lph, I've tried to start the car multiple times in succession so I don't think priming is the problem.

I will drain the tank and replenish with new fuel.

Thanks :P

make sure u have connect the supply and return fuel lines to the right section of the rail.. We made this simple error on a mates r33 and that was the only drama, doesnt matter if timings out really unless ur talking teeth on the timing belt, we had the engine cam adjuster things out of whack by along way and it started first kick once the fuel lines were coreected.

I wouldn't expect the age of the gasoline to be a problem - after all, it's still basically gasoline.

The other thing to check is the battery voltage while cranking. The ECU requires a minimum of around 7V to spark it into life. If the cranking voltage falls below this level, then there's no ECU to make anything work.

Also, reset the ECU to clear the errors before deciding if there really is an error.

i have had problems with mine but my was more ecu probs then any because the ecu was telling the engine that there was no fuel the ecu was reading it as an error and even cold cranking amps did nothing mine was reading 8.5 v so i fixs thatproblem by taking it to an auto electrician an they fixed it within 4 hrs the computer had to be reset though

Jim do yourself a favour, check my thread in the DIY section with pinouts etc for the AFM.

You will know straight up whether it's the meter or loom/ecu.

Must have been music to your ears to at least hear it turn over !

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • As I said, there's trade offs to jamming EVERYTHING in. Timing, resources etc, being the huge ones. Calling out the factory ECU has nothing to do with it, as it doesn't do any form of fancy boost control. It's all open loop boost control. You mention the Haltech Nexus, that's effectively two separate devices jammed into one box. What you quote about it, is proof for that. So now you've lost flexibility as a product too...   A product designed to do one thing really well, will always beat other products doing multiple things. Also, I wouldn't knock COTS stuff, you'd be surprised how many things are using it, that you're probably totally in love with As for the SpaceX comment that we're working directly with them, it's about the type of stuff we're doing. We're doing design work, and breaking world firsts. If you can't understand that I have real world hands on experience, including in very modern tech, and actually understand this stuff, then to avoid useless debates where you just won't accept fact and experience, from here on, it seems you'd be be happy I (and possibly anyone with knowledge really) not reply to your questions, or input, no matter how much help you could be given to help you, or let you learn. It seems you're happy reading your data sheets, factory service manuals, and only want people to reinforce your thoughts and points of view. 
    • I don't really understand because clearly it's possible. The factory ECU is running on like a 4 MHz 16-bit processor. Modern GDI ECUs have like 200 MHz superscalar cores with floating point units too. The Haltech Nexus has two 240 MHz CPU cores. The Elite 2500 is a single 80 MHz core. Surely 20x the compute means adding some PID boost control logic isn't that complicated. I'm not saying clock speed is everything, but the requirements to add boost control to a port injection 6 cylinder ECU are really not that difficult. More I/O, more interrupt handlers, more working memory, etc isn't that crazy to figure out. SpaceX if anything shows just how far you can get arguably doing things the "wrong" way, ie x86 COTS running C++ on Linux. That is about as far away from the "correct" architecture as it gets for a real time system, but it works anyways. 
    • Holy hell! That is absolutely stunning! Great work!!!
    • It does when you start adding everything else in. But it's not just compute. It's the logic. Getting your timing right (I'm not meaning ignition timing for the engine). Making sure of your memory mappings, seeing your interrupts. Microcontroller devices only have so much capacity. For the most part, you want all those timers and interrupts in use on your engine control, which means you're left with less than ideal methods for timing and management of other control functions.   Let's put it this way, my job is all about building custom hardware, that goes into cars, and integrates with them. We're also waiting on a media confirmation from SpaceX too fora world first we've just completed with them in NZ too. It's not just the little toys I play with. But you know, you can think and believe what you want.
    • I don't think it's a good buy, the trend looks bad     lol.
×
×
  • Create New...