bose

iTrader: (5)

It's actually an evo 8/4G63 that keeps blowing up, I think he's cursed honestly haha.

I agree 9K, I'm currently boosted on a remaned engine I'm going to give this hell until it goes and do a solid rebuild and then swap for another power plant.

I bet the swap/Frankenstein section fills up with build threads in the next few years.

9krpmrx8

iTrader: (46)

Okay, so I all of teh sudden starting having long cranking times. I have a new battery, brand new series II starter, and I just compression tested last weekend and all is good.

Well, I think I norrowed it down. I though previously when I turned teh key to the on position that my fuel pressure went straight to 60psi. So to confirm this I asked Paimon and Houstonrx8er to confirm since they both have fuel pressure gauges. well both of them confirmed that pressure does build instantly when the key is turned to the on position.

Paimon made a video:


And here is a video of mine:


I have a BHR fuel pump assembly that was purchased about 16,000 miles ago. So should I just replace the pump itself or do you guys think this issues could be something in the assembly or something else? I have access to the pump from an 09' R3, I may just swap that in. I have no fuel pressure issues while driving, it stays at 60psi, even under boost and AFR's are fine.

Carbon8

iTrader: (4)

IRCC the S2 pumps are great, if you already have one I would just swap it in.

Also to confirm, I have a fuel pressure gauge as well and mine is the same as Paimon and Houstonrx8er. Im at 60PSI before I even crank, although mine reads 59 PSI but who's counting

ShellDude

iTrader: (12)

58-60 ish here too

9krpmrx8

iTrader: (46)

It's weird, I am guessing when you turn the key it primes the pump but mine is not building pressure until I start cranking.

paimon.soror

iTrader: (15)

A common source of slow priming is either an air leak, or a clogged up fuel filter. The latter is somewhat rare, but not sure if you did anything to your fuel system recently that might need a look over.

shadycrew31

iTrader: (6)

Seems more like the fuel pump isn't getting the proper control signal saying to go into supa dupa mode.

Possible fuel pump resistor issue?

9krpmrx8

iTrader: (46)

Yeah I was thinking an air leak as well. The blue vacuum fuel line seems fine but I guess it would not hurt to pull the UIM. Not sure how the resistor works, but I was thinking something electrical as well. Of course swapping pumps would tell me too, I have a few stock pumps laying around.

Carbon8

iTrader: (4)

This actually makes much more sense, why didn't we come up with it first

FazdaRX_8

iTrader: (1)

what about that HI-LO fuel pressure resister thing by the air pump in the engine bay, maybe there is some fault with it?

FazdaRX_8

iTrader: (1)

Too, Slow.....

9krpmrx8

iTrader: (46)

Hmmmm, I reckon I need to properly troubleshoot this issue. I guess I will OHM out the resistor when I get home.

Carbon8

iTrader: (4)

Im sure with the abundance of 8's located in your immediate location the simple swap and check method is in your foreseeable future.

9krpmrx8

iTrader: (46)

FSM indicates a possible pressure regulator malfunction but it cannot be inspected or repaired, new pump time.

blackenedwings

New pump is WAY better than a new motor.

Carbon8

iTrader: (4)

New motors are more fun

9krpmrx8

iTrader: (46)

, so true.

Brettus

iTrader: (2)

Interested to hear outcome as I think I've been having a similar issue but don't have the fuel pressure gauge installed (yet).
Noticed my Walbro pump was sounding a bit .............. rattly . Cranking times increased around the same time . Now pump has gone back to its usual whirring sound but cranking is still longer than it should be .

Have taken to letting the pump run until it shuts off then cranking - which seems to help.

9krpmrx8

iTrader: (46)

Yeah it only does this after sitting for a bit. If I start it, shut down, and then start it again the pressure is built up so it fires right back up without delay. It's only when it sits for a while that I get the long cranking times. I will investigate after work.

Edit: never mind, duh.

https://www.rx8club.com/series-i-do-...ries-i-230326/

9krpmrx8

iTrader: (46)

Meh, f!@k that, that looks like a hassle. Now to look into Aermotive.

shadycrew31

iTrader: (6)

Actually now that I think about it... That resistor might be getting overheated causing it to go poo poo.

I have mine sitting in the garage, It will literally take 5 seconds to plug mine up just to test and see if its the resistor...

Stop by after work man.

9krpmrx8

iTrader: (46)

Good idear. But It only does it after sitting a while, I may just have to pick it up, install it, and then see tomorrow morning what gives.

shadycrew31

iTrader: (6)

But your fuel pressure is always at 10 psi in the "on" position right? Even if its hot, cold, Christmas, brunch, new years, Kwanza?

9krpmrx8

iTrader: (46)

No, only if the car has been sitting. If not the pressure stays up and it restarts fine.

shadycrew31

iTrader: (6)

Yea I am really leaning towards the resistor... Curious to find out!