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Little Help From The Brainstrust Please..

PRO_32

By PRO_32,
in Engines & Forced Induction

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PRO_32 Proficient

PRO_32

Posted
Posted

The Issue

Car hesitates to start (as if its a high comp NA) then just kicks over trying to start as if its out of fuel (its not)

It will start every now and then and run fine.

Bit Of Background

I was in the process of draining the fuel out of the car via fuel return line on the rail, I didnt like the sound the (newly installed) 044 made as i ran the tank dry so i decided to pour 5l back in and fire her up again to make sure everything was still alright.

At this point car struggled to kick over ( kinda like a dieing battery / really high comp NA motor that struggles to crank over but once the crank starts turning it's fine)

So i thought ok as its jus a track car maybe the batt is a little low on charge, so i charged it (Full), Now it seemed to crank over somewhat easier but still not normal with a slight hesitation to begin with however now it was cranking and trying to fire however just would not kick over.

Seems like its got spark by the way it almost fires up but then not.

So i assumed it could be a fuel delivery issue so i took out the intank pump checked sock for gunk as i Did drain the tank, Cleaned sock and blew out lines with air then the 044 was checked and that seems fine too.

Mind you during all this If i would let the car sit for a little while it would start and run fine and not stall

At this point im thinking maybe its a battery / electrical issue so i took the (larger) battery out of my hilux and there was significantly less hesitation to crank over and it would start time after time, Whereas earlier if i did manage to getr it started it would run fine but turn it off and try to start it again and no go.

Ok so i thought dodgy battery and went and bought a new one (run of the mill. roughly 380cca's) however apon removing the hilux batt and installing the new one similar hesitation it would start but still not consistently, generally once it does start it runs absolutly fine however switch it off and more than likelyit wont sart again till you let it sit for a while.

Sorry if this is a bit long winded.

VITALS:

Car : R32

Engine : Rb25det Series 2

EMS : Nistune (Z32)

AFM : Z32

Fuel : GTR lift pump, inline bosch 044, Siemiens deka 60lbs inj (running E85)

Ignition : splitfire coils , Battery relocated in cabin ( multiple earths in cabin and engine bay)

This is the info i felt was relevant if not let me know.

Whilst i have fairly good mechanical understanding im hopeless with elecronics and i fear thats what this is so anyhelp to put me in the right direction greatly appreciated.

Cheers

Andrew.

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

How did you wire the pump(s)?

What voltage are they both getting?

Why are you running a lift pump to a higher flowing without a surge tank? Sounds like the 044 might be flowing more than the GTR pump is letting through?

(although i remember reading somewhere that sometimes doesn't matter).

How much fuel comes out over 30 seconds if you take off the feed line (from the engine bay) and put it into a bucket?

PRO_32 Proficient

PRO_32

Posted
  • Author
Posted
How did you wire the pump(s)?

Standard trigger feeding 1 relay per pump direct feed from battery for power.

What voltage are they both getting?

Have not checked this yet, (what should it be?) assume you mean at idle?

Why are you running a lift pump to a higher flowing without a surge tank? Sounds like the 044 might be flowing more than the GTR pump is letting through?

(although i remember reading somewhere that sometimes doesn't matter).

It's setup like this cause Im in the process of making an ally cell with built in baffles and sump so no need for surge tank.

I been told the gtr pump is a bit of a machine if not trying to pump against resistance, so with an 044 infront of it there should not be an issue,(at my power levels anyway) and really there hasnt been one until i drained the tank.

How much fuel comes out over 30 seconds if you take off the feed line (from the engine bay) and put it into a bucket?

Gotta say i didnt really measure it like that, however it took probably close to 5 minutes to fill a 20 liter jerry can.

FWIW Last night i noticed it is starting a little more consistently however on the odd occasion it barely wants to turn the crank like the batt is dead or something.

* The battery has just been moved to in the cabin, Is there a possibilty that this could be causing some of my grief?

Cheers

Andrew

tridentt150v Grand Master

tridentt150v

Posted
Posted
FWIW Last night i noticed it is starting a little more consistently however on the odd occasion it barely wants to turn the crank like the batt is dead or something.

* The battery has just been moved to in the cabin, Is there a possibilty that this could be causing some of my grief?

Cheers

Andrew

If your leads, positive lead is big enough and properly crimped /making good contact plus earth strap is in a good location, it won't make any difference where it is.

Try cleaning your terminals and lead fittings.

PRO_32 Proficient

PRO_32

Posted
  • Author
Posted
If your leads, positive lead is big enough and properly crimped /making good contact plus earth strap is in a good location, it won't make any difference where it is.

Try cleaning your terminals and lead fittings.

Battery is brand new ( i think underpowered, rated at 380cca)

Leads are 4g about 3.5m in length, Earthed in boot, in Cabin near battery in engine bay near original battery location and to the engine aswell. Well they are the major earths anyway.

Terminals and lead fittings are all brand new.

I feel like it could be the battery by the way its struggling so hard to turn the crank but why was it not a problem before??

Could it be the starter shitting it self?

cheers

Andrew

Sheriff Wan Proficient

Sheriff Wan

Posted
Posted

Has it always been the case?

Or has this just started to happen? With the z32 ecu running the rb25, your priming time with the pump will go from about 5 seconds from the factory ECU to about 2 seconds with z32/Nistune fitted.

You can try putting a resistor where the fuel temp is in the ECU - should increase priming time. Check the Nistune forums about it

I had the same problem in mine - but it turned out to be low voltage a the fuel pump, so I put it on a direct relay from the battery.

RBceffy25 Rising Star

RBceffy25

Posted
Posted (edited)

I have a very similar problem after pissing of a dodgy walbro (second dodgy walbro i've been through) and installing an 040 with new wiring. Runs at 13.2 volts (give or take) on idle but when engine is being cranked a voltave drop will always occur (down to as low as 10 volts) wich i think may be causin the slight hessitation to kick over.

To combat this i just let my car prime for a few swconds before cranking, kinda like when you wait for the glow plugs to heat up on a diesel.

Funny thing is though the standard pump and the walbro didn't have this problem. But judging by the sound of the various pumps under ther different voltage conditions the bosch really souns like it srtuggles with the voltage drop hence why i let it fully prime. Then starts instantly.

I have cleaned all lines, replaced the fuel tank and filter.(due to rust because of water. the car sat in a yard in japan for bout a year befor i got it)

Hope this helps in some way

Edited by RBceffy25

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