GRUSS

Hey guys, long time reader, first time poster.
I'm usually pretty good with fault finding both mechanical and electrical on my car, however, this has me at my wits end and I'm outta ideas

So as the title states.
Car will start when cold, no worries. However if I say, drive to the shops and turn the car it becomes very difficult to start if at all. If I try to start it within 10 minutes of turning it off it will turn over slowly and sometimes fire, sometimes not. Usually under 10 minutes I can get it to eventually kick then off we go. Anything over 10 minutes it will just turn over slowly and not fire.

If the car isn't starting I will usually ask someone nearby for a jump and as soon as the other battery is connected it will tuen over faster and fire first time no worries.

I believe this could be a voltage drop issue causing the ECU to not fire the injectors because sometimes as soon as the starter motor spins up a little faster so there is less load it's like the ECU gets the voltage it needs and will then fire the injectors.

The usual suspects of the alternator and starter motor are both new units. The starter motor in particular is only maybe 500km old. Had the batter load tested at battery world and they said it's all good.

This all just started happening out of no where, the only events that happened nearby to this is when I got the car tuned on MAFless with flex fuel, 1300s and 460 pump.

So I'm out of ideas for what to try next and it's VERY frustrating as I can't take the car anywhere for fear of it not starting and needing a jump. As soon as there is another battery connected to the terminals in the engine bay it fires up straight away no problem.

Few details on my car if it makes a difference..
MAFless tune on factory ECU
FLEX fuel (this issue happens on any mixture of fuel. Even when it's mostly 98)
ID 1300s
460 pump with standard wiring
battery relocated to the boot

TIA guys, hopefully I can fix this soon!

rob.saj

A friend of mine is having the same problem, began happening in the last few days, still not too sure what it is.
Ruled out the battery and alternator aswell, thinking is either fuel or spark related.


This is on a bone stock car too.


Anyone else had this problem?

GRUSS

My next thing is to try a bigger battery with a higher CCA and see if that fixes the issue. Just for arguments sake.

Once the car is running there's no issue. So pretty safe to rule out fuel or spark.
UNLESS the combination of bigger injectors and fuel pump is causing more current draw and something can't cope?