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Hi all

I'm having an issue with my silver top RB20 intermittently not starting properly. If I turn the car on and it's dead cold it starts but if I turn it off straight away and try to start it again it sometimes wont start or even sound like it's close to starting. For it to start again it needs to left for several hours it seems.

The car has been sitting for the last 6 months however prior to that I've had no trouble with it starting in my 5 years of ownership.

At one point when it wasn't starting it ran out of fuel I think (dodgy fuel gauge) as the pump started making a loud noise. I've since filled it up so the fuel in it should all be fresh.

I also had an issue with the car running badly above 2000 rpm and swapped to a new AFM however this hasn't changed the starting issue at all.

If anyone has any suggestions that would be great as I'm at a real loss at what to do :(

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https://www.sau.com.au/forums/topic/453454-rb20det-starting-issues/
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When this happens, try and unplug your water temp sensor on the coolant neck. It's the 2x wire one that goes to the ECU, see if that helps or unplug the AFM

It could be when your car is warm/warmer the cranking enrichment isn't enough to get the motor going.. it could be a mixture of things, dirty/faulty AFM, faulty FPR, dirty injectors, etc.

Changed the spark plugs today, while the car seems to run smoother now it didn't change the starting issue :(

I tired unplugging the wire on the coolant neck while it wasn't starting but that didn't make a difference.

I should mention that I've been turning the car on for max 30 seconds before turning it off and trying to start it so I don't think the problem is really heat related. That said if you leave it for a few hours and come back it will start first time.

How would a go about testing the fuel pump? And could that cause an issue with just start up?

Changed the spark plugs today, while the car seems to run smoother now it didn't change the starting issue :(

I tired unplugging the wire on the coolant neck while it wasn't starting but that didn't make a difference.

I should mention that I've been turning the car on for max 30 seconds before turning it off and trying to start it so I don't think the problem is really heat related. That said if you leave it for a few hours and come back it will start first time.

How would a go about testing the fuel pump? And could that cause an issue with just start up?

did you disconnect the coolant sensor for the ECU or the one for the dash? the ECU one has 2-wires not 1...

(not sure how related this is to you but here goes)

do you have access to a wideband o2?

back in the days when I knew nothing about cars (10+ yrs ago).. I had the same issue with my RB20DET, a mate that was doing engineering at uni suggested I hooked up his wideband. Ended up finding out the car was running lean in general when it was in vacuum, turned out my injectors were all clogged.

As soon as got all the injectors serviced, new o-rings put in the car started easily and idle was back to stoich.

Humour me a little and just try a mates battery

Don't use a jump pack or try jump it off another car

Connect direct to terminals

Ps. Every time you try to start it and it doesn't start your plugs get a bit dirtier and eventually fouled again.

Edited by Sinista32

Just tried a battery out of a car that gets driven every day, had slightly higher cca as well. Result was still the same though.

While it wasn't starting I also took the line off the fuel filter and primed the car and tons of fuel came out. I don't know know if that tells me if the pump is working fine though.

  • 2 weeks later...

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