TRD Aurion coughs on first morning start

[Platypus]

Its been doing this on and off for a while - the first start, in the morning it will cough once or twice before it starts.

Then it's fine all day for any number of starts.

I have taken it in to Toyota twice to get diagnosed, but there are no codes, and they don't get the coughing issue even left for 2 days - and that's strange.

I have asked Grand Motors at Southport but they had never heard of the issue happening.

Has anyone had this issue?

[Cbr600]

What is the fuel pressure?

What are the plugs telling you ?

[Platypus]

Toyota checked fuel pressure - reported it was fine.

Plugs ok

No diagnostics on the computer.

Remember it only does this occasionally and only once at the first start of the day.

There is only one thing left to do - remove and clean the injectors.

The injector service tech looked up the injector for this car and said they do give trouble - well maybe some do!

I recently used a mobile "chem-tune" but the next morning the car still coughed on start.

Next is to use a mobile Injector cleaning tech( who doesn't remove the injectors - I will need to get that done) - remove the injectors, check spray pattern, ultrasonic clean and replace Oring seals.

Has anyone done this - is it necessary to remove the supercharger?

I have asked my local Toyota service manager - but he could not find any information on how to do this - so quite pointless asking Toyota to do the job.

[Cbr600]

I haven't worked for toyota in 10 years . Back in the day we used to use a fortron oncar injection cleaner. We disconnected the fuel pump. Clamped off the return line. And connected the kit to the fuel line. It's only good for keeping the system clean.

I'd even consider carbon build up on the injectors?if so get a spray bottle with water, remove the air filter give the car some big revs and spray some water in- not a heap or you'll damage the engine.

[Cbr600]

They need to connect a fuel gauge.measure the fuel pressure running. turn car off measure it again. Let sit overnight then check the pressure again. Start and if it misfires check the pressure, do the same for the next morning. Before starting it clamp off the return line then start... Checking fuel pressure and the misfire

[Platypus]

Thanks for those ideas.

I just contacted Toyota again and the service manager said that they put a fuel pressure gauge in the fuel line. I left it there for two days.

They started it after the first day and no coughing. The fuel pressure was still up within spec.

The same the second day and no coughing.

The TRD Aurion has no fuel return line.

A week ago I used "LubeMobile" who did an on car clean of injectors and overhead gear and pistons.

They use "Chem Tune" - it's about a 500ml can which is mixed with fuel to 50% then poured into a steel pressure vessel with a pressure gauge - the fuel line is disconnected and this pressure vessel supplies the fuel - they hang this from the bonnet clip, inject 30psi air and start the engine until it runs out.

The chem tune injection line has a sintered metal end on the 2mm SS transfer line.

This procedure is repeated with this capillary inserted under the throttle body boot so the fuel mix now injects - at 15psi this time- into the intake manifold via the supercharger. Revs are kept up at about 2000rpm during this part as the mixture is very rich.

Of course the fuel pump power is disconnected - either pull the plug, under the cover plate under the back seat, or easier, pull the EFI2 15A fuse (blue one) - I checked the circuit schematic at Toyota for this.

I have done a lot of homework on this problem and the injector guys all say that these injectors are a problem and can carbon up - the removal, spray pattern check to find the culprit then ultrasonic clean and Oring replacement is the only way to fix this for sure.

I will need to find out if the supercharger needs to be removed - but it looks as if the fuel rail line can be loosened and the injector unclipped - the injectors need to go down straight as they have a long nozzle.

The question right now is - do we need to remove the supercharger?