1g-gte misfiring on first few seconds of startup - common?

[Z2TT]

Thanks,

I'll get onto it tommorow.

[allencr]

...had some carbon buildup on the cap which I cleaned out, ...

There's no such thing. A carbon-graphite center terminal that feeds the rotor & carbon tracks from arcing are all I can recall.
What did you clean?

[celicapain]

Id guess its something to do with the electrics, my gen2 1ggte gz20 always pops and farts for a second or two before settling down and then it runs perfectly-only does it when starting from deads cold though. just my 2 cents

[Z2TT]

Id guess its something to do with the electrics, my gen2 1ggte gz20 always pops and farts for a second or two before settling down and then it runs perfectly-only does it when starting from deads cold though. just my 2 cents

Yep exactly what is happening here.

[celicapain]

when mine does it it actually sounds like it stats on about 3 cylinders, then after a second all the pots light up and its sweet-would this indicate shennagins in the way the batched injectors start up? DOES ANYONE HAVE A GZ20 THATS DOESNT DO THIS?

[Z2TT]

when mine does it it actually sounds like it stats on about 3 cylinders, then after a second all the pots light up and its sweet-would this indicate shennagins in the way the batched injectors start up? DOES ANYONE HAVE A GZ20 THATS DOESNT DO THIS?

Hi, Yep exactly how it sounds like on mine, like it's only running on a few cylinders.

It may be a fuel issue, such as the pressure falling too low in the fuel line when
the car stays off. I think this because before I started the car I took the filter off
while on ignition pushed the AFM flap in for a few seconds to activate the fuel pump
then let go put filter back in and started the car, fired up fine.

Celicapain maybe you can try the same thing?

So that tells me that it could be a one way valve in the fuel pump that is causing
the problem.

[Kedderz]

fuel lines arent being primed.

[LT1986]

fuel lines arent being primed.

second that motion

[jimmmayyy]

Wasn't this already covered?

A Toyota's fuel pump will ONLY start once the COR switches when the ignition is on, thus fuel pressure is low for a short period. Your injectors could be slightly dirty, but other than that i doubt there is a problem. My freshly built 7M with CLEANED injectors also did this.

There's nothing wrong with your car.

[Z2TT]

Replaced the fuel pump today, thinking it would have been a bad check valve, didn't help at all.
Was misfiring real bad today, for 10 seconds, car nearly turned off, some sort of high pitched sucking noise from around the throttle, by the time i went to the engine bay it was gone.

Not sure what it could be now I think it could be a cold start injector leaking so i'll check that out next.

[JZA70R_92]

this happened to my 1Jz also ive cleaned out the ISCV problem solved

[Z2TT]

I've tried cleaning out my ISCV about a month ago or so, didn't help.

I've taken the Cold start injector out, while still connected I bridged connectors +B and FP in the diagnostic port so pressure would build up, the injector doesn't seem to be leaking.

Also I connected the cold start injector to the battery and it sprays well, then disconnected it and let it sit to see if it leaks, no leaks.

So while the gauge was still at cold (right at the bottom), I decided to start the engine, While engine was running, I noticed the cold start injector was not spraying any fuel.

Not sure if the cold start injector only operates when the engine is very cold, or operates all the way until temp reaches halfway. Or only operates at sub zero temperatures like in Japan.

[RA35GT]

It is controlled via the cold start injector time switch.

It essentially only comes on when its fairly cold and is only active while the engine is cranking. (i.e. if it is cold enough to need it, it will only spray when the engine is cranking as its powered from the STA wire).

[Z2TT]

Thanks 7m,

allthough mine didn't spray when cranking, but like you said it has to be probably very cold.
Anyway I just removed it to see if it was leaking by any chance, not a problem.

Took out the spark plugs today, were a bit dark but was probably due to idling on a cold start the day before, will have to take it for a good drive then try again.

When taking the spark plugs out I looked into the cylinders to see if there is any oil or water in them, all of them were dry except for cylinder number three, which had a fairly big pool of oil/petrol mixture. quite thin so i'm suspecting that the third injector is leaking.

I'm wondering, would one flooded cylinder be enough to cause such a harsh idle?

Thanks.

[RA35GT]

Yeah man, according to autoshop101, the cold start only works when the engine temp is under 40deg or 20deg C depending on the engine.

Any amount of running will see temps over this, the only real way to tell is to leave the engine for a while (like overnight) and then test the cold start injector.

Third cylinder with oil/petrol mix is a little worrying.

Check to see if the injectors are leaking (same as how you tested the cold start)

I wouldn't expect one bad cylinder to cause a harsh idle, but it obviously won't be smooth.