Patrol gq 1990 power loss

[MattZ]

Hi guys,
I have a patrol gq 1990 with a rb30. When I’m driving in the morning after 10 mins it starts to lose power. I have to stop and start again and the idles are a bit rough. But this isn’t happening when I’m driving back in the evening.
Any idea which problem could be?
Cheers

[mihit]

Auto/Manual? Carby/Injected? Service history?
What have you tried already to diagnose and/or fix it?

[MattZ]

Auto/Manual? Carby/Injected? Service history?
What have you tried already to diagnose and/or fix it?

Manual, not sure if carby or injected.
The fuel pump has been changed 4000 kms ago.
I tried to change the fuel filter, but it’s still having the same problem.
Do you think could be the cold weather?

[mudnut]

Hi guys,
I have a patrol gq 1990 with a rb30. When I’m driving in the morning after 10 mins it starts to lose power. I have to stop and start again and the idles are a bit rough. But this isn’t happening when I’m driving back in the evening.
Any idea which problem could be?
Cheers

Welcome to the forum. a carby is a unit sitting atop the inlet manifold. It just lets engine vacuum suck a metered amount of fuel into the engine. Fuel injection is done by installing a fuel rail and individual injectors for each cylinder. My RB30 Carby used to do exactly what yours did. There are two main culprits.

The carbies are fitted with an auto choke. this just shuts the throat to the carby, which causes more fuel to be sucked in when cold. To apply the choke, just press on the accelerator once, before starting the engine. As the engine warms up, after a few min when in nuetral gear, just give the accelerator a quick dab. This should release the choke.

The choke break diaphragm. This little unit which sits on the top rear side of the carby is there to pull the choke off when the temperature is raised enough for the engine to run with out extra fuel. Sometimes the diaphragm is split or has a hole, and cannot release the choke, which floods the engine with fuel. You will see black smoke from the exhaust as the engine dies.

The second culprit is the carby linkages and the second carby barrel butterfly getting stuck.

Here is more info on the RB30. http://www.nissanpatrol.com.au/forum...-Helpful-Hints

[MattZ]

Welcome to the forum. a carby is a unit sitting atop the inlet manifold. It just lets engine vacuum suck a metered amount of fuel into the engine. Fuel injection is done by installing a fuel rail and individual injectors for each cylinder. My RB30 Carby used to do exactly what yours did. There are two main culprits.

The carbies are fitted with an auto choke. this just shuts the throat to the carby, which causes more fuel to be sucked in when cold. To apply the choke, just press on the accelerator once, before starting the engine. As the engine warms up, after a few min when in nuetral gear, just give the accelerator a quick dab. This should release the choke.

The choke break diaphragm. This little unit which sits on the top rear side of the carby is there to pull the choke off when the temperature is raised enough for the engine to run with out extra fuel. Sometimes the diaphragm is split or has a hole, and cannot release the choke, which floods the engine with fuel. You will see black smoke from the exhaust as the engine dies.

The second culprit is the carby linkages and the second carby barrel butterfly getting stuck.

Here is more info on the RB30. http://www.nissanpatrol.com.au/forum...-Helpful-Hints

I noticed that it consumes an higher amount of fuel when this happens.
I’ll try to have a look to the choke, thanks for the answer!

[mihit]

^ This guy knows his RB30s. So definitely follow his advice.
I usually deal with, ahem, real engines.

[MattZ]

I noticed that it’s consuming more fuel when this happens.
I’ll have a look, thanks for the answer!

[stevenbaker658@gmail.com]

I’ve got the exact same problem MattZ is having I’ve got a 1990 Gq manual with carby it’s only ever a pain in the ass on these cold mornings fuel economys terrible only when cold too