D40 Starts first time but stalls if restarted.

[Scotty B]

Hello I'm new here and trying to sort out a problem on my Dad's 2007 Navara.
On first start it will start and drive normally, although sounds a little rough, but if it is switched off and then restarted straight away it will start breifly then stall.
If it is let to sit for a minute or two it will start again and drive. I have done a lot of searching on the site and got some ideas but would really appreciate any input before I go buying parts that I may not need.
Cheers

 

[Old.Tony]

Overprime the fuel pump. Not by a small amount.

If the fuel system is sealed and in good condition, you'll be able to squeeze the primer bulb about 4-5 times tops before it gets quite firm (full of fuel). If this is the case, the problem may be elsewhere (see below).

If you can keep squeezing it easily, keep going until you get diesel leaking out. That's the place you have to fix. It might even be the primer bulb itself - you'll know fairly quickly if this is the case!

Other things: it's NOT the turbocharger, because the turbo isn't spinning a lot at idle.

It could be a blocked air path. Don't just check the air filter, check the entire air path to make sure nothing has gotten in to block it (birds, frogs, rats).

Suction control valve - test this by opening the fuel filler cap, start the engine, let it run for a bit, then stop and try to restart. If the problem has gone away, either the SCV is dirty (1 bottle of injector cleaner might do the trick) or it's beyond saving (scoring, pitting) and needs to be replaced. It might still be the SCV even if the fuel cap trick doesn't work.

So, a bottle of injector cleaner is good for the engine anyway, so after checking the fuel lines and the air path I'd throw a can of Liqui Moly Fuel System Treatment in the tank and drive the car.

 

[Scotty B]

Hello Tony, thanks very much for your help.
I'll tell you all the things I have done so far.
The truck has had a P0409 code for quite some time and I had cleared it several times in the last month or so but it kept coming back.
I got the truck off Dad two days a go to see if I can sort it out for him.
I removed the EGR and gave it a clean with some throttle body cleaner and cleared the code.
This didn't make any difference to the stalling problem and eventually the CEL came on and it was showing the P0409 code again.
Today I ran some fuel injector and fuel conditioner through the tank and I cleaned the MAF sensor with some MAF sensor cleaner and after a big drive it started very consistantly without stalling. Although I didn't realize but I had left the plug for the EGR and throttle body diconnected during this time.
I reconnected the two plugs and also replaced the fuel filter. Drove it again and restarted it a few times and it was much better but it did stall a few times. When it stalled the CEL light came on and it was showing the P0409 code again.
The truck does seem to have a lot more power after all this.
I primed the bulb and after about 5 pumps it got very firm.

 

[Old.Tony]

The fuel system seems ok, then!

The error code usually means the EGR valve is in dire need of attention. You can try just spray cleaning it but taking a look in the electrical connections might reveal some oxidisation in there (it's been reported before). Let me find a post by someone who's done a rebuild on one of these for you ... here it is!

https://www.nissan-navara.net/posts/674386/

 

[Scotty B]

Thanks very much for your help Tony

 

[Scotty B]

I followed all the steps in that post. My EGR was fairly clean under the cap. I removed everything and even tested the little motor. Everything is moving freely with no binding. I don't think I left anything out but unfortunately after about 20 minutes of driving and then restarting the truck it threw the code again.

 

[Old.Tony]

That's a little disappointing, the 2007 EGR system is not very intrusive and most failures are basic ones unless the entire gizmo has failed.

Any chance of grabbing an EGR valve off a nearby wrecker? Most cars aren't written off due to a failed EGR!