I have a 2007 d40 and some mornings on initial start up it will enter some type of limp mode or over fuelling and won't rev past 2.5rpm, zero power up any hill and if you try it give it some, just crazy amount of black soot and nothing. But let is warm up about 2 -3 kms and it goes back to normal. This only use to happen when 4wding, you'd stall it while driving (engine completely warm), it would do the same thing. Any thoughts?
D40 Enters a Sort of Limp Mode When Starting Sometimes
- Thread starter tane
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It's an odd problem. I wonder if the glow plugs are working properly? There might also be an issue with the turbocharger control (or the turbocharger itself). It might just be a failing EGR valve. It's hard to say until we get some more info about the engine, but there are a few things you can look at to start with.
Check the small hoses that connect to the turbocharger, looking for cracking or hardness. Either will allow vacuum to leak and reduce control of the turbocharger. The round gold part on the top of the turbo is called an actuator, it has an arm underneath that adjusts the vanes inside. When idling, this arm may or may not move much, but when revved a little, it should move a bit. If it doesn't (and the hoses are good), then you might have a faulty Boost Control Solenoid (BCS). These don't usually "come good" with heat, but there's always a first time eh?
A 2007 model car won't have an EGR flow detector so you can pop the gasket out of the EGR tube where it connects to the EGR valve and make a copy of the gasket but without the large central hole then install both back in the joint with some sensor-safe gasket cement. This will block the EGR and resolve the EGR valve issue if that's faulty.
Check the small hoses that connect to the turbocharger, looking for cracking or hardness. Either will allow vacuum to leak and reduce control of the turbocharger. The round gold part on the top of the turbo is called an actuator, it has an arm underneath that adjusts the vanes inside. When idling, this arm may or may not move much, but when revved a little, it should move a bit. If it doesn't (and the hoses are good), then you might have a faulty Boost Control Solenoid (BCS). These don't usually "come good" with heat, but there's always a first time eh?
A 2007 model car won't have an EGR flow detector so you can pop the gasket out of the EGR tube where it connects to the EGR valve and make a copy of the gasket but without the large central hole then install both back in the joint with some sensor-safe gasket cement. This will block the EGR and resolve the EGR valve issue if that's faulty.
thanks so much for the reply, just to clear some information i missed. The EGR is already blocked off so it won't be that. I have check all the vacuum hose to the turbo and controller and they look in good condition, but might change them to be save, but it might boost controller is being stupid and not working properly. It feels to me like (might be wrong) the ecu is over fuelling the motor big time, just doesn't make sense. I will change the boost controller first and let you know what happens.
Just to make it clear (for anyone reading this): diesels work based on a certain amount of fuel and a certain amount of air. At the correct ratio, you can't see any smoke from combustion.
Increasing the amount of fuel (without increasing the air) results in too much fuel for the amount of air present, so the fuel can't burn completely. This exact same result comes from reducing the amount of air, because you're doing the same thing to the ratio of fuel to air.
So, lots of black smoke doesn't necessarily mean your injectors are oversupplying. It's also a lack of air.
And just to throw a spanner in the works: "not enough air" could also mean too much exhaust via the EGR valve.
These are the things we have to try and figure out when trying to diagnose - by text - problems with cars emitting smoke. There are numerous reasons why air might be reduced, or fuel increased. There are quite a few clever people who frequent this forum who have a lot of experience with these but sometimes diagnosis can take time, especially if we're not in the same time zone as you!
Which reminds me (for those reading this, anyway) - it's a great help if you put your country in your location on your profile, because some countries do things differently with these cars!
Increasing the amount of fuel (without increasing the air) results in too much fuel for the amount of air present, so the fuel can't burn completely. This exact same result comes from reducing the amount of air, because you're doing the same thing to the ratio of fuel to air.
So, lots of black smoke doesn't necessarily mean your injectors are oversupplying. It's also a lack of air.
And just to throw a spanner in the works: "not enough air" could also mean too much exhaust via the EGR valve.
These are the things we have to try and figure out when trying to diagnose - by text - problems with cars emitting smoke. There are numerous reasons why air might be reduced, or fuel increased. There are quite a few clever people who frequent this forum who have a lot of experience with these but sometimes diagnosis can take time, especially if we're not in the same time zone as you!
Which reminds me (for those reading this, anyway) - it's a great help if you put your country in your location on your profile, because some countries do things differently with these cars!
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