This one's been bugging me for a while. My mum's 306 TD is down on power and pours out black smoke on boost, so much so that it leaves a massive black patch under the exhaust when you rev it.
So far I have looked at:
-Pump settings, I can only assume these are stock as the tamper-proof cap on the boost compensator was still in place and the cap for the max fuel screw looked untouched. It's a Lucas pump.
-Injectors, we ran some injector cleaner through and it didn't seem to make any difference, although this clearly doesn't rule them out as the source of the problem.
-EGR valve, plenty of oily curse word in the inlet manifold so I unplugged the connector for the EGR valve, which I'm led to believe keeps it shut.
-Boost leaks, after doing some reading it seems like black smoke is usually caused by not enough air to burn the amount of fuel entering the engine. I whipped off the top mount intercooler and checked the gasket, which might have been leaking a bit. I used a thin bead of instant gasket which worked on my old d turbo to fix it. While I had the intercooler off, I started the engine and revved it. To my surprise, there was still loads of black smoke. This confuses me because the boost compensator on the injection pump gets its' signal from a point on the intercooler, so without the intercooler the IP shouldn't be chucking in any extra fuel? Also this rules out any restriction on incoming air as the manifold was open to the atmosphere.
Please let me know if I'm wrong about any of this and any suggestions would be great!
Have some pictures of what can be done with an XUD (Darren Lobb):
So far I have looked at:
-Pump settings, I can only assume these are stock as the tamper-proof cap on the boost compensator was still in place and the cap for the max fuel screw looked untouched. It's a Lucas pump.
-Injectors, we ran some injector cleaner through and it didn't seem to make any difference, although this clearly doesn't rule them out as the source of the problem.
-EGR valve, plenty of oily curse word in the inlet manifold so I unplugged the connector for the EGR valve, which I'm led to believe keeps it shut.
-Boost leaks, after doing some reading it seems like black smoke is usually caused by not enough air to burn the amount of fuel entering the engine. I whipped off the top mount intercooler and checked the gasket, which might have been leaking a bit. I used a thin bead of instant gasket which worked on my old d turbo to fix it. While I had the intercooler off, I started the engine and revved it. To my surprise, there was still loads of black smoke. This confuses me because the boost compensator on the injection pump gets its' signal from a point on the intercooler, so without the intercooler the IP shouldn't be chucking in any extra fuel? Also this rules out any restriction on incoming air as the manifold was open to the atmosphere.
Please let me know if I'm wrong about any of this and any suggestions would be great!
Have some pictures of what can be done with an XUD (Darren Lobb):
