It all started when I took the truck to Arizona in the summer and it ran hot thru the mountains. I am planning on getting an intercooler but need to fix this problem first. There is approx 50,000 miles on the engine. This new engine has been running good for the last 30,000 miles. Most of all the accessories including the turbo came with the new engine. During the trip all of a sudden I started getting large amounts of black smoke. I replaced the air filter and that seemed to help a little. On the way back the service engine soon light came on and it showed the code 236 - which said turbo performance. During the trip a couple times it started real hard. After getting back home it did not want to start at all. It would turn over and give alot of white/gray smoke and try to run but would not keep going. After turning it over for a long time as it got warmer it would start to keep running but run extremly rough. As soon as it gets warm it runs good. I have replaced the fuel filter. I also ordered new quick heat glow plugs from Kennedy and replaced 6 of the glow plugs but cannot figure out how to replace the last 2 behind the exahust/turbo. Still the engine does not seem to start any better. I had tested the original glow plugs and they seemed ok but figured I had better change them anyway. Also I checked and there was power getting to the glow plugs when the light cycled on the dash. I have since changed the glow plug relay but it still has not made a difference. The batteries seem to be fine and if I have the battery charger hooked up the engine spins over plenty fast but does not seem to make a difference. The glow plug light in the dash cycles on till warm and then cycles less and less. I had thought maybe I was getting a coolant leak, but the coolant level has not gone down at all. It just seems linked to the glow plugs like it is not getting warm enough. Would it still act the same way if the remainder of the 2 glow plugs that were not changed would be bad?


I have an extra Stanadyne pump with the control module that was from a good working engine but I can't see how replacing the PMD would help in this situation or is there something that I am missing? Also it looks like I would need a long needle nose pliers to get the wire off of the PMD in the truck and then I am not sure I would be able to get another wire extension hooked up without removing the intake manifold. I would also need to purchase a heat sink for my extra PMD.


Regarding the black smoke on the trip I thought it might be the waste gate or solenoid but there was good vacuum at the waste gate and when removing the power to the waste gate solenoid it seemed to function properly. It could have been something that was sticking on the trip but is working now. I have not tested the truck under a load since coming back and this starting problem.


Could the turbo somehow be restricting air flow when starting but then work fine when engine is warm?


I also thought maybe the exhaust was creating back pressure, but with it disconnected before the cat it does not make any difference.


Any ideas?

need boost gauge to really monitor turbo performance, wastegate solenoid may be functioning, but if your getting a code 236 it and the vacuum pump are certainly suspect.


How hot did you get the engine? Overheating can really do some damage to your injector nozzles and springs inside, that would make her hard to start, rough idle with white smoke, and black smoke under load.


Get a boost gauge to see whats really going on with your turbo, or if your confident the vacuum pump is good, replace the wastegate solenoid. Pulling a couple of injectors and having them pop tested wouldn't be a bad idea either.

The CTS (coolant tempature sensor) will cause hard starts and make it smoke. It's the one on the aluminum water passage in front of the IP. It should give an Omh reading coresponding to engine temp on the dash(a different sensor).

regarding the 236 code.. after we cleared the code it never came back. I will have to get a boost guage. Would a bad or erratic vacuum pump alone cause the hard starts?


It overheated on me thru one of the passes and after I stopped the temp kept going up. The fan clutch was not operating right. I still need to do something about that.


It is very possible the injector nozzles got too hot. Along with everything else in the engine. would it cause less fuel or too much fuel or erratic fuel? Too much fuel and not enough air I can understand all the smoke. with not enough fuel being injected would that still create the white smoke? Or would it be erratic between the cylinders and make some not come to full compression?


I looked at the Coolant Temp Sensor yesterday and was thinking about it. I will have to try that also. Why would that cause the hard starts?


Thanks for your suggestions and help.

Injectors are know to cabonize when overheated and spray a stream instead of atomizing the fuel. It runs fine hot because the fuel burns easier. When the engine's cold it's hard to get ignition.


CPS reading/value is part of the PCM computations and when it's a bad connection it advances the engine and increases the fuel.

Vacuum pump, turbo, wastegate solenoid all have nothing to do with startability. If the 236 Code and the smoke have not returned, then I wouldnt' worry about it.


Heat weakens the springs, lowering the opening pressure and ruin the seat of the nozzle which makes it unable to atomize fuel. Very high heat can cause the injector to streak or even hang open causing white smoke, miss and knock.


Worst case scenario, you got it REALLY hot, aneeled the piston rings and lost compression...lets hope not.Edited by: Texas Diesel Guy

code po236 is the turbo boost range sensor. my ses light would come and go when i was having problems with my truck. instead of fixing a system that is prone to fail again, i installed the turbomaster and removed the vaccum pump and havent had a problem or code since.

I was a big supporter of the OEM setup, but now that I've replaced the WG solenoid, WG actuator, repaired several vacuum lines, and now my Vacuum pump has taken a dive on me I'm undecided which way to go.

A TM is lots cheaper than a vac pump, I've had good success with mine