The last episode put my truck on the back of a flat bed for a ride home. When they die stall , you loose your ability to control your vehicle with the loss of steering and braking for the most part. The pressure should be below 12 psi. So the problem is a shot injector pump. Housing pressure partially controls injection timing. Be careful when you remove it so you don't loose the coil spring that sits in the hole. Supposedly, shifting the optical sensor 1mm will achieve power gains.
I lost all power steering and brakes. The vehicle was not repaired. Engine stopped last Monday and will not restart. More pressure retards timing, and less pressure advances injection timing. As for replacement - I'd consider having a Stanadyne shop do the work. Could not or would not fix the problem. When the timing signal is 'missing' the system will advance the timing to the max, hence the engine will get very noisy.
After stalling, the vehicle was not easily restarted. Not starting, stalling, hard starting, and hesitation are injection pump symptoms. I have seen around 4 hummers with this problem in the last year 2004. Injection Pump Housing Pressure If the fuel return function in the injection pump becomes restricted and the internal pump housing pressure rises above the normal 10-12 psi, the injection timing will be affected. The scan from the tech 2 came back with the codes P0251 and P1216 both indicating a bad injector pump. The contact stated that the vehicle was previously repaired with the replacement of the fuel sending unit, fuel filter and the turbo charger waste gate solenoid to no avail. Lookup Diesel in the Yellow pages to find a local dealer.
All along we've done research and had it rediagnosed by a professional diesel mechanic, so we knew to tell our dealer automall in brattleboro Vermont to replace the pump mounted driver pmd sometimes called a fuel solenoid driver fsd. A pump driver cooler pdc can mount on the firewall not the engine to move the pmd away from the heat. Stanadyne says they bench check them with a 12 volt power supply to check actuation. If everything is working properly, the actual injector timing should closely resemble the desired injection timing. This has occurred on interstate highways, in the middle of busy high speed intersections.
To prove whether it is the injector swap it with the next one and see if the problem follows the injector. It is extremely dangerous when these vehicles die because of the pump problem. First, check that the engine is getting uncontaminated fuel and there is no water in the system. A constant air leak in the injection system will affect combustion efficiency and can allow white smoke generation for a longer period of time. The vehicle was inspected by a dealer who determined the fuel pump needed to be replaced again. Check the injection timing first for an excessive white smoke problem. The truck shut off without warning a tractor trailer was behind us thank god he was paying attention and no one was hurt.
I cracked loosened the fuel injector line to reduce fuel pressure and the knock goes away. The rough starts are occurring whether the engine is warm or cold, block heater used or not. Injection Pump and Injectors An injection pump with stuck or defective advance mechanisms can cause the engine to smoke abnormally. Do a compression test on cylinder 1 and on 3. The engine will most likely run a little rough as well as exhibit lower power than normal.
Several report having almost had serious accidents like I had two days ago. You can use a shop drop light and a mirror to see where the leak is. It is an electrically controlled valve that shuts off the flow of fuel to the injection pump. There are several ways that water is blocked, so it is unlikely this will happen. Go to the time set function, with warm engine. My Hummer has only 51,000 miles on which I do not think is a lot for this kind of diesel engine, so I called Stanadyne the manufacturer of the injector pump. This video is about replacing the 6.
A higher reading would indicate a restricted fuel return line. Keep it clean and don't let dirt get into the pump. What happens is that the injection pump will supply more fuel than is necessary to the injector. This injection pump can be used in naturally aspirated and turbo charged applications. The vehicle was inspected by a dealer who determined the fuel injector pump needed to be replaced.