Sol-d fuel solenoid driver

Change preferences. Solenoid driver Probably one of best known methods of converting electrical energy into mechanical energy is the solenoid. Block diagram. AN - Driving solenoids in automotive applications There are a wide variety of solenoid drive circuit topologies. Starting off - the Stanadyne DS4 injector pump as an overall unit, including the PMD has gone through over 20 revisions since it's introduction.

Many of the improvements are internal, but 2 of the improvements are involving the PMD itself. Introduced in , the pretty accurate rumor mill out of Detroit has Stanadyne losing the argument with GM about the placement of the DS-4 injector pump, which we all know is in the middle of the "V" between the valve covers.

This unfortunately places the injector pump electronics in the middle of a ton of heat. The heat is balanced in theory by the fact that the PMD is being cooled by the diesel fuel itself running through the pump. In theory, this is true, in actuality - the damage is being caused while the engine is OFF, not while it's running.

Reports have shown that the pump itself will peak in temps around degrees F. When the truck is off, the heat soak will push the temps to anywhere from to degrees, depending on ambient temps of the season and location.

The reason why the unit fails from reports via Stanadyne dealers and Diesel Forums is basically the transistors themselves will lose connection due to the epoxy compound used to seal the unit together weakening, eventually allowing the transistors to literally work their way loose. Add to the issue that you need a good and clean ground the case itself provides some of the grounding! Getting technical, it seems from what I can tell by looking at a destroyed PMD that the unit is basically a huge set of transistors one of them I believe is a Darlington in which one triggers the other to fire an electrical pulse, and will vary the pulse based on the input from the PCM engine computer.

I'm not crazy about the design myself. The dual layer PCB has a tendency to delaminate, and the board design when looking at the reverse engineered designed diagram should have been far more robust for a diesel workhorse engine. Getting to the specific PMD question you're posing - what we are seeing here is classic failure of first and second generation PMD's.

Because AM General didn't put in the 6. Add the fact that many Hummer's aren't daily drivers mine is! GM had such a problem with PMD's and early generation injector pumps that they had to warranty the units for , miles. According to Stanadyne rebuilders there have been 3 variants of PMD's, with the latest one being either an improvement or a problem, depending on who you talk to.

PMD's with a on it's case are the worst. This is the first generation and the most prone to fail. It seems that this electronic module overheats and goes bad. The engine will probably start when it's cold and have a hard time as it gets hot. If the engine doesn't start It was suggested that you pour some water on the left side of the injection pump to cool off the PMD. PMD's with a are second generation, and are ironically preferred by some Stanadyne tech's because they will either work, or won't work, like "a light bulb" according to one tech.

A Stanadyne tech in Ontario, Canada note the location - definitely a low risk of heat soak in that area! The third generation actually has gone through some mini-revisions of it's own. This unit was designed to allow you to "limp home" yeah, right by operating for a short while, then fail.

The latest variants of the third generation are the most sought after versions. The latest versions sold by us are the most dependable.

You have to remove the injection pump to remove and replace the PMD although I've heard from some mechanics that they have removed them by using a very short torx bit wrench below. They may have ground one down to fit in the narrow space. One owner was able to remove the PMD with a heavy duty "putty knife" the kind where the blade goes through the entire handle and you can hit it with a hammer I sheared off the thin torx screws attaching it to the pump and remounted the new one to a cooler and reused the resistor that was embedded in the socket.

Owners have told me that the best way to go is to get a unit that has a remote mounted heat sink off and away from the hot engine. If you get a new PMD you will need a new calibration resistor unless you take the old one out of the defective pmd.

The resistor describes the pump to the electronic control system. If you get a complete master cooler kit a new resistor will be included. Any pump will run with any resistor. The resistor is a way that stanadyne can insure that all the pumps leaving the factory will put out the same amount of fuel. When GM says the engine has hp it will mean that each new engine will in fact be to spec. The 5 resistor is considered the "average". The resistor is only used when the control computer forgets what the value is, like after the batteries are disconnected.

You can get the computer to see the new resistor by initiating a TDC Learn with a tech 2 scan tool. The computer will check the resistor value on it's own every 50 startups.

The resistors are keyed for correct installation. Notice the curved top and the alignment tab in the socket. The resistor number faces up.

You can see the number printed on them by looking at them. Use a dental mirror and a flashlight. To remove them, use small snap ring pliers. There are two small holes in it that you can hook the pins into to pull it out. I was able to do this without removing the PMD from the pump.

The PMD module contains a pair of high-power driver transistors that generate heat during normal operation. Knowing the PMD module drives the fuel solenoid approximately 7, times a minute at just rpm brings the operational requirements into clearer focus. These driver modules are worked very hard and generate significant levels of heat. Use more throttle, and the fuel solenoid is driven harder and for a longer duration.

This means the PMD will generate even more heat under high load or high-speed conditions. Tests have shown that even a low fuel level in the tank or a non operating electric fuel-lift pump will cause the PMD to work harder and generate more heat Add a high ambient temperature or a dry, thin fuel , such as that found in the Southwestern US during the summer, and you begin to see why these heat induced PMD failures occur more frequently in those areas of the country.

Getting a p will generally give you something else paired with it. Best case - you dump a bunch of Stanadyne Fuel System additive in for a few weeks, clear the code out with the OBDII tool, and you'll never get it again.

My Hummer has only 51, 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. After I read them the codes they explained that the optical sensor in the pump had failed. They gave me the model number of the pump used in all diesel hummers DS These solenoid get pricey, so instead pilot operated solenoid valves are used. Pilot Operated- Pilot operated valves use the pressure of the fluid to close and seal the orifice. This allows for a larger orifice without a larger solenoid.

The second type of classification is based on the resting state of the valve: Normally Closed N. This is the more common of the valves. Normally Open N. We offer a variety of solenoid valves of different sizes, materials, and acting mechanisms. This is the U. This is an integration of 8 pneumatic solenoid valves and a manifold base. Standard Key Features: powertrain control, pre-driver, signal conditioning and switch monitoring. Target Applications Powertrain and Vehicle Dynamics.

Functional Safety and Automotive Security. Body and Comfort.