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When I bought my truck it had a Isspro Fuel pressure gauge mounted in the left pillar. I installed a Fass150 and Edge Juice with attitude. 2years later, I would like to hook up the Isspro gauge again...it's just sitting there and I think its cool when it works. My question is, whats the best way to make this happen? Cut the line before/after the current one and run a completely separate setup? Will this cause any issues? Below is a pic of my current set up. Thanks for any help!!

I will be editing this continually as I think of more.. Thinking of buying 12v, what do I need to check? Has the Killer Dowel Pin (KDP) been fixed? How is the front end play? When did they last change the bearings? Auto trans -- Does it go into gear well? Is there a lot of slippage in the torque converter? Check and see if the fluid is burnt. Make sure it goes into all gears and locks the torque converter when warm. Manual trans -- Feel for clutch slippage and how well it goes into gears while driving. Ask how many times the 5th gear nut came loose and how they fixed it, be weary if they say they welded it as you wont be able to remove the nut if needed if they did.. Check the dash as long periods in direct sunlight will make them hard and crack. There are 4 bolts holding the AFC housing, one of which should be rounded over (tamper proof) looking the same as the top of a rivet, if they are all regular bolts then you know they have got the tamper-proof one out and messed with the fuel plate (turned it up) and if its an automatic truck, they might be selling it because the more power they got out of it is making the trans very weak. Lastly, encourage them to let you start the truck "cold", as in having not been warmed up prior to your arrival. Any hard starting issue might mean your getting into a money pit, especially if its over 32*F out. What is all the Killer Dowel Pin commotion!? The Killer Dowel Pin (KDP) as its been nicknamed, is an alignment pin behind the timing cover on the front of the engine. It works its way out of position and falls out wrecking havoc. Click here for a writeup on it. I lost 5th gear! This is a common problem on the NV4500. There is a nut on the tail shaft which "holds" 5th gear in place. When the nut works it's way loose, 5th gear slides down the shaft until it loses contact with the splines. It is a very simple fix, though to permanently fix it there are a number of solutions. To get to the nut, you must drain the fluid out, remove the driveshaft, and take the tailshaft housing off. That is all that must come off, only the very end.. Then you will see the nut unscrewed from the threads just flopping on the shaft. Screw it back on and get it as tight as possible. There are updated nuts at the dodge dealership that contain set screws to tighten the nut down even further. People have tack welded them but that does not seem to work, if you don't care about ever taking the shaft out or disassembling the trans, then you can Tig weld it all the way around and that is said to cure it for good. There are also fully splined shafts available that allow 5th gear to slide wherever and always be in contact with the splines (the stock shaft is not fully splined which many believe is the root of the problem). If you put the nut back on and just tightened it there are ways in which you can prevent it from working loose. Avoid lugging the engine in 5th, basically keep the engine above 1500RPM, when you lug it, the nut feels each piston stroke and it hammers the nut off. The second thing is to avoid jerky driving in 5th, as in letting off then stepping on it in a jerking fashion.. this torques the nut off.. Cruise Control and/or Vents only blowing out defrost? This is a very common problem concerning vacuum lines. They will pop out of their rubber connectors or crack causing leaks and then your vents have nothing to run them so they default to defrost and since the cruise works off the vacuum too, it stops working. You will see the little black lines that stem from the vacuum pump that is located behind the power steering pump. They run to the the cruise control unit located under the driver side battery and they also run along the firewall right below where the back of the hood would shut. If only your cruise control is not working, the unit for the control under the battery may have issues and need to be tested. ABS/Brake Light is on? Check the connector on top of the rear differential, check vacuum (94-96'), check the brake switch, also check the ABS sensors. My dome lights and radio don't work! This is something most people overlook because of the labeling on the fuse panel. The "I.O.D." fuse is the one that controls the lights and radio, even though the radio has a separate fuse, this one still kills the radio. This fuse is also the one that has a yellow fuse puller on it, the puller only pulls the fuse out a little ways so that the contacts are not holding the fuse tightly allowing you to get the fuse out with ease, so don't try and rip the fuse puller out of the fuse panel as it is only going to go back maybe 3/16". Why does my temperature gauge fluctuate? Dodge came up with the idea that to be king of the pulling trucks it needed a big radiator.. Without a load, the radiator is way too big for the engine's heat output, causing every opening of the thermostat to drastically cool the engine because of the inrush of cool water. When the thermostat closes, the engine heats back up and then the thermostat opens and cools it off again. This cycle continues until the engine and radiator come to an agreement with temperature and then the range between opening and closing of the thermostat is only about 10-20*F. When pulling a heavy trailer, the radiator is now sized to perfection and the engine temp should stay around 190-205*F. Why does my voltage gauge fluctuate on cold starts? When it is below 60*F ambient temp, you now have to wait for the "wait to start (WTS)" light to go off. This is because the grid heater is heating the intake so that the air is warm enough to start the truck with ease. After the truck starts, it goes into the post-start cycle and will turn the grid heaters on and off to maintain a warmer temperature, this is why your voltage gauge goes up and down since the grid heater draws a lot of power. This post-start cycle will last a while depending on how cold it is. I have seen mine continuing to run up to 5 min past startup, but the longer it runs, the shorter it lets the grid stay on, eventually getting to the point of 1 sec or less then finally just staying off. The other way it shuts off is by going over 20mph. Click here for more info. Is the oil pressure really 40psi all the time? No. The factory oil pressure gauge is merely an indicator showing you have pressure. It is either on or off.. If you hook a real gauge up to it, you will see the pressure go up and down with RPMs. What gauges do I need for a 12V? There is one main/major gauge all diesels need, and that's a Pyrometer/EGT (Exhuast Gas Temperature) gauge. This measures the temperature of your exhaust and gives you an idea of how hard your engine is working and when you need to let off a little. The next gauge most have is a boost gauge, which gives you a measurement of the output of your turbo in psi. This is not as critical gauge as a pyrometer but it does serve some good purposes. Now it is a tossup of whatever other gauges you want. The next level from boost would probably be fuel pressure. It is not that big of problem on 12V trucks but if you want to monitor it and ensure it is running in tip top shape you can get one of them. Not to mention you can tell when your fuel filter is getting clogged. What is the EGT temperature limit? This is a debated topic but the rule of thumb is to not exceed 1050*F. After that is where it gets debatable.. This is what I will say and you can use your own judgement. Aluminum melts at 1220*F, however pistons have oil nozzles under them to constantly keep the piston from getting too hot, but that doesn't mean the piston crown gets cooled that well.. So if you can help it, keep the 1050*F as your limit. If your going up a hill, 1100-1200 might be considered "OK", I would make sure it is followed by a downhill and let off though. The range between 1050* and 1200* is pretty foggy and nobody really knows exactly when the piston will start to melt. However, one thing is for certain, never exceed 1200*F. Your risking everything if you do. What is the normal boost pressure? On a stock truck the turbo is an HX35 or WH1C (94') and the pressure should be between 17-23psi. The 160HP engines will have 17 or so with the 215HP engines having 23. The turbo is only good to 35psi, past that it generates too much heat to be efficient. How much boost pressure will the stock head gasket hold? In stock form it will hold about 40-45psi with some people not having issues up to 50psi. Advancing your timing will lower these limits.. Should I advance my timing and how far can I go? Advancing the timing puts the power curve higher up in the RPM's, so you will have more power in the higher RPM's and less down low. You will gain some mileage too. Keep in mind the more you advance it, the worse it will start. The had gasket is said to be safe up to 16* of timing. Stock is between 12.5 and 13.5. The advanced timing puts more stress on the head gasket so if you are running high boost you may want to reconsider, or do something about the head gasket. How often do I...? Click here for the entire maintenance schedule.

To help those who are new 12V owners, this will give you a rough, possibly detailed idea of how this engine is set up. I made this so people won't have to read for months trying to understand each part and understand the engine, or other brand diesel owners wanting to know how these work so they can help someone else. First we have the specs from the factory of the 1994-1998.5 12 Valve Cummins. There is already a good/complete set of specs for these trucks. 1994-1995/1996-1998 There were hardly any changes from the 1995 to 1996 power differences, mainly just different fueling to provide more power and a slight change in pistons. Year to Year changes can be found here. Here is the part layout of the engine to get familiar with. There is no ECM (Engine Control Module) on the 12V Cummins. The chip on the firewall is a PCM (Powertrain Control Module) and serves only to provide sensory information, it controls nothing about the engine except some timers for the grid heaters and such, the engine does not rely on it at all otherwise. Any error codes from it will concern pointless sensory things which might help but it will tell you nothing about any engine issues. I think there are only 17 possible codes that can be thrown if that gives you an idea.. That list is a full list, most won't apply. If you haven't figured it out thus far, the cummins is an inline 6. The pistons are set to where they have running mates, which are pistons that move together, though on different strokes (one is on compression while the other is on exhaust). Running mates consist of 1/6, 2/5, 3/4. Knowing this will help you understand when adjusting valves since you watch running mates a lot to find TDC. The 12V uses an inline injection pump called the Bosch P7100. It uses 12mm plungers to push fuel much like a "mini" inline 6 engine. Each plunger (piston) is for each individual piston. The plungers are forced upwards by a cam that pushes the plungers up individually based on firing order (153624). Above the plunger is fuel which gets there by means of a little hole (spill port) on the side of the barrel (cylinder wall). As the plunger comes up, fuel is initially pushed back out that hole. The plunger itself eventually covers that hole and because it is sealed, fuel is compressed and after reaching a predetermined pressure, shoots out of the injection pump's delivery valve (high pressure check valve really) and into the injection lines. As line pressure exceeds injector pop pressure, they pop and fuel is injected into the engine. There is a lot more to how it works and how fuel is metered which can be seen here. The injection pump is "turned up" by means of adjusting a fuel plate and AFC settings which allow you several means of fine tuning the power and smoke output. I have articles on this since it is always asked about. Fuel Plate/AFC~Starwheel/Smoke Screw. Fuel is returned from the injectors straight back to the fuel filter, keeping them at lift pump pressures. The only fuel that gets returned is the fuel from the overflow valve in the front of the injection pump. The injection pump's internal pressure (not injection pressure) is regulated at 25-36psi, though up to 45psi is fine. Pressure is regulated with a overflow valve which is just a spring that seats a ball until pressure overcomes the spring and pops the ball out of it's seat, relieving pressure until the ball reseats, thus regulating pressure. The injection pump is driven off the cam gear in the front timing case. The injection pump itself has a tapered shaft that goes into the gear that drives it with just a nut holding the gear on the shaft. The most common way of of timing it is to take the #1 delivery valve out (which takes a special socket, or mess up the teeth with channel locks), and sticking a dial indicator into the hole so you can measure plunger lift. Here is a table showing what lift should be based on CPL number and timing desired. The engine is barred over until proper lift is seen on the dial indicator. The nut holding the gear onto the injection pump is then taken off and the gear is popped off the tapered shaft with a gear puller. The engine is then barred over to absolute TDC since that is what the plunger lifted is based on. The gear will turn but since it is not bolted to the injection pump, the injection pump will remain at the same lift as before. You then tighten the nut on the timing gear back up and confirm you are at TDC and at the lift desired (timing desired). Here is a more detailed writeup of this procedure, remember to refer to the aforementioned table to get lift specs. Fuel is delivered to the injection pump with a mechanical lift pump. It uses the engine cam to push a lobe on the pump which "pumps" fuel into the engine. This is seen as a pulsation of fuel and the pulses get faster with engine RPM since the cam is pumping it faster. It has a manual primer button for bleeding air out of the fuel filter. A fuel heater is right next to the lift pump and consists of a fine mesh filter (bug screen) and the actual heater element. The heater is typically trashed since it never seems to provide any benefit. There are 2 types of fuel filters. The first few years (94'-95' I think) used a spin on fuel filter. The later years (96'-98.5') used an element type fuel filter that goes into a canister. To change the canister version, you look at the yellow lever on the front part of the filter housing, this lever is a valve. Under that valve is a long shaft going to a hose (should be a hose there anyways), put a bucket under that hose as the entire contents of the fuel filter will drain out of that hose. Move the lever towards the engine and it will open the valve and all the fuel will dump. Loosen the nut centered above the fuel filter canister which will lower the canister as it it loosened. The nut will not come out/off, it just spins and is kept in place by some means of connection. At the bottom of the aforementioned valve and maybe off to the side a little is a sensor wire which can be tracked to a connection and disconnected, that is the water in fuel light sensor. Now you can loosen the nut completely and the canister drops down and out. The element pulls right out and a new fuel filter can be installed which should have had 3 new o rings, 1 for the outside lip of the filter (squared edged o ring), 1 for the inside of the filter, and 1 for the inner ring of the canister. Get clean oil on all of these so they will seal correctly. Reinstall and prime the filter using the lift pump primer and by loosening the bleed screw which is a small screw on the top of the filter housing that screws into a larger screw (banjo bolt). Bleed until the air bubbles stop and the fuel is continuous. Loosen slightly injection lines 1, 2, and 3 and crank until it tries to start or fuel comes out of those injection lines, then tighten them back up and start the truck. It will run rough until the air bubbles completely purge out of the system. The fuel shutoff solenoid is the only thing that lets the engine run or stop. It is the only thing controlling it since the engine is entirely mechanical. Aside from the usual glow plugs, the cummins' use grid heaters. This is a coil in the intake manifold that gets hot so all air getting sucked in is heated. How long the grid heaters run and cycle is determined by the IAT (intake air temperature) sensor in the intake manifold. These trucks use a wastegated turbo called the HX35 (WH1C on 94's). They are wastegated in the range of 15-23psi depending on the model of engine. These turbos should not be used for anything over 35psi. They all use 12cm exhaust housings. The wastegate line runs over the top of the engine and tees into the AFC. Being a 12 valve, there are 2 valves per cylinder. They are not hydraulic or anything thus they must be adjusted every 25-50k miles. 15k is better of course. Intake lash is set to 0.01" and the exhaust lash is set at 0.02". Here is a writeup on how to adjust them. The power steering pump is below the injection pump and is driven by the vacuum pump in front of it. The vacuum pump has a gear on the front to mesh with timing gears as it's means of getting powered. The vacuum pump runs a number of things like the HVAC, cruise control and 4wd axle engagement. Leaks will cause the HVAC to default on defrost vents only. The cruise control unit is under the drivers side battery. It works off of vacuum pressure and is a pain to fix once they have gone bad, though cleaning the actuators does help or even fix the issues. RPM sensor is on the front of the engine above the damper. It is a PNP type proximity sensor I believe. The engine itself is direct injected with the injectors off to the side a little. They did not put the injectors directly centered in the bore until the later 1998.5+ 24V's. This means the pistons have a cone that is to one side of it to accommodate the offset injector. That's it for now, let me know if you think something else should be here. I might get some pictures in here.