SSDiesel Supply^TM - Frequently Asked Questions
Diesel innovations

• Q: Do I have to use a calibration resistor in my 6.5?
• A: If you have a 94+ 6.5 with electronic fuel injection, you must use a resistor. Stock is a #5 plus/minus one. With no resistor in place, the computer will default to a #1 setting to keep running, but performance and mileage will suffer.
• Q: If I change to a #9 resistor, will I have to recalibrate my injection pump with a scanner?
• A: No. Changing the resistor will not affect any of the computer settings, just alter the fuel rate.
• Q: Someone told me that if I change the resistor value, the PCM will not recognize the change without using a scanner to reset everything. Is this true?
• A: Only 1/2 true. To prompt an "instant" recognition of the new resistor, a "TDC learn" procedure will need to be initiated with a Tech 2 scanner. BUT, the PCM will automatically check resistor value every 50th keystart of the engine, and make the necessary adjustments in fuel rate.
• Q: What is the purpose of the calibration resistor?
• A: The resistor fine tunes the injection pump much like the adjusting screw did on older non-electronic pumps. The resistors are available in values 1-9. Stock being a #5. Diesel enthusiasts have known since 1994 that the #9 increases fuel rate by 6% over the stock #5 and everyone knows that with diesels, more fuel equals more hp. The beauty of the #9 is that due to increased operating efficiencies, it will also usually produce better mileage too, if driven sensibly.
• Q: My truck is experiencing stalling and once in a while it won't start at all. I suspect the PMD is bad. Will your FSD Heat-Sync^TM solve my problem?
• A: As long as you install it with a fresh PMD, as in my "kit" version, yes it will. A cooler alone will not fix an already toasted PMD, just prevent it from happening again. You will need a new PMD.
• Q: How can I be certain my stalling problem is the PMD and not the injection pump?
• A: The PMD itself does not have a failure (DTC) code. If no "check engine" light is coming on and you are exhibiting the symptoms outlined on our FSD Heat-Sync^TM products page, it is better then 99.9% a failing PMD. But if the light is coming on, we will need to read those stored codes to make a final assessment.
• Q: What makes your FSD Heat-Sync^TM better then the competitions?
• A: Read my list of advantages on this website.
• Q: Do I need an extension harness to install your FSD Heat-Sync^TM?
• A: No. Our location does not need an extension. The harness fits perfectly with no stress or strain on the wires. We only offer an extension ssd-9908 for the rare occasion when the stock harness is tangled around an injection tube and the installer does not have the patience to untangle.
• Q: Will your Cooling Upgrade Kit and/or Fan Upgrade Kit fit my 6.2?
• A: Unless it has a serpentine belt drive, it will not. Early v-belt drive 6.2’s spin the water pump CW rotation, serpentine belt drive spins CCW, and the pump and fan will not work properly.
• Q: My 6.5 sputters on hard acceleration, and sometimes is hard starting overnight. Could it be the PMD failing?
• A: It’s possible, but you will need to eliminate some other possibilities first. Check supply pump pressure. You can test by installing a test gauge on the fuel/water drain line off the t-handled valve near the thermostat. Open the valve and read the pressure. It should be 3-5 psi from idle thru full throttle. If not, check the supply pump and/or oil pressure switch. The OPS switch is what turns the pump on and off. Check the glow plug operation also for hard starting. The hard cold starting may also result however from the supply pump pressure being low.
• Q: I have a lot of black smoke on hard acceleration. No smoke while cruising and my oil level is always normal. Do I have a bad PMD?
• A: It is a possibility, but it is most likely a boost pressure problem. Check your boost pressure. If stock (no chip or other mods) it should be 7-9 psi under hard acceleration, 0-3 psi cruising at 65mph. If not, check the wastegate actuator, solenoid and vacuum pressure.
• Q: In cold weather, my glow plugs don’t seem to stay on long enough to do the job. Is there a way to adjust the “time on” for the plugs?
• A: No, but I do have a solution. Our Glow Plug Over-Ride Kit allows complete manual control of the plugs for you to select how long they stay on. Just make sure you don’t have AC 9g glow plugs (92 and earlier). They will burn up quickly. Later 11g and 60g or my Instant-Heat plugs will work great as they are self regulating and will not burn up.
• Q: Will your Instant-Heat Glow Plugs fit my 6.2? And will I notice a difference over stock?
• A: Yes, a perfect fit! And yes, your truck will start like summertime all year round!
• Q: Can I mount your FSD Heat-Sync^TM on the firewall instead of the manifold?
• A: Yes, you can, but I don’t recommend it. I have done extensive testing under the hood in different locations, and our location shown is by far the coolest running. The PMD runs about 30 degrees cooler in the airstream on the manifold then even the firewall.
• Q: Can I reuse my plastic "Turbo Power" cover with your FSD Heat-Sync^TM?
• A: Several customers have notched it out to fit around my cooler, but I suggest leaving it off for increased airflow over the injection pump.
• Q: I tow a 30 foot trailer in the summers heat and my 6.5 always runs over 230 degrees. I recently cracked my heads and cost me a small fortune to repair. How can I prevent this from happening again?
• A: No diesel should run over 210 degrees for any length of time. The early 6.5’s were prone to overheating due to an undersized water pump. Our Cooling System Upgrade Kit will solve that problem. It increases water flow significantly and provides a dual thermostat housing to handle it. See our item description for more details. If towing, I also recommend our Fan Upgrade Kit. It will increase airflow by 30%.
• Q: I have a farm and have agricultural diesel fuel on the premises. Someone told me running this red-dyed fuel will not work in a 6.5 because of the optical sensor in the electronic DS4 pump. Is this true?
• A: That is pure myth! I spoke directly with Stanadyne about this subject and they claim agricultural red fuel will work perfectly in a DS4 pump. Keep in mind it is illegal to run on any highway with red fuel however. Off road use only!
• Q: How long does it take to install your FSD Heat-Sync^TM kit?
• A: 10-20 minutes depending on skill level, using basic hand tools.
• Q: I have a H1 Hummer with a 6.5 TD. Will your Heat-Sync fit?
• A: Yes, we make a special version for the H1 Hummer and G/P vans using the rear-mounted turbo. Check my product listing.
• Q: I have a 98 6.5TD and someone told me that if I replace the injection pump, it must be the same pump number DS4-5459. Is this true?
• A: No, any "reman" DS4 thru current 5521 will work perfectly. Once rebuilt, only the latest version parts are used, and all are interchangeable. Only the 1994 5068 is unique.
• Q: If I remove the PMD from the injection pump, will a "block-off plate" be required to cover the area underneath the PMD to prevent fuel leakage?
• A: No, nothing is required. The PMD was just mounted to a slab of aluminum on the side of the pump, and the screw holes are "blind" holes, they do not enter the pump and no fuel leakage will occur.
• Q: I've heard that it is best to go with a "trimmed down" Duramax fan on the 6.5 instead of the 21" fan you sell, because sagging motor mounts will cause the fan to rub on the shroud.
• A: If you have bad motor mounts you had better replace them asap for more reason then just a rubbing fan!!! Trimming a fan is dangerous at best, have seen them explode into shrapnel when that is done. By reducing fan size, you are defeating most of the benefits of having a larger fan to begin with! And the shroud is plenty large enough to fit the fan. Only slight trimming is necessary on applications where the shroud was not installed exactly concentric with the water pump shaft. A couple minutes work is well worth the benefit!
• Q: I have a set of your gauges, what are the maximum boost, EGT and tranny temps I should see?
• A: Max Boost is 15 psi sustained boost, and 17 psi max short term. EGT 1100 DF with the probe installed pre-turbo. Max Tranny temp is 240 DF.
• Q: I didn't get the life expectancy from my glow plugs as promised. Are defective plugs my problem?
• A: Not likely defective plugs. Our failure rate is .00007%. And the chances of having 8 defective plugs on the same engine are a billion to one. Here are some causes of multiple plug failures. 1) a faulty glow plug controller/relay, 2) the use of ether, even once, 3) starting your truck while connected to a battery charger, 4) jump starting your truck from another running vehicle, 5) improper use of a manual glow plug controller, 5) Advanced injection timing
• Q: How do I check and set timing on my 6.5?
• A: Beng electronic, timing is a program in the ECM. It can only be checked and set using a TECH 2 scanner made by Vetronix. Neither a Snap-On, Mac nor OTC can do it, TECH 2 only. Set base timing to 3.5 degrees with the stepper motor disabled via the TECH 2. Then, perform a "TDC Learn" procedure and set "TDC offset".
• Q: Will your exhaust systems fit my crew cab with 8 foot long box?
• A: It will fit up to a 168.5" wheelbase truck which should include your crewcab long box, But to be certain, measure your wheelbase and if 168.5" or less, its will fit. Wheelbase is wheel center to wheel center front to rear.
• Q: Where and how do I install my EGT gauge probe for best results?
• A: Pre-turbo is most accurate. Simple to do in minutes. Remove your air filter for easy access and drill a hole and tap for 1/8" female pipe thread just below the turbo mounting flange into the exhaust manifold. The probe harness will reach perfectly even with pillar mounted gauges.
• Q: How can I keep drill chips from dropping inside the exhaust manifold when drilling for my EGT probe?
• A: Simple. Drill with the engine idleing, so the chips blow out, rather then drop inside.
• Q: Where and how do I install my boost gauge connector?
• A: Its best in the upper intake manifold section. Remove the upper intake (6 bolts and a clamp) and drill a hole and tap for 1/8" female pipe thread anywhere convenient for you in that section.
• Q: Where and how do I mount the probe for my tranny temp gauge?
• A: Most 4L80E trannys have a 1/8" test plug on the side of the tranny for a technician to measure pump pressure. Just unscrew the plug and screw in the probe. It can also be mounted into the tranny pan or in a tee connection on a cooling line.
• Q: My "check engine" (SES) light comes on while driving. What is wrong?
• A: Everytime the light comes on it stores a code as to why. The codes are called DTC codes (Diagnostic Trouble Codes). You must read them and tell me the code NUMBERS that come up so I can help. A 94-95 can be read yourself with no tools. Check further in this FAQ sections for instructions. If you have a 96 or newer, you'll need a simple codes reader like our ssd-427 in the "tools" section of this website.
• Q: How long do injectors last and what are the symptoms of failing injectors?
• A: Injectors have a design life of 100K miles. They are a routine maintenance item on all diesels. Symptoms are poor performance and poor mileage. Also hard smokey starting and knocking. We offer both stock and Marine Injectors for added performance and mileage.
• Q: Can worn injectors damage my engine?
• A: Yes definately! When they wear out, they leak fuel into the cylinders washing lubricant off the pistons and cylinder walls causing catestrophic engine failure.
• Q: I just cleaned my injectors, why should I replace them? Isn't that good enough? My buddy knows a guy who works at the filling station and he says you never change them, just clean them.
• A: Injectors contain moving parts that wear and must be rebuilt or replaced every 100K miles. Cleaning only works on low mileage situations. If over 100K, just replace or rebuild them, don't mess around. How much money will you save by replacing the engine instead of injectors? Running injectors over 100K miles is like playing Russian Roulette with your engine.
• Q: How can i tell Marine Injectors from stock injectors by just looking at them?
• A: Unfortunately you can't. Reman Marine injectors use the same body as stock injectors, so external appearance looks the same. Thats why its important to only buy from a reputable source so you can trust you get what you paid for. Most cheap ones you see for sale on auctions being sold by Bubba at Jim-Bob's auto supply at a deal are probably a scam. Remember you only get what you pay for.
• Q: Can you give me some tips on installing injectors?
• A: Only handle new injectors with very clean hands and leave the plastic caps on until ready to connect the steel tubes. A spec of dirt the size of a pin point will foul an injector and create a misfire and knock. Also, never bend the steel tubes, only gently move aside. If bent, the internal coating flakes off and will also foul an injector. If bent, throw it away and install new lines. Torque injectors to 25 ft/lbs
• Q: I just installed new injectors and started the truck and it rattles like its gonna blow? Whats up with that? Bad injectors?
• A: All our injectors are tested before shipping. When first started it will rattle like its gonna blow until all air is automatically bled. Let idle 20-30 minutes or until it clears up and idles smoothly before driving.
• Q: I would like to order a SSD-Chip and I don't know where to find my stock chip code that you require. Can you help?
• A: Your stock chip is inside the ECM and is easy to access. Its about a 15 minute job. Open the glovebox door and remove the liner (4 screws). You will see a silver box on the right, thats the ECM. Its held in place by snap clips. Pull it towards you with a sharp "jerk" and it will come free. Do NOT unplug any harnesses. Snake it out towards you and turn upside down. Open the trap door on the bottom and you will see the stock chip. We need the alpha code (not numeric) from the top of the chip. It starts with a "B" and some examples are BMRL, BPAA, BPAC, BXRL to name only a few. We need this code along with your year, model, 2x4 or 4x4, auto or std tranny, and the 8th digit of your VIN code (S or F), also 40hp or 80hp desired. Enter this data on the comments section of your web order, or give to our order desk when placing an order by phone.
• Q: I have a 94 truck, how do I tell if I need a ssd-5521 or ssd-5068 injection pump?
• A: There is a metal tag rivited to the pump on the side facing the firewall. It can be read easily on the vehicle with a small inspection mirror and a flashlight. The code to watch for is 5068 as that indicates the oddball pump. If in doubt, write tech support with all the numbers on that tag, and we will advise what pump you need.
• Q: Why is 94 the only year the 5068 AND the 5067 injection pumps were used, but all other years take the same pump?
• A: I look at it this way. Remember back a few years when VCR's first came out and there was VHS and BETA? VHS won out and BETA was dropped. Same with the 5067 and 5068. The 5068 was dropped.
• Q: What is the difference between the 5067 and 5068 pumps used in 94?
• A: The difference is only in how they communicate with the ECM. They otherwise are physically idenical to the naked eye. They will not interchange however.
• Q: I just drained and refilled my coolant and now my truck overheats? Why?
• A: Probably just an air pocket from improper filling. To fill properly, open the brass air bleeder screw on the thermostat housing and fill the reservoir with 50/50 coolant until coolant flows freely from the bleeder. Pay no attention to the graduations on the reservoir, its only full when fluid flows from the bleeder. Close the bleeder and add one additional inch of coolant to the reservoir and cap off! Test and replace the reservoir cap regularily. Its critical to proper operation.
• Q: My truck came with RED antifreeze. What is it and what should I do with it?
• A: Red antifreeze is called Dexcool trademarked by GM. Its supposed to give longer life, but actually has the opposite effect. There are class action law suites open right now from folks who damaged their engines from it. It turns to mud after a while. My advice, flush it out and go with good ole GREEN antifreeze mixed 50/50. Add a bottle of "Water Wetter" by Redline and you'll have the best coolant available today.
• Q: Do you recomend any antifreeze additives or fuel additives for longevity.
• A: Yes, I recommend "Water Wetter" by Redline for the coolant system. Use the std red version and you will see a noticible difference in coolant temps. For fuel, I recommed Stanadyne's "All Season Conditioner" as sold on the website. It will add years to your injection system and also raises centane levels for more power and better mileage.
• Q: What oil should I be using in my 6.5?
• A: Use only a good diesel rated such as Shell Rotella-T 15w40 as a great std lube, or Shell Rotella-T Synthetic 0w-40 oil. Never use a gasoline rated oil such as 10w30. It must be diesel rated. The Shell products mentioned are the best made in my opinion. Our ssd-2310 oil filter also is the best filter I've found to handle the soot of a diesel. I wouldn't run anything else!
• Q: How do I read my DTC (Diagnostic Trouble Codes) on my 94-95 truck??
• A: Locate the "Data Link" connector below the steering wheel on the rim of the dash. With the key in the "OFF" position, jumper the top two right terminal pins (termnals A&B) with a paperclip or short piece of wire. Turn the key to the "RUN" position, but DO NOT START. The check engine light will begin flashing a sequence of codes. If the diagnostics are working and there are no codes in memory, a code 12 will flash 3 times. A code 12 is a flash once, followed by a quick flash two times. Basically a 1-2 flash is a code 12. If no codes, only the 12 will flash. If codes present, the sequence will start with the 12, then flash each code 3 times before moving onto the next in numerical order. When 12 flashes again, you are done. Again, count the flashes and write them down, they will flash 3 times each code. To clear the codes, depress the brake pedel and accelerator pedel simultaniously for 15 seconds while still in diagnostic mode. NOW shut off the key and remove the jumper. The codes are now cleared. NEVER-EVER remove the jumper while still in the diagnostic mode, turn key to off first. NEVER-EVER start the truck with the jumper in place. ECM damage may result. Let me know the code numbers that came up along with symptoms and I will help you diagnose your truck.
• Q: How do I read the DTC codes on my 96 and newer truck??
• A: You will need a simple code reader like our ssd-427 in the "tools" category on this website. Then let me know what codes come up along with symptoms and I'll help you diagnose your truck.
• Q: My check engine light came on, then went back out. Will I need to wait until it comes back on to read my DTC codes??
• A: No!! Everytime that light comes on it stores a code in memory until YOU clear its memory. Just read the codes by the above procedures and let me know what numbers come up along with your symptoms and I'll help you diagnose your truck.
• Q: Why don't you sell boost controllers, your competition does??
• A: We don't because we only sell products that work! Boost controllers are a hoax designed to make your wallet lighter. Raising boost only has one purpose...to allow more fuel to be burned. Just raising boost alone does nothing, it just adds air! No hp gain!! You must also add fuel at the same time as raising boost to make hp. On a 92-93 truck, you can adjust the manual injection pump. On a electronic 94-95 you need a power chip to raise boost and add fuel. On a 96 and newer truck, you need to reprogram the ECM to achieve more boost and fuel. No other way! Boost controllers just don't work! We can help you achieve power on all year 6.5s. Our ssd-chip for 94-95 trucks, and our upgrade ECM exchange for 96+ trucks is available under the "performance" section of this website.
• Q: My mileage dropped by 1-2 mpg the past couple months for no reason. Any ideas??
• A: Yes!! Since 2007 in the US, the refinerys have switched over from standard diesel fuel to the new Ultra Low Sulphur Diesel (ULSD) Fuel to meet the new federal emissions. It has its drawbacks like dropping mileage about 1-2 mpg.
• Q: Will the new Ultra Low Sulphur Diesel Fuel hurt my 6.5??
• A: Yes it may unless a good fuel treatment is used in every tank like K-100D Diesel Fuel Treatment. The new fuel does not lubricate as well and without a good conditioner as a supplement, injection pump and injector wear may occur prematurely.
• Q: Will running Biodiesel or Veggie Oil in my 6.5 cause any harm?
• A: As per Stanadyne the manufacturer of the injection pump, running more then 5% Biodiesel or Veggie Oil will void the warranty and may damage the injection pump.
• Q: I just installed my new DS4 injection pump and its now tripping a code 34. Did you sell me a bad pump??
• A: No! All our pumps are test run on a pump dyno after rebuilding. Code 34 is an installation error. Code 34 (or 216 on 96+ trucks) trips when you do not have the pump properly centered for the stepper motor to adjust timing per the ECM's command. You have it turned too far to the right or left and Its too far out of range for the stepper motor to set timing. Simple fix. If no Tech 2 scanner available, simply scribe a line on the pump and housing for a reference mark. Now loosen and rotate the pump in "hair" incriments at a time until code 34 no longer sets. Never rotate the pump with the engine running. Once code 34 no longer sets, the stepper motor is back in range and timing is correct.
• Q: What is the stock HP and Torque for the 6.5TD "F" engine?
• A: