Problem:
2002 Chevrolet Silverado 2500HD with Duramax LB7; no start after installation of injectors rebuild, water pump, FPR, and other components.
Background:
This truck only has 100K miles. It has been taken care of and serviced impeccably and I do not abuse the truck. I did not take advantage of the extended injector warranty as there was no need at the time. Truck ran great and strong with exception of idle surge and slow leak in water pump. No fuel or coolant in the oil, no codes other than a code (can’t remember the number) that dealt with either the glow plugs or glow plug controller. The truck also had clean exhaust; no smoke. Okay, all of the above background was the situation before I began working on the truck.
Present Situation:
Okay, let me begin by stating that all of the components that I replaced (I will list them below) are OEM quality GM, Bosch, AC Delco, Delphi or Gates. Secondly, and I really hope this doesn’t come off as being arrogant but, I’m extremely careful, clean and meticulous (bordering on being obsessive compulsive). I’ve worked on all types of engines, hydraulic pumps, etc. I have to admit, I’ve never been this frustrated with a mechanical problem. One more thing; and I hope I don’t hurt anyone’s feelings, but please don’t ask me if I have fresh fuel in the tank or anything like that. I have been working on this problem for over thirteen weeks and have had the help of a retired Chevrolet gas and diesel mechanic. Lastly, if you really want to help, please carefully read the entire post (novel, ha, ha) so you don’t waste your time or my time on issues that have already been addressed.
Work Done:
Before starting work I carefully cleaned the engine by applying degreaser and light pressure washing, being careful to stay away from the FICM and other electronics. It was actually pretty clean before I started and was dirt and grease free when I finished. I also took pictures of wiring routing, hose positioning and any other items that could possibly create confusion on reassembly.
First Attempt to Start Engine:
At this juncture I got on line again and started reading anything and everything about a “no-start” LB7 and did the following.
Additional Attempts to Start Engine:
This brings us up to the present. I refuse to give up on this problem, but I am at a point where I feel like pulling what little hair I have out. I am running out of ideas and need help from someone smarter and more enlightened on this subject than me. My mechanic friend informed me that his daughter, who lives out-of-town, just had a baby and that it is probably going to be a while before he can get back with me. This whole ordeal has left me with some questions that I would really like answered; they are as follows:
I really need some help on this no-start problem and I’m open to any and all reasonable solutions. Here is what I have concluded so far. It seems I am not having any problem getting fuel from the fuel tank to the fuel filter without air bubbles. I believe (but am not positive) that I am even getting fuel to the CP3, but I don’t believe I am getting any fuel out of the CP3, into the fuel rails or high pressure lines. If you remember, when I replaced the FRPS, there was zero fuel in the junction box after weeks of attempted engine starts.
After reading this novel, some of you may say, “oh, I know the problem, this guy has messed with the injectors and he either has a leak at one of the injector return lines or a stuck injector”. Well, I can’t positively rule that out, but as long (for weeks and weeks) as I have been turning this engine over I will say again, there is no fuel in the oil. As for a stuck injector, remember these injectors have new nozzles and needles inside, no gunk to hang-up the needle jet. They all slid in and out of the nozzles beautifully; no sticking. Additionally there would not have been any fuel pressure to even get the needle to stick open. Am I wrong with that analysis; if so I’m open to be corrected.
Other possibilities could maybe be a faulty FICM or ECM, but what would the odds be of one of these going out at exactly the same time I switched the injectors, since they worked perfectly before? And for those of you that may think that I messed something up electronically when I charged the batteries; I either physically remove the batteries or disconnect the negative lead before I do any charging.
What I keep coming back to is some type of an air-leak between the fuel filter and CP3. I want to believe what “chevyinlinesix” on dieselplace.com forum says in a 12/27/2012 post, My guess is there is an air leak from one of the rubber hoses between the engine's quick connect fitting and the CP3's inlet fitting. It’s like I want to believe that, and as a result I have checked all of these lines, both high and low pressure, like six times and I just don’t see where there could be a leak. I will add that I did use SS worm gear clamps on all of the new OEM low pressure hoses; but as I mentioned, I doubled them up and turned the “flat section” under the worm gear 180 degrees. After seeing the cracked and dry hoses that I removed, which still allowed the engine to start, and then looking at the brand new hoses with double clamping; I just can’t understand how they would be leaking and the old ones weren’t. But still, everything keeps pointingto a problem that is preventing the CP3 to fill the fuel rails and high pressure lines. Could I have gotten a hold of a bad hose even though it was a GM OEM replacement, and what are the odds of that? Do any of you have any other ideas how I can definitively check the low pressure lines for air leaks?
Any and all help will be greatly appreciated. I’m almost at a point to give up my first-born to get the right answer to get this rascal fixed. My name is Gary and can be reached at 256-295-7895 or garywbrock@bellsouth.net .
2002 Chevrolet Silverado 2500HD with Duramax LB7; no start after installation of injectors rebuild, water pump, FPR, and other components.
Background:
This truck only has 100K miles. It has been taken care of and serviced impeccably and I do not abuse the truck. I did not take advantage of the extended injector warranty as there was no need at the time. Truck ran great and strong with exception of idle surge and slow leak in water pump. No fuel or coolant in the oil, no codes other than a code (can’t remember the number) that dealt with either the glow plugs or glow plug controller. The truck also had clean exhaust; no smoke. Okay, all of the above background was the situation before I began working on the truck.
Present Situation:
Okay, let me begin by stating that all of the components that I replaced (I will list them below) are OEM quality GM, Bosch, AC Delco, Delphi or Gates. Secondly, and I really hope this doesn’t come off as being arrogant but, I’m extremely careful, clean and meticulous (bordering on being obsessive compulsive). I’ve worked on all types of engines, hydraulic pumps, etc. I have to admit, I’ve never been this frustrated with a mechanical problem. One more thing; and I hope I don’t hurt anyone’s feelings, but please don’t ask me if I have fresh fuel in the tank or anything like that. I have been working on this problem for over thirteen weeks and have had the help of a retired Chevrolet gas and diesel mechanic. Lastly, if you really want to help, please carefully read the entire post (novel, ha, ha) so you don’t waste your time or my time on issues that have already been addressed.
Work Done:
Before starting work I carefully cleaned the engine by applying degreaser and light pressure washing, being careful to stay away from the FICM and other electronics. It was actually pretty clean before I started and was dirt and grease free when I finished. I also took pictures of wiring routing, hose positioning and any other items that could possibly create confusion on reassembly.
- Installed a new AC Delco water pump and housing. I had the impeller and drive gear carefully welded to the shaft. Of course, used all new “O” rings and gaskets on pump and bypass pipe.
- Installed all new coolant hoses (Gates), steel idlers (Gates), thermostats (AC Delco), coolant reservoir cap and HD serpentine belt.
- Installed a new Bosch FPR. Prior to taking the old one out I sprayed the rear of the CP3 pump with carb cleaner and blew it dry with compressed air. After the old FPR was removed I took great care not to “cock” the new FPR on installation as well as very lightly coating the “O” ring with clean diesel fuel before insertion. I made 4 passes of tightening the 3 screws on the FPR so it would go in straight and then reattached the connector.
- Installed all new OEM low pressure fuel hoses. Secured the hoses using 2 worm gear clamps positioned 180 degrees apart on each end. I had taken pictures of the positioning of these hoses as well as removing and installing the new ones, one at a time so they couldn’t be connected wrong.
- Installed a new quality fuel filter. Rebuilt the priming pump on the fuel filter housing and installed a brass bleeding bolt. After pumping up the primer I checked for leaks around the top of the filter where it meets the filter housing with the big “O” ring, as well as the WIF, bleeder screw and fuel heater connection hole, all were bone dry, no leaks.
- Next came the injector nozzle replacement. Before I began, I sprayed carb cleaner around the valve covers where they would be removed and then blew everything out with compressed air a second time to make the area “squeaky clean”. During disassembly I laid everything I took off on my workbench so I would keep them in order and additionally numbered the injectors to keep them also in order. I won’t bore you with additional detail of how clean and meticulous I tried to be with the nozzle replacement (they were standard Bosch nozzles for my type of injectors). After sonic cleaning the various injector parts, I blew all orifices out with carb cleaner, then compressed air and finally WD40 to keep everything lubricated. While I was doing the nozzles I went ahead and invested in an injector upgrade kit (OEM parts) which included the improved valve seat ball, new springs, etc. for all 8 injectors. I also ohmed-out all 8 injector solenoids and found them to be fine. The injectors (other than the nozzles which were only moderately carboned-up) were surprisingly clean. I also checked, as well as I could with a magnifying glass, the valve seats which looked great with no apparent erosion. I got the injector rebuild kit with the valve cover gaskets, metal banjo gaskets for the high pressure lines, etc. I made sure to install the metal banjo gaskets right side up to avoid leaks and torqued everything down according to specs. I did decide to use the original injector high pressure lines because they were in such good shape. There was some rust on the lines where they connected to the inside section of pipe that enters into the valve cover, but absolutely no rust on any of the connecting mating surfaces. I took all eight injector lines and submerged the ends in navel jelly for about 5 minutes; they were then rinsed thoroughly, then sonic cleaned and once again blown out with carb cleaner and compressed air and finally lubricated with WD40.
- Installed 8 new U.S. made glow plugs with metal connecting straps. Old glow plugs came out fine with no damage to threads. Cleaned all wiring connections of any corrosion before reassembly.
- Installed a new glow plug controller (Delphi) and, once again, cleaned all cables and connectors of any corrosion.
- Just in case, I replaced my fuel cap with the correct GM OEM part to assure proper pressure/suction on the tank.
First Attempt to Start Engine:
- After refilling the cooling system (the complete system was drained) with the proper coolant. I then double-checked all electrical connections, charged the batteries and checked for codes. I came up with 0090 and 0193. This indicated an issue with the FPR and/or FRPS. Took the A/C compressor and other components back off where I could get to the FPR again. I unlatched the two large connectors and found the FPR purple/white stripe wire (from the wiring diagram) and corresponding pin on the large connector. Turned on the ignition and did a continuity test coming out of the ECM to the pin on the male section of the connector; I had voltage to that point. Then I needed to check continuity from the female section of the large connector back to the FPR. I was able to carefully remove the connector on the FPR with the help of some long curved needle-nose pliers and a long thin screwdriver to lift the latch. When I got it out to test I noticed the connector was cracked. Just to be sure I checked for continuity and that test failed. Ordered a new FPR connector with 6 inch leads and silver soldered the leads to the existing wiring to the FPR after cutting off the old connector and used shrink tubing on the repairs. Note that I made certain to match up the correct orientation for the two wires to make sure I did not reverse them. Ran the continuity test again at the connector, and had good voltage. Just as a test, I took the old FPR and attached it to the repaired connector and turned on the ignition; the FPR solenoid clicked on properly. Took the old one off and carefully reattached the connector securely to the new FPR and buttoned everything back up. Ran my scanner again; deleted the previous codes and re-scanned. Came up with zero codes. Ran it a second time just to be sure.
- Okay, when I ordered the connector for the FPR, I also ordered a new Bosch FRPS as well. Even though the 0193 code went away when the FPR connector was repaired, I went ahead anyway and replaced the existing FRPS and metal shim with a new one. Once again, there were zero codes. One thing that I did notice when I unscrewed the old FRPS, is that the high pressure junction box that I removed it from, had no diesel fuel in it.
- Charged batteries again and rechecked all that I had done since last attempt. Ran scan a third time; no codes. Primed fuel-filter ten pumps or so and opened up bleeder; continued pumping until nothing but steady fuel was coming out. Closed bleeder and pumped 25 to 27 times and got the pump rock-hard. Went in and turned the engine over for ten seconds or so, three times. No start. Went back and repeated above steps again. Went in and tried again in the same way; no start, not even a “kick”. I repeated the above scenario another four or five times until the batteries were drained; no start.
- Charged batteries and the next day I repeated everything over again until batteries, once again, were dead.
At this juncture I got on line again and started reading anything and everything about a “no-start” LB7 and did the following.
- Checked fuel filter housing for leaks or cracks. Pumped up primer until plunger was rock-hard; sprayed soapy water all over fuel filter and looked for leaks. No leaks found. Note that I checked for bubbles while pumping up the primer as well as when it was rock-hard.
- Pumped up primer again until hard and looked for any leaks in high or low pressure fuel lines. No apparent leaks, no smell of diesel fuel; everything bone dry. Even checked fuel lines back to tank; no leaks, everything dry.
- Crawled under truck and checked the CKP (crankshaft position sensor). Unconnected connector and checked for loose fit, corrosion or bent pins. Everything fine, reset connector into sensor.
- Crawled under truck and checked the CMP (camshaft position sensor). Unconnected connector and checked for loose fit, corrosion or bent pins. Everything fine, reset connector into sensor.
- Checked all connectors for bent pins, corrosion and loose fit on FICM and all other connectors that I could get to. All of these connections proved to be fine.
- I checked the “O” rings in the fuel line quick connects. Both lines were bone dry at the connections. By the way, when I originally disconnected them to replace the driver side injectors, I cleaned the lines at the quick connections really good with compressed air then sprayed up into the connectors with silicon lubricant so that the “O” rings would have an easier time sliding off the end of the steel lines as well as when they were to be re-attached to the steel lines later.
- I double-checked the rubber hoses between the engine's quick connect fitting and the CP3's inlet fitting. Once again, all low pressure fuel lines were replaced with new OEM hoses and the clamps were tight.
Additional Attempts to Start Engine:
- This time I went through the exercise of priming, bleeding and re-priming until the primer was rock-hard and I continued to pump the primer as a helper turned over the engine. Did this exercise many times until the batteries died; no start!
- Another attempt had me having a helper pressurize the fuel tank with 3 to 5 psi pressure by wrapping a shop towel around an air hose and holding it tight in the fuel pipe. I then went through the priming exercise again doing this procedure three times; no start, not even a “kick”. Then I did it again with the above helper pressurizing the tank and another helper (wife) turning on the ignition as I continued to pump the primer as we turned over the engine. No start!
- At this point I brought in a friend who retired from our local Chevrolet dealership with nearly 30 years-experience in gas and diesel repair. He now has his own shop. He brought over the same testing equipment that they use at the dealerships. I had the batteries charged for him and he proceeded to run his diagnostic equipment. He concurred with my diagnosis and also came up with zero codes and said that there were other tests that he would like to run, but they had to be done with the engine running. However, he went on to say that with what he could see so far we should be able to at least start the engine. We took some time to go over what I had done and he visually inspected my work. He then asked if he could do the priming himself as I turned over the engine. We did that numerous times until we depleted the batteries again. He did mention that his experiences with the Duramax engines had shown some to be especially stubborn to free all of the lines and fuel rails from air regardless of the methods used. He also mentioned that many of the no starts that came into the dealership was a result of deterioration of two flex areas in the supply fuel line coming from the tank. The first rubber hose flex section is in the engine bay on the driver’s side as the metal fuel lines come up beside the firewall. The second area is under the truck on the driver’s side roughly under the driver’s seat. These rubber sections are incorporated into the fuel lines to provide flex for the engine and any flex in the body and frame. They are installed on the larger supply line as well as the smaller return line. The problem is, after time they begin to deteriorate and soften and when suction is created (as in priming the fuel filter) they can collapse, squeeze together and prevent fuel flow. Okay, so we checked the flex fuel supply hose in the engine bay and he said it felt fine, however, when he crawled under the truck he had me squeeze the flex hose under the driver’s seat area and it was mushy. He told me how to fix it. They use a small Dremel tool to carefully cut off the crimped ends, being careful not to cut too deep and damage the steel fuel line underneath. After both ends are cut off and the old flex section is removed they install a section of premium HD hose with double hose clamps. He called the dealership and they had some in stock. It was heavy duty Parker hydraulic hose about 10 to 11 inches long. It took me about 45 minutes to do the whole job. I checked for leaks and recharged the batteries. My mechanic friend told me that he had six cars ahead of me, but wanted me to go ahead to see if I could get it started after I made the hose repair and that he would get back with me after he cleared out some of the cars he was working on. I, once again, went through the proper priming exercise and tried to start the engine, priming and turning over the engine 5 times. No-start!
This brings us up to the present. I refuse to give up on this problem, but I am at a point where I feel like pulling what little hair I have out. I am running out of ideas and need help from someone smarter and more enlightened on this subject than me. My mechanic friend informed me that his daughter, who lives out-of-town, just had a baby and that it is probably going to be a while before he can get back with me. This whole ordeal has left me with some questions that I would really like answered; they are as follows:
- The first question is, when I pump up the primer on the fuel filter and get it hard; is it supposed to remain hard over an extended period of time or is it natural for it to slowly lose pressure? The reason that I ask is that when I pump mine up and get it rock-hard it doesn’t take it long before I have to pump it up again to make it hard again. The information on-line has been contradictory; some sources say that even on an engine that runs and starts fine, the fuel primer will slowly lose pressure, other sources say no, the primer should continuously stay hard. Which is correct?
- The next question is a big one for me because the answer to it is going to determine whether I have a lot more work in front of me or whether I can simply focus on getting the engine started. The question is this; do you think I have a faulty FPR? I have tried to learn everything I can about the FPR and its role in the fuel delivery system. As explained earlier, I replaced the original FPR with a new Bosch sealed box replacement. And as I confirmed earlier I know that I have power going to the FPR and I further know that when I repaired the FPR connector we eliminated the 0090 and 0193 codes. So my question is this, can the scanner show that there is no code for the FPR but still have that FPR be faulty; and how common would it be that I would receive a faulty FPR from Bosch? If I have to go in and replace it I have to drain the coolant and tear the top of the engine down again; I really don’t want to do that based simply on “maybe” the FPR was bad. Okay, here is the last question regarding the FPR. It seems to me to be another contradiction in regard to what I am learning on-line and in repair manuals. According to what I have learned, the FPR doesn’t really regulate fuel pressure; it controls the volume of fuel to the high-pressure side of the CP3 pump. Okay, if that is the case, does that mean that it is absolutely essential that the FPR be functioning properly for the engine to start or does it simply mean that the FPR is absolutely essential for the engine to run smoothly and efficiently after it is started? I have read some diesel blogs where they are saying how they disconnected the FPR then ran the engine to test for other issues. Are they saying that yes, the engine can be at least started without the FPR being energized? The reason that this question is so important to me is that if the FPR is not absolutely essential to start the engine, then I have to look elsewhere for the no-start problem.
- Another question; or maybe this is simply a recommendation. Should I install a lift pump? Before you answer that question let me tell you what I need out of my truck. I will be using this truck pretty much for only one thing; pulling a car trailer for restored antique MGA sports cars (they are small). I belong to an MG club and we have meets all over the U.S. where we trailer in our cars. Just so you understand, I’m not pulling a huge fifth wheel travel trailer or anything really heavy, just a relatively lightweight trailer with a small sports car. Also, I’m not interested in modifying my engine to develop 700HP; what I am interested in is reliability and longevity. So, once again, do you think I need to install a lift pump?
- Another component that I plan on installing, after I solve the no-start problem, is an upgraded fuel filter system with or without a lift pump (need your recommendation).
- Are there any other upgrades to engine or transmission that you would recommend to help my engine and/or transmission be more efficient or reliable? I wasn’t even going to mention this because I didn’t want to “muddy-the-waters”, but I did purchase a PPE Xcelerator Tuner. I have not installed it and even if I do, I will only use the stage 1 tune which only provides the 40 HP increase. As I said, I have not even attempted to install it yet so this has nothing to do with the no-start.
I really need some help on this no-start problem and I’m open to any and all reasonable solutions. Here is what I have concluded so far. It seems I am not having any problem getting fuel from the fuel tank to the fuel filter without air bubbles. I believe (but am not positive) that I am even getting fuel to the CP3, but I don’t believe I am getting any fuel out of the CP3, into the fuel rails or high pressure lines. If you remember, when I replaced the FRPS, there was zero fuel in the junction box after weeks of attempted engine starts.
After reading this novel, some of you may say, “oh, I know the problem, this guy has messed with the injectors and he either has a leak at one of the injector return lines or a stuck injector”. Well, I can’t positively rule that out, but as long (for weeks and weeks) as I have been turning this engine over I will say again, there is no fuel in the oil. As for a stuck injector, remember these injectors have new nozzles and needles inside, no gunk to hang-up the needle jet. They all slid in and out of the nozzles beautifully; no sticking. Additionally there would not have been any fuel pressure to even get the needle to stick open. Am I wrong with that analysis; if so I’m open to be corrected.
Other possibilities could maybe be a faulty FICM or ECM, but what would the odds be of one of these going out at exactly the same time I switched the injectors, since they worked perfectly before? And for those of you that may think that I messed something up electronically when I charged the batteries; I either physically remove the batteries or disconnect the negative lead before I do any charging.
What I keep coming back to is some type of an air-leak between the fuel filter and CP3. I want to believe what “chevyinlinesix” on dieselplace.com forum says in a 12/27/2012 post, My guess is there is an air leak from one of the rubber hoses between the engine's quick connect fitting and the CP3's inlet fitting. It’s like I want to believe that, and as a result I have checked all of these lines, both high and low pressure, like six times and I just don’t see where there could be a leak. I will add that I did use SS worm gear clamps on all of the new OEM low pressure hoses; but as I mentioned, I doubled them up and turned the “flat section” under the worm gear 180 degrees. After seeing the cracked and dry hoses that I removed, which still allowed the engine to start, and then looking at the brand new hoses with double clamping; I just can’t understand how they would be leaking and the old ones weren’t. But still, everything keeps pointingto a problem that is preventing the CP3 to fill the fuel rails and high pressure lines. Could I have gotten a hold of a bad hose even though it was a GM OEM replacement, and what are the odds of that? Do any of you have any other ideas how I can definitively check the low pressure lines for air leaks?
Any and all help will be greatly appreciated. I’m almost at a point to give up my first-born to get the right answer to get this rascal fixed. My name is Gary and can be reached at 256-295-7895 or garywbrock@bellsouth.net .