carlosbeldia Posted October 16, 2011 Share Posted October 16, 2011 My TD5 fuel pump broke last week (sending 38 PSI instead of 58). Tired of reliability lack of original spare (2 pumps in 30.000 km), I went the hard way trying to make a better car. I installed an external pump and an additional filter. Right now, pump is sending 60 PSi to the regulator, regulator makes the fuel route OK, taking out the excess througn the fuel cooler with no problem at all. As only have one HP stage, I had to eliminate the original filter housing arrangement and blocked one out and one return. Right now, the car have one HP stage going through a new inline filter and original filter, getting the fuel cooler line as the only return one (blocked in housing both purge return and fuel cooler return), so I have no clear view in how the car can make a complete bleeding. When you make the normal bleeding procedure, you can hear air bubbles noises coming from filter and regulator, but after some cycles, they disappear. However, the car crancks but doesn't tries to fire.... I have checked: - CKP - ECU loom oil (also Nanocom seems everything fine, no reporting errors at all) - Pre heat sparks (really not a matter, I'm 35ºC in a cold day) - Fuses - Relays - Sensors - Fuel filters are new - Battery is a 1400 amp, but right now it's sending only 12.2V, left tonight charging) - New external pump creates a minimum of 7.6 bar, 0.6 in excess of original, 50GPH flow, 2 in excess over original one. Both measures are compensated by additional filter - For test purposes, additional filter was taken off with same result, car crancking but no firing - Oil doesn't seem to have diesel (thick oil, no rising level), but not sure if injector seals are damaged. Can this make a difference so big it can't start? The day before the car was running and starting ok... Quote Link to comment Share on other sites More sharing options...
carlosbeldia Posted October 16, 2011 Author Share Posted October 16, 2011 Please!!!!!!!!! any idea will be welcome.... Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted October 16, 2011 Share Posted October 16, 2011 Are you putting your new HP feed through the original filter? IIRC the Td5 filter is designed to work with low pressure, hence the additional LP circuit on the standard pump. If your new filter is designed for HP then use that in-line between the pump and the engine. Could you perhaps draw us a diagram of your fuel layout, and how it differs from this (standard): Quote Link to comment Share on other sites More sharing options...
Guest Posted October 16, 2011 Share Posted October 16, 2011 I know when I change my fuel pump I had two issues, a slight air leak (clip not 100%) second issue was clearing the air from the system, I purged and Purged and Purged but to no avail, in the end a tow start was the only way to get it going. Jason. Quote Link to comment Share on other sites More sharing options...
carlosbeldia Posted October 16, 2011 Author Share Posted October 16, 2011 Hi there. I'm using the original filter, since it's designed for high pressure and flow (top 5 bar and 180 L/hour), obvisuly with a decrease in filtering efficiency. In the afternoon, I'll post a diagram. Tired of finding fuel faults, I went for the ECU..... it had high humidity levels, taking off the plastic paper that cover the circuit and showing some rust problems in one or to internal connectors..... Illk try to take one or two photos to show you.... Quote Link to comment Share on other sites More sharing options...
carlosbeldia Posted October 16, 2011 Author Share Posted October 16, 2011 Look how is the interior of the ECU. Are all these wrinkels ok? Quote Link to comment Share on other sites More sharing options...
carlosbeldia Posted October 16, 2011 Author Share Posted October 16, 2011 How can I be sure that my ECU is OK? everything looks fine in Nanocom, all outputs mark correctly, but still nothing. One think looks really weird to me: if you take the CKP sensor out and then try to start the engine, Nanocom doesn't shows any error.... is this correct? Quote Link to comment Share on other sites More sharing options...
Dave W Posted October 16, 2011 Share Posted October 16, 2011 Just to be sure, when you say "normal bleeding procedure" what exactly are you doing ? Is the original filter still in the return circuit or have you moved it into the HP side ? If it's in the return are you sure you've blocked off the correct ports as blocking off the wrong one will result in the fuel regulator not working ? Is the additional filter on the pickup or output side of the new pump ? It sounds as if you've checked the fuel return has fuel coming back to it from the regulator, is that correct ? Quote Link to comment Share on other sites More sharing options...
carlosbeldia Posted October 16, 2011 Author Share Posted October 16, 2011 Fuel is getting out from rail through the regulator, it goes to fuel cooler and after it goes to the tank. I blocked 1 input and one output, only using 2 ports in the filter and 2 ports in the tank. Pressure before the FPR is 60 PSi, getting good flow in FPR return hose, so I think it's working right both the fuel pump and the FPR.... Additional filter is before the pump. Today I tried a new approach using an internal fuel pump ( filter at 30 cm from the pump) with same results, 60 PSi in FPR still not responding..... Bleeding procedure is 5 hits to throttle and complete cycles. We also tried with purge port in the housing.... We are running out of ideas and here we don't have spare parts easily to try..... what do you think on the ECU? Engine harness coming from the injectors (the one with the round loom) was kind of dirt and you could see some steel in the cables, so electrical tape and cleaning.... still no results..... Quote Link to comment Share on other sites More sharing options...
Dave W Posted October 16, 2011 Share Posted October 16, 2011 Given it was working before you modified the fuel system and stopped working immediately after I'd be extremely surprised if it was an ECU problem. I guess the ultimate test of that is to put the fuel system back to how it was and see if it will run... I wouldn't do that until you've investigated all the other options though ! Just to be sure, the official procedure (or at least the one I know of !) for purging the air is... Turn the ignition off for at least 15 seconds as this makes sure the ECU resets. Turn the ignition key to position 2 and wait 3 minutes (this purges any air from the fuel rail) Push the throttle to the floor and crank the engine keeping the throttle wide open (it needs to be more than 90% throttle or the purging ceases) and you need to crank continuously as stopping cranking will also stop the purging. Max cranking time is 30 seconds, if it doesn't start after 30 seconds you have to repeat. If you do have air in the system it will be between the regulator and the injectors and the above steps will "tell" the ECU that it needs to open the injectors for a longer period than normal so the air has a chance to bleed through. Because of that though, using it when there isn't air in the system can flood the cylinder with too much fuel making it difficult to start. Quote Link to comment Share on other sites More sharing options...
carlosbeldia Posted October 16, 2011 Author Share Posted October 16, 2011 OK, I didn't know that procedure... tomorrow I'll go for it. Right now is not possible to go to original system, fuel pump will arrive until friday, my original died, or at least I think so. Did you see the pictures? do you think it's normal the wrinkles the plastic have? Quote Link to comment Share on other sites More sharing options...
Dave W Posted October 16, 2011 Share Posted October 16, 2011 The ECU pics look OK, I don't think it's anything unusual or worth worrying about. Quote Link to comment Share on other sites More sharing options...
carlosbeldia Posted October 17, 2011 Author Share Posted October 17, 2011 Ok, thanks a lot. I think I'm not sleeping tonight...... Quote Link to comment Share on other sites More sharing options...
Escape Posted October 17, 2011 Share Posted October 17, 2011 Have to tried to reset the inertia switch? Quote Link to comment Share on other sites More sharing options...
C18RCH Posted October 17, 2011 Share Posted October 17, 2011 I know when I did mine last it was a pain to bleed the system. Despite the manual saying no bleeding is required. After a bit of digging I eventually found a bleed procedure as described above. I had to repeat it several times before it worked. Subsequentley I've found if you repeat steps 1 & 2 (below) three or four times before trying step 3 it will usually work first time. 1. Turn the ignition off for at least 15 seconds as this makes sure the ECU resets. 2. Turn the ignition key to position 2 and wait 3 minutes (this purges any air from the fuel rail) 3. Push the throttle to the floor and crank the engine. Quote Link to comment Share on other sites More sharing options...
carlosbeldia Posted October 17, 2011 Author Share Posted October 17, 2011 Thanks a lot, I'm leaving to the workshop to try it... Quote Link to comment Share on other sites More sharing options...
carlosbeldia Posted October 17, 2011 Author Share Posted October 17, 2011 Using this method it tries to fire in a really weak way, but still not starting....... I have just measured the pressure before and after the filter, and it's almost exactly the same.... is that correct? our filters have a bypass valve? another interesting thing is that pressure goes straight to the top, but when pump stops, it drops to zero inmediatly.... isn't it supposed to maintain certain pressure with the pump off? Quote Link to comment Share on other sites More sharing options...
SteveG Posted October 17, 2011 Share Posted October 17, 2011 OK, I didn't know that procedure... tomorrow I'll go for it. Right now is not possible to go to original system, fuel pump will arrive until friday, my original died, or at least I think so. Did you see the pictures? do you think it's normal the wrinkles the plastic have? It's impossible to visually verify whether ECU is faulty, unless of course you see something obvious like broken tracks. If you are concerned about ambient temps and humidity where you are, you could consider encasing the ECU in a suitable electrical resin. This would stop condensation building up in the ECU case and affecting the board over time. Quote Link to comment Share on other sites More sharing options...
Dave W Posted October 17, 2011 Share Posted October 17, 2011 Using this method it tries to fire in a really weak way, but still not starting....... I have just measured the pressure before and after the filter, and it's almost exactly the same.... is that correct? our filters have a bypass valve? another interesting thing is that pressure goes straight to the top, but when pump stops, it drops to zero inmediatly.... isn't it supposed to maintain certain pressure with the pump off? If you've not done so already I'd bypass the original filter altogether, even if it means putting the return form the fuel cooler into a jerry can as a temporary test. There shouldn't be any real pressure at all on the return system - any pressure there will just mess up the regulator. In fact in your situation I'd probably try running the engine from a jerry can with the pump and the return both picking up from the jerry can. That way you're sure you're not trying to pick up fuel or return it through a one way valve in the original pump and filter assemblies. You would expect the pressure to drop when the pump isn't running as there is no none return valve. Quote Link to comment Share on other sites More sharing options...
carlosbeldia Posted October 17, 2011 Author Share Posted October 17, 2011 But the pressure in zero? isn't that to much? I'll try with no filter at all...... Quote Link to comment Share on other sites More sharing options...
mturri Posted October 18, 2011 Share Posted October 18, 2011 Carlos, This is the stock Td5 fuel delivery system: If I'm reading you correctly you're using the original filter as an HP stage filter and going straight to the engine, then on exiting the FPR taking returns through the fuel cooler and back to the tank. If that's the case then the system has indeed lost its ability to self purge!! To try get the air out and the engine started, you could temporarily run the HP line straight to the engine, then route the return from the fuel cooler to the filter housing (just block the LP feed --blue line) so that diesel can go back to the tank the normal way (black line) and all that air gets purged out! (white line) Re your ECU it looks completely normal -- that's isolating varnish there. As said if it was working the day before no reason to believe it's failed. Re the system de-pressurising albeit nothing particularly wrong with it, it is due to --as pointed out by Dave W-- the absence of the non return valve which if installed sits where the LP feed enters the filter housing. Quote Link to comment Share on other sites More sharing options...
isbjorn Posted May 25, 2012 Share Posted May 25, 2012 hmm, reminds me of my problem, did you ever solve it? Quote Link to comment Share on other sites More sharing options...
carlosbeldia Posted May 26, 2012 Author Share Posted May 26, 2012 I had to import the VDo pump.... I couldn't put order in my fuel lines Quote Link to comment Share on other sites More sharing options...
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