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Engine Specific Info and Questions => TDI Engine -General Info => Topic started by: paolomarks on March 20, 2014, 08:51:57 am
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My friend has a 99 jetta TDI manual tranny. IP has been leaking and I've told her I'd help her with it.
I've re sealed a 1.6na pump and an AAZ pump successfully while they were out of the vehicle, but have never done a TDI. Which seals can I replace while it's in the car? Hard to see which seal is leaking(pump is filthy) The pump leaks enough that if you let the car sit for a few days it needs to be primed in order to start. Does this suggest a certain seal? Thanks in advance, Paolo.
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I'd put a clear lines on the IP and see where the air is getting in.
I'd also check the tee-fitting on the fuel filter. It can let in air when the car sits and fuel will siphon out of the IP.
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Thanks for the reply. A problem with the T fitting would siphon fuel out the IP back to the tank? It would not leak fuel out the seals of the pump, right?
Will I be able to replace the IP shaft seal and top gasket with out a Vag com? Thanks, Paolo.
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When either line has a leak, air pressure and gravity pulls the fuel toward the tank in both lines, when the engine is off.
Even if the leak is in the return line, if the car sits long enough the supply line will siphon out the IP.
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Assuming the return and feed lines are fine, is it indeed possible for a pump to lose prime over a couple of days just from leaky seals? If so , which seals might be the most likely culprits, and can they be replaced in-car and without afterwards needing a vag-com to recalibrate the pump. Thanks, Paolo.
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Wash the pump and then drive it and look for leaks.
You can replace the very top cover without VAGCOM. You can actually do all the seals except for the one below the top cover, where the top (actuator) sits on the pump body. Do not try and take out the 4 small torx? screws on the electrical connector on the pump. That seal is not serviceable.
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The top plate seal you can change easy, but you need a special tool to remove a triangle bolt. Theres DIY for TDI pump on youtube changing the seals w/o removing the injection pump. Bosch kits are only like 12$ and comes with all the serviceable seals and crush washers.
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If the black electrical box is leaking u screwed, pump at that moment as no one has them, ive looked high low with no success, so go look now...
What car, engine?? Ill be pulling good mk3 pump off jetta today thats getting a rover pump... Im in athens ohio this week at vw shop specializing in diesels, so close to wv too, i know it will be 4sale
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So we're still trying to figure out the problem with my friends 99.5 Jetta TDI(AHU) We put a vacuum fuel extractor on the IP return and a steady foam of bubbles comes out. The IP intake hose has no bubbles. I took off the timing belt cover and it seems pretty dry in there(Shaft seal OK?) Is there anywhere else to do or check before replacing IP cover seal and actuator seal? After drawing fuel(and bubbles) through the IP we cranked it over while I bled air out of the steel lines at the injectors. Engine sounds like it wants to start but wont. Thanks in advance, Paolo.
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Pull the pump and reseal everything. I chased problem with losing prime and very poor hot restarts for 3 months until I jerked the pump and resealed everything. I never did figure out where it was leaking air. Never leaked a drop of fuel, but it would not hold vacuum. I replaced all of the seals that you can get with the pump in the car, to no avail. After the complete reseal, no problems.
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The shaft seal is under vacuum when the pump is running as it is covering the vane pump. If it has a small leak it often will let air in to the pump without leaking any fuel out.
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OK, so it seems like the problem is with the pump letting in air. I don't have a Vag com, If I pull the pump and reseal everything will I be able to time it afterwards. I have the dial indicator for the IDI engines. Thanks, Paolo.
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If you've got the dial indicator you'll probably be OK. Measure it before removing the pump and set it back exactly the same. The computer will take care of small adjustments on its own.
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You can't use the IDI timing gauge on the TDI, the thread diameter is different.
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The thread diameter is the same, but the timing plug has a tapered cone end to it and the large triangle nut has a smaller diameter hole. You can swap on one of the large triangular nuts from an IDI pump and the timing gauge will work fine.
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Hello again,
So I took out the IP and completely resealed it. I re- installed it so that at TDC the camshaft slot is parallel to the head deck and the timing pin slides through the IP pulley and smoothly into the backing plate hole. I primed the IP by using my vacuum extractor on the IP return line, and then cranked the engine while bleeding each of the hard lines. Engine cranks fast and white smoke comes out the exhaust, but no start. It will catch once or twice but that's it. Engine has 260,000 miles and compression is untested. I've heard that TDI's don't need the glowplugs to start when it's warm weather like it is now. I haven't tested the plugs, is it possible that that's where the problem lies? Is it possible that the IP timing is 180 off? Thanks in advance, Paolo.
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If you pulled it apart as deep as the camplate, it is possible to assemble 180° out. Otherwise, when you say the cam was parallel, was it aligned with the edge of the head or offset from it? If offset, then it would be 180° off.
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Hello,
I just went out and disconnected the no.1 hard line at the fuel distributer. Next I turned the engine over by hand until the IP pulley was just before the point where the pin slips in,(about to inject no. 1 ) then I had someone bump the starter less than 1/2 rotation of IP pulley. A dribble of fuel came out indicating that indeed the pump is not 180 out. Did this a couple of times to be sure.
The camshaft is also not 180 out as the slot is even with deck and not offset and the lobes of cylinder 1 are both up at TDC.
When I turn the key to the start position the glowplug light illuminates for less than a second and then goes out. Does this mean that the glow plugs are energized for only 1/2 second or is it just an idiot light saying that the glowplugs are indeed working? I put my clamp- on ammeter on the red line going to the glow plug harness and didn't see anything while in the start or crank positions. Glow plug fuse looks fine.
I'll let it crank fast for 5 or 10 seconds and sometimes it will catch briefly before resuming normal crank speed/sound. Plenty of white unburned fuel coming out the exhaust pipe, but no start. I had a Saab 900 (gas of course) that had a plugged cat converter that would do the same, too much back pressure. Could this be the case here as well? Thanks, paolo.
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Glowplugs are a red herring. TDIs won't need glow plugs until ambient temps are down around freezing.
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I had heard the same thing about TDI's , but just for kicks I went out and wired the glow plugs directly to the battery and tried cranking her. Where before, it caught only once or twice, now it was on the verge of running and when I stopped cranking it actually ran for maybe 1 second! So glow plugs are not the answer, but does this give a clue as to the underlying problem. Also I noticed that the tachometer was pegged during cranking, even though I'm sure the engine never went more than a fast idle. Is this also a clue as to what's wrong. Paolo.
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Hello again,
Is it normal for the fuel shutoff solenoid to click open when the key is turned to the on position,but then click off after 5 seconds even though the key is still in the on position.? Paolo.
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Hello,
I got it up and running! Ended up putting a 3-5psi lift pump before the IP and that seemed to do the trick. It smokes more than it should however. It's a white unburned diesel smoke. I realigned the quantity adjuster cover back to my scribe marks, but don't have a vag com to do IQ. I read somewhere that you can download a free version from Ross tech? Alternatively, can I tap the cover one way or the other until smoke reduces and call it good? Getting close! Paolo.
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This all sounds like very retarded IP timing. I would bump it up a bunch and see what happens.