csigona
Active member
2002 Jetta TDI ALH engine
I used to have a leak at the large ring head seal of the injector pump. I replaced the seal and a new leak, under the quantity adjuster, appeared. I guess after I replaced the head seal, the middle seal became the weak spot. I left it leaking for a while since the engine was running nicely. Last weekend I replaced the top and middle seals. I noticed that the mechanism just under the cap (fuel temperature sensor?) is rusty. I can't say how water got in there, but it must have been from before I owned it. Since everything had been running fine even with the rust, I left it alone, and put everything back together. But now starting became very hard. I bled the fuel line, the injector pump, and the injectors. After a lot of cranking, the engine started but it was rough. I noticed the injection quatity was a little off (compared to the initial setting), so I tapped the quantity adjuster until the setting was the same as it was at the start. This calmed down the idle, but it's still very hard to start when cold. Note that the cold start issue only started right after I fiddled with the top and middle pump seals, so I'm guessing something went wrong when I reassembled the pump.
I checked the glow plugs. They're OK. Besides it's unlikely they would have been disturbed by my injector pump work.
I checked the timing with VCDS. It's slightly advanced but well within spec.
My current hypothesis is that the cold start injector valve is not working. Either something is jamming it or the electric wire going to it is bad. Maybe I pulled the wire and a precarious connection is now shot?
Any other ideas?
List of symptoms:
1. Very long (30 seconds) cranking to start. When the engine starts, it is somewhat rough but calms down as it warms up.
2. I can drive the car. It has power, even climbing hills. I wouldn't notice there were trouble except for the hard start.
3. If I run the engine at 2500-3000 rpm with the car parked in the garage, it seems that the exhaust is wet with excess fuel. After 10 minutes or so, there's an oily patch on the ground. It doesn't seem right, but I never ran it at 3000 for 10 minutes in park before.
4. No check engine light. No set codes. No pending codes.
5. VCDS shows the cold start valve setting varying nicely. It up around 70% when cold and will go down below 10% when the engine is warm. I don't know that the valve is doing anything, only that the number seems to be within spec.
6. Click noise in fuel injector pump, which I didn't notice beforehand.
I used to have a leak at the large ring head seal of the injector pump. I replaced the seal and a new leak, under the quantity adjuster, appeared. I guess after I replaced the head seal, the middle seal became the weak spot. I left it leaking for a while since the engine was running nicely. Last weekend I replaced the top and middle seals. I noticed that the mechanism just under the cap (fuel temperature sensor?) is rusty. I can't say how water got in there, but it must have been from before I owned it. Since everything had been running fine even with the rust, I left it alone, and put everything back together. But now starting became very hard. I bled the fuel line, the injector pump, and the injectors. After a lot of cranking, the engine started but it was rough. I noticed the injection quatity was a little off (compared to the initial setting), so I tapped the quantity adjuster until the setting was the same as it was at the start. This calmed down the idle, but it's still very hard to start when cold. Note that the cold start issue only started right after I fiddled with the top and middle pump seals, so I'm guessing something went wrong when I reassembled the pump.
I checked the glow plugs. They're OK. Besides it's unlikely they would have been disturbed by my injector pump work.
I checked the timing with VCDS. It's slightly advanced but well within spec.
My current hypothesis is that the cold start injector valve is not working. Either something is jamming it or the electric wire going to it is bad. Maybe I pulled the wire and a precarious connection is now shot?
Any other ideas?
List of symptoms:
1. Very long (30 seconds) cranking to start. When the engine starts, it is somewhat rough but calms down as it warms up.
2. I can drive the car. It has power, even climbing hills. I wouldn't notice there were trouble except for the hard start.
3. If I run the engine at 2500-3000 rpm with the car parked in the garage, it seems that the exhaust is wet with excess fuel. After 10 minutes or so, there's an oily patch on the ground. It doesn't seem right, but I never ran it at 3000 for 10 minutes in park before.
4. No check engine light. No set codes. No pending codes.
5. VCDS shows the cold start valve setting varying nicely. It up around 70% when cold and will go down below 10% when the engine is warm. I don't know that the valve is doing anything, only that the number seems to be within spec.
6. Click noise in fuel injector pump, which I didn't notice beforehand.
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