adiaireton8
Member
My 98 Jetta has 171k; last TB change was at 118k. Injection pump was replaced in Feb 2008 (by the dealer for $1400). Fuel filter replaced at 166k.
The CEL has been coming on since May of 2009. Each time it is Fault code 00550 "Start of injection regulation 17-10 Control Difference - Intermittent". I've noticed general loss of power and loss of acceleration. The engine runs noisier, clankier. It also seems to run cooler (the needle now runs about 15 degrees cooler on the temp gauge). Today I pulled the fuel line where it goes into the fuel filter, and used a hand-squeeze vacuum pump to pull fuel from the tank. No fuel-flow restrictions there; I was able to draw fuel easily. I watched the engine run at idle with the engine cover removed; no air bubbles in the fuel lines. I cleaned out the snow screen. No difference. About three years ago I replaced all the vacuum lines with silicone hoses, so I don't think they're leaking. Tonight I put the Vag-com on and wrote down some numbers:
At idle, the specified start for injection is 1.1 BTDC, while the actual is 5.5 BTDC. The coldvalve is at 2.8% (and that stays pretty much the same from idle to over 2000 rpms).
In the basic setting (at idle), group 000, the numbers are: 043, 108, 000 116, 096, 200, 077, 153, 141, 145.
In the normal setting (at idle), group 004, the numbers are: 043, 106, 000, 015, 096, 200, 079, 153, 141, 083.
At idle, the MAF specified is 250; the actual is 502.
At idle (903/min), group 008: the injection quantities are 0.0, 28.4, 22.0. Even when I raise the rpms, the first number stays much lower than the other two.
When I try to graph the timing, Vag-com says that the timing is too advanced to graph.
Any suggestions? Red flags? Could the timing belt have slipped a tooth or stretched? Or should I try to solve this by retarding the timing, using the "mechanical adjustment" method, rotating the injection pump forward? I also wondered whether it could also be a restricted catalytic converter, or a partially-plugged injector. I understand that faulty N108 or faulty G80 are also causes of the this fault code. How do I go about testing those?
I'm very grateful for any advice.
The CEL has been coming on since May of 2009. Each time it is Fault code 00550 "Start of injection regulation 17-10 Control Difference - Intermittent". I've noticed general loss of power and loss of acceleration. The engine runs noisier, clankier. It also seems to run cooler (the needle now runs about 15 degrees cooler on the temp gauge). Today I pulled the fuel line where it goes into the fuel filter, and used a hand-squeeze vacuum pump to pull fuel from the tank. No fuel-flow restrictions there; I was able to draw fuel easily. I watched the engine run at idle with the engine cover removed; no air bubbles in the fuel lines. I cleaned out the snow screen. No difference. About three years ago I replaced all the vacuum lines with silicone hoses, so I don't think they're leaking. Tonight I put the Vag-com on and wrote down some numbers:
At idle, the specified start for injection is 1.1 BTDC, while the actual is 5.5 BTDC. The coldvalve is at 2.8% (and that stays pretty much the same from idle to over 2000 rpms).
In the basic setting (at idle), group 000, the numbers are: 043, 108, 000 116, 096, 200, 077, 153, 141, 145.
In the normal setting (at idle), group 004, the numbers are: 043, 106, 000, 015, 096, 200, 079, 153, 141, 083.
At idle, the MAF specified is 250; the actual is 502.
At idle (903/min), group 008: the injection quantities are 0.0, 28.4, 22.0. Even when I raise the rpms, the first number stays much lower than the other two.
When I try to graph the timing, Vag-com says that the timing is too advanced to graph.
Any suggestions? Red flags? Could the timing belt have slipped a tooth or stretched? Or should I try to solve this by retarding the timing, using the "mechanical adjustment" method, rotating the injection pump forward? I also wondered whether it could also be a restricted catalytic converter, or a partially-plugged injector. I understand that faulty N108 or faulty G80 are also causes of the this fault code. How do I go about testing those?
I'm very grateful for any advice.