Auto Service World
Feature   January 1, 2004   by Rick Cogbill a.k.a. Slim Shambles

Timely Advice

"Happy New Year!"...

“Happy New Year!”

The annual bash, sponsored by Herkle’s Auto Parts, was in full swing, and Herk was already deep into the beer fridge. “Happy New Year!” he hollered again as he danced a jig on top of the parts counter. In a corner by the wiper blades, Beanie was trying to keep the conversation going with Sam, the parts delivery girl, while Basil was immersed in a game of cards with Spoke Lee from the alignment shop.

These yearly gatherings felt like old home week, where you can forget about shop boundaries and catch up on gossip, or swap war stories from the year gone by. Quigley, our service writer, was checking out Herk’s latest electronic parts manuals, while Tooner was sweating it out with Dutchy the tow truck operator in an arm wrestling contest.

I looked around the store to see who else had shown up. A couple of my customers were skulking about behind the air filter shelf, but that was no surprise. Chinz Muldoon and Buck Pincher were well known around town for their penny-pinching abilities, so anytime free food and beverage were being offered, they were there, invited or not.

Dieter from The Import Shop was sitting on a stack of mufflers, deep in thought, so I went over to say hello. “Dieter,” I asked, “why so glum?”

“Cheers, Slim.” Dieter raised his glass with a sigh. “Sorry about that; got a persistent problem back at the shop.” He took another sip. “We did a routine timing belt replacement on a 2000 VW Jetta Turbo Diesel, but it’s giving us grief.”

That was odd. Dieter was the one we all turned to when we got stumped on our import cars. “Is it running poorly?” I asked. “Maybe you’re out a tooth on the belt.”

Dieter waved me off. “Nein, nein, that’s not the problem. The car runs perfectly. No, the Check Engine light keeps coming on, setting code P1248.”

“Er…right.” I answered cautiously. “And that’s the code for…for…”

“A Cold Start Injection problem.”

“Right, right.” I swirled the ice in my soft drink while I scrambled for familiar territory. “So, I take it these timing belt jobs are difficult to do?”

He rolled his eyes. “Ja, takes about 6 hours! Some of the bolts, like the engine mount bolts and the ones holding the timing gear to the injector pump, are stretch bolts. You can only use them once.”

Having never done a timing belt on a TDi, I didn’t figure I’d be of any use, but I took a stab at it. “Well, if the problem occurred right after you changed the timing belt, it sort of makes sense that it’s a timing problem. Are you sure there’s no other symptoms?”

Dieter thought hard. “Now that you mention it, the engine is a little noisier than before, but not by much.” He explained that adjusting the injection pump timing could change things like combustion noise, the amount of smoke produced, etc. “But we lock the pulleys down when we change the belt, so everything is in time like it was before. Besides, if you loosen the injection pump pulley bolts, you have to replace them…” Suddenly he stopped, a light coming on in his eyes. “I gotta go, Slim,” he said, and tossing back the rest of his drink, he ran out the door.

When I saw Dieter the next day, he gave me the rest of the story. “Fixed the problem, Slim! It was the injector timing after all.”

“Off one tooth?”

“Nope. But I had to slightly adjust the pulley, about 1 mm.” To check the timing you need to use Volkswagen’s special scan tool, Dieter explained. By following the charts provided in the repair manuals, you adjust the pulley until you get the proper relationship between fuel temperature and the start of injection timing, which can only be seen via the scan tool. On this vehicle, a slight difference in the length of the new belt had moved the setting just inside the upper limits. Once he got the readings moved down into the middle of the graph area, Dieter was able to make the Check Engine light stay out. “And it runs quieter, too,” he added.

“Wow,” I said looking at the charts he was showing me. “So it had nothing to do with any Cold Start problem.”

“No,” he replied. “And now that I’ve got that solved, I can go enjoy the New Year’s party tonight at Herkle’s.”

I looked at him. “That party was last night, Diet. I think your timing is a little off again.”

Dieter grinned. “Nope. Since I couldn’t enjoy myself until I had this solved, last night doesn’t count. I told Herk to load up the fridge again, my treat. You gonna come along?”

I shrugged. Why not? I could use another countertop dancing lesson.

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