Luis de Prat

True to everyone's claims about how awesome this upgrade is, our S2 cab's headlights are now beaming better than ever. Thanks IceShark! It's amazing how warm it feels just standing in front of them in the low beam position.

However, after buttoning everything back up, there is an awkward hesitation upon acceleration while driving. The car loses power almost to the point of cutting out and then recovers slowly.

I didn't do the installation myself, for lack of time but had a competent electromechanic shop replace the voltage regulator and run the new wiring harness. I was present during much of the work and everything was done following the instructions provided with the kit, down to the hole and grommet for the direct feed in the alternator shield, auxiliary ground, etc.

The battery was disconnected during the install. What could be wrong? I wonder if there could be a vacuum leak from having removed the air flow meter? The mech was experienced enough to replace the voltage regulator without taking out the alternator using a mirror, but I remember we had some trouble getting the plastic shield back into position, possibly knocking the throttle position sensor a bit, although I don't see how that could've harmed it?

Your advice and suggestions are appreciated. TIA.

IceShark

Luis, Check to see if all the air intake hose clamps were tightened back up. I've forgotten this myself a couple times. Vacuum hoses next. Then the electrical plugs that were pulled like the MAF & TPS. That should cover it.

Hope your Dad likes the lighting!

Scootin159

Yeah, I highly doubt that it was any of Iceshark's components that messed up the install. It was most likely that either one of the small vaccum lines got disconnected in the install or a loose hose clamp, or something like that. Not to say your mech. was incompetant though, even the most experienced mechanics sometimes forget a small line or a hose clamp every so often.

Campeck

hmmm. interesting

Luis de Prat

Problem solved!

And Scootin159, I was not implying "that it was any of Iceshark's components that messed up the install," just asking what we could have done wrong during the reassembly. I asked publicly on the forum for a quick response, since so many 'listers have successfully done this upgrade.

As it turns out, the problem was caused by a loose alternator bolt !

I took it back to the mech. He spotted it and tightened it up, and now the car is back to normal. Can't wait to see those laser beams of death tonight!

Hans

Luis: you will be pleasantly surprised
It will strongly resemble the good old "battle field illumination": you will have the road illuminated till 100 meter from your bumper.
If you wait too long for a traffic light you can fry an egg on the lenses so don't touch them!!!
TakeCare

IceShark

Luis, loose alternator bolt?! You must have been lugging the engine because the alternator/AC belt wanted to jump off due to misalignment. Those 6 rib belts are pretty darn strong and I could see one actually stopping an engine at idle without too much problem.

Well, you have the problem fixed and can now enjoy burning up the night. And the hair off any critters that wander in front of you.

Luis de Prat

OK, they just called me to tell me it's back again. What exactly do you mean by misalignment? Could the alternator bolt have backed out again due to improper tension of the accessory belt so now it's misaligned again?

IceShark

Luis, that would be my guess. The alternator/AC belt is supposed to be tensioned at 85 lbs. That is very tight, indeed. So if a mechanic hasn't tightened up the mounting bolts and adjustment turnbuckle properly I could see things getting out of whack and the belt wanting to jump off. And the turnbuckle can snap in a couple places if it was corroded and the mechanic just used brute force to try and adjust it. Especially if the car has ever been on snow covered roads that were salted.

Though no one has ever reported this mishap before on installation of the headlight package and it is hard for me to tell from 6000 miles away. But it likely is related to something in that area as this was the last thing you had worked on.

Luis de Prat

Thanks for the follow up. I've told them to check the tension on the accessory belt. I bet that's it, because the hesitation went away for days after tightening the alternator bolt and it just came back now. Proper tension was probably lost during the alternator manipulation at install. I'm hoping this is it. Thanks again!

83na944

Luis,

Check the fuel insjection boot for tears. Especially around the hose that ventilates the timimg belt cover. I don't see how a loose alternator bolt would cause a problem only on acceleration.

Good Luck.

IceShark

The other thing is a loose air intake hose clamp or vacuum line in the area. Those can get forgotten fairly easy in the rush to button things back up. Since this is on your S2 you don't have the boost pressure blowing hoses off, so it may have taken a few days for things to work loose.

I'd be happy to jet over and take a look at the car if you want to send me a ticket.


Edit: Ah, I see Steve thought about this also. Great minds think alike.

Luis de Prat

On the S2, the timing belt cover hose fitting is open, with no hose. Another S2:



My S2:

IceShark

Removing that hose and blocking off the fittings was in an earlier technical service bulletin and that shouldn't be it. On the 951s that hose connected to the clean side of the air filter box so belt dust and everything else would get sucked into the engine. Metered, as it is before the barn door but who wants to suck crud into the engine. I don't know how the S2 is set up but I would block that off with a cap. However, I don't think that is your current problem.

Luis de Prat

OK, we're checking all the hose clamps and I just instructed my father over the phone on how to change the DME relay. He's a world renowned scientist, but somehow this was a bit tedious for him. At any rate, I want to reiterate that I'm not associating the headlight upgrade itself with this problem, just fishing for possible causes for this problem among the items related to the installation process.

My biggest fear, which would be too much of a coincidence after having removed the airflow sensor, etc., is that perhaps the T-belt is skipping, but the problem seems electrical in nature and I had the whole timing/balance rollers/sprockets pump job done only 22K ago.

Thanks again for your help!