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Discussion Starter · #1 ·
Just curious. How long do ignition wires typically keep going? Mine have lasted about 116K (on a 91L that I bought new). But now I'm getting a rough idle and there is some indication that the #4 cylinder isn't up to full snuff. I got some weird resistance readings on the #4 ignition wire (admittedly using an inexpensive ohm meter) and when I pull the wire while the car is idling there doesn't seem to any difference in the idle (there's some difference, but not a heck of a lot, when I pull either of the other two wires on the front head).

What'ya think? Time to invest in a new ignition wire set or should I pursue other possibilities (whatever they are) first?

BTW, I just installed a new timing belt, tensioner serpentine belt, etc, plus a new water pump. Now I'm getting a coolant leak from somewhere in the neighborhood of the new pump. I have to go back in and check everything.

Arrrghhh!!!

Mac D
 

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Discussion Starter · #2 ·
An addition to the above post:

After sitting overnight I started her up and the miss is now consistent in all speeds, not just idle.

I also noticed something else which I'll describe in a separate thread (see "T Belt Tensioner."
 

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116k is not a lot on the OEM wires. How old are the spark plugs and have you cleaned the fuel injector connector on the effected cylinder?
Charles
 

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Discussion Starter · #4 ·
The plugs are new. I checked the electrical operation of the #4 injector by listening with a listening tube; I could hear the injector clicking away nicely. The funny thing is, when I first started her up this morning the idle was smooth and then roughened up a bit after a minute or two. This is the same thing that had been happening prior to the current work I'm doing on the car -- she'd be smooth at start-up then get a bit rough at idle. Also, after returning to the car following a brief stop in a store, etc., the idle would often be temporarily smooth and then roughen up again.

BTW, I switched the plugs around before this latest test and there was considerably less roughness than noted in my previous post. Also, it was hard to tell if there was any misfire at higher rpm's -- unlike the original test.

The other thing to consider is the funny ohm reading I get through the #4 plug wire.

And now, for something completely different... I've installed a new serpentine belt and idler pulley. The pulley sings if the belt is too tight; the belt squeals if it's too loose. I haven't been able to find a happy middle ground that suits them both. Should I lean toward singing or toward squealing?

Mac D.

Mac D.
 

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What kind of belt are you using? The Dayco belts with the solid ribs need to run tighter so they don't squeal. The Gates belts that have the broken ribs grip better and don't need to run as tight. I think your find a happy medium withe Gates belt.
 

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What kind (brand and model) plugs are in it? I put the recommended (by their guide) NGKs in mine and found out they were not the right heat range and it idled rough immediately. Went with Champion 415 plugs and it smoothed right out. Don't laugh at the Champions, they work great in this engine and some came with them originally. Also, you may want to pull all the plug wires and give them a good visual inspection as well. If one of them has a split or any damage, you will want to get a new set. The OEM wires last a long, long time though and no need to replace them until they are truly done. Some aftermarket ones do not fit correctly either, so you have to be careful with what you get.
Charles
 

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Another thing to try...On a very dark night, look at the wires with the engine running. It helps to throw a blanket over the hood and your head to block any light. Look for arcing.
 

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Discussion Starter · #8 ·
I am using the Champion 415's. I'll double check the #4 plug wire and give it another resistance test.

As for your suggestion, Richard, about avoiding the Dayco serpentine belt: I got both the belt and the pulley from Alfissimo. I believe the belt is, in fact, Dayco. Are you saying I should toss it?
 

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The Dayco belts work fine. You just have to tighten them enough so they don't squeal. The Gates belts don't seem to be as touchy. They grip with less tension.
 

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Discussion Starter · #10 ·
My problem is that when I tighten the belt enough to stop the squealing the new pulley makes noise. I haven't found a midway tension that satisfies both. Is the singing of the pulley something that goes away as it breaks in? (I didn't have this problem the last time I changed the belt and pulley. I don't think so, anyway. But then it's been a while.)
 

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Is the new pulley packed with with Jason's special grease? I'm surprised the new pulley is noisy. I suggest you email Jason and see what he suggests.
 

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Discussion Starter · #12 ·
I just sent Jason a message regarding the pulley. Hopefully he'll have a solution. Thanks.

Meanwhile, I still have the misfire to sort out. I'm tempted to bite the bullet and order a new plug wire set. On the other hand, while the #4 injector sounds like its electronics are working properly, could the nozzle be clogged or impaired somehow thus creating the problem? How would I check for such? (The injectors were last tested by an Alfa shop about 27K ago.)
 

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Not sure how much checking an Alfa "shop" can do on injectors. I took mine to a diesel shop that services Bosch injectors. They were cleaned and checked for spray pattern. I doubt if the normal Alfa "shop" would have the equipment to do this. I've also run injector cleaner through on a couple tanks of gas with some improvement. The Chevron cleaner is one of the better ones.
If you got a bad reading on #4 wire, and want to check it further, I would go to an auto supply shop and buy 1 cheap wire to replace #4. If it solves your problem, spring for a whole set. What are they now...$200?
 

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Discussion Starter · #14 ·
Too late to check the wire. I just ordered a new wire set from Jason. It's only money, right? (Or money down the drain.) If that doesn't work I'll have to focus on the injector. Or here's a thought... Since the engine is relatively smooth at start-up, could it be that enough oil has collected in the cylinder to compensate for a problem with the rings, etc., and once the oil burns off there's less compression and less power coming out of that cylinder? Or is my imagination getting out of hand?
 

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Rough idle can also be caused by unmeasured air getting into the system. Air measurement is done by the flapper in the air cleaner housing, so you could check everything down stream of that. Checked for cracks in the big black air hose (carefully check the bellows and 2 small connections for the idle actuator and oil separator), check the fit of the idle actuator into the air box and the hose, check the 3 hoses off the oil separator. Those are all favorite places for leaks.
 

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Remove the IAC from the back of the intake manifold, clean the inside of it with throttle body spray cleaner. Wrap some electrical tape around the rubber donut gasket to make a tight fit with the hole in the back of the intake. All to make sure the IAC is not sticking and you have no false air leaks with the manifold. That one is a tough leak to find if you don't know about it. I would replace the coolant temp sensor (the one for the ECU, not the gauge) at the thermostat housing too, they cost under $25. I wouldn't even test it if yours is original. It's nice to know you have a fresh one in there after 100,000 miles. Of course number 4 cylinder still needs sorted, but you will narrow that down with persistence.
Charles
 

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"Is the new pulley packed with with Jason's special grease? I'm surprised the new pulley is noisy"

They all make a slight noise it seems. I have one of the Krytox lubed ones with about 50k miles on it and it makes a slight noise, using a rubber tube to listen with; however, I also have a completely stock one with less than 5k miles on it, and it sounds exactly the same when installed in a comparison test, same car, same day. Just slightly noisy, but both are absolutely completely smooth in feel.
 

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I have noticed when you use a plastic pulley tensioner (like the Saab pulley), it sounds quieter than the metal OEM ones. The rubber rubs on the metal (since there always is some side to side movement of the belt on the pulley) and makes a bit of noise. Not much you can do about it.
Charles
 

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Also be sure piulley is not rubbing/wearing on inner fender liner and grinding liner and making extra noise there.
 

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Discussion Starter · #20 ·
It's hard to tell if the pulley is plastic or metal. But the noise is not coming from the pulley rim, it's coming from the bearing. I pin-pointed the source via a listening tube. There's no rubbing with the fender liner because the liner is off while the car is up on a jack during testing. Just for comparison, I reinstalled my old (metal) pulley and it is much quieter than the new unit. So what to do?
Keep the old unit on until it screeches its imminent demise or put on the new pulley and see if it works itself into a quieter mode?
 
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