help with dd! weak spark on #1 and #3

[pearl4gtsi]

so i have searched this issue and the threads ive found have no conclusion.

lets start from the beginning. last thursday i replaced my alternator. regulator went bad. drove to school, drove to my cousins. car sat for a couple hours. when i went to go home, i noticed my a/f gauge wasnt working. and noticed a miss/stutter on warm up. the drive home was fine.

was worse the next day, so i figured my o2 went. bought a new one and replaced it saturday. car still ran the same way. found a bit of oil in spark plug galley on #2 cylinder. cleaned it out and went for a drive. took a little bit but it cleared up and the car ran great.

next day, constant stutter! would not clear up and it seemed to get worse as it warmed up. checked my plugs, regapped them. ohmed out my plug wires and they r good. still same problem.

so i decided to test out my power transistor. according to my chiltons manual, it was no good. picked one up from a friends part out(running car, keep in mind). decided to test it out and got the same result as the one out of my car. but i figure it came out of a car that ran very well, so i put it in. same problem.

picked up a the coils off the same runnning car. swapped mine out, and still same problem.

decided to pull and check my ecu. opened it up and found some cap leakage on the board. cool i thought, theres my problem. swapped it with a very clean spare that i have..... and STILL same problem.

also decided to check my injectors too as ive had to replace my resistor pack recently. all injectors working and sound good. but even tried swapping in another resistor pack. nothing.

the only thing i havent tried yet is the CAS. although im weary because in the other posts ive read, these guys are throwing the same parts at the car with the same problem and nothing seems to be fixing it.

also checked my grounds from IM to firewall, from neg batt terminal to firewall, and the ground on the starter bolt. all good and tight, all clean.

it is my dd and causing a big inconvenience for me to get around to work and school. any body have this problem before and ACTUALLY fix it? i could soo use the help.

 

[92AWDHX40]

Spark comes from coil pack check , or change that.

 

[pearl4gtsi]

i did check the coil pack. forgot to mention before. i ohmed it out as per chiltons and the both i have test out good.

what throws me off is that my issue is with cylinder 1 and 3. 1 and 4 are paired, and 2 and 3 are paired. so why am i having a problem with 1 and 3?? there not really "on the same ciruit" so to speak.

also, i remeber reading a thread where this guy had a mis/stutter problem and changed his alternator and it went away. doenst really sound possible, but maybe its worth a shot to throw the old one back in and see what happens??

 

[92AWDHX40]

Never rule anything out, even new parts, i found can be bad, check everything.

 

[pearl4gtsi]

do you think maybe it could be a knock sensor? just thinking outside the box here. i have spark, but its weak. something is obviously causing it. ive heard of people hitting knock at idle..... possibly the sensor is bad and showing knock so the ecu is pulling timing??

i have a palm and mmcd but its not working. i have to get it running so i can check to see if im getting knock.


im also going to check base timing and ignition timing tomorrow. along with a compression test. yeah, good idea

 

[DSM_IKE]

Sounds like an issue ive been having every once in a while. Only when my car is cold and warming up it will cut out on two cylinders and will shutter. I have yet to try this just because i havent had the time, but someone else told me that its possible that the icm (ignition control module) might be going bad. Its on the drivers side right under the intake, has two 10mm bolts holding the bracket on. Sounds legit to me so as soon as i get the money and time im going to see if thats my problem.

 

[pearl4gtsi]

icm, power transistor...... tomatoe, tomaato. replaced it with one from a good running car as previously stated.

 

[And_44]

Hehe, think you may of read my post. I had identical issue. 1 and 3 having weak/no spark.

Have you switched wires 1 and 3 to 2 and 4 and see if they follow the posts of the coil. Electricity will follow the shortest path to ground(spark plug). With the way our coils are designed with the power input behind one post and not in between it seems to work like that when not enough juice is flowing to module/coil.

And you said that you put in a new alternator, there are loads of posts of people getting bad alternators right from box. These regulators probaly have Made in China on them as they probally stopped making them in Japan a while ago. The alternator may test good cold as do most electronics do, but testing the output with it hot and malfunctioning would be hard because of the fluctuating idle. If your buddies alternator worked fine grab his and try it out.

ALSO, did you purchase the right voltage alternator from parts store? They have 2-3 different voltages and if you got a lowbie it just won't do it's job.

 

[pearl4gtsi]

yeah i deff read your post. did you ever fix it?

i will try swapping around the wires, by chance it makes a difference.

i will see if my friend still has his alternator. if not i have my old one. even though the voltage reg. wasnt great on it, if i swap it and the problem goes away...... but wont know until i try.

i did get the 90 amp alternator. i have a small sound system in the car( one of those infinity basslink thingys) plus having the fuel pump hard wired, i figured the higher amperage would be better.

any thoughts on possibly a bad knock sensor showing knock at idle?? i mean, mine is over two years old, and they are not that expensive. might as well change it anyways

 

[And_44]

Yea, a new alternator fixed my issue. But these alt's from Schucks/O'riellies, or autozone have a bad rep for being bad from box.

And save your time on putting in old alt if it was bad don't waste the time.

But your knock at idle maybe from the misfire.

Your CAS tells the ecu when to fire the fuel injectors.

Try to disconnect the wires for the sound system to remove that draw and see if it improves.

 

[pearl4gtsi]

ok, so after work i jumped right on the car. swapped my alternator, just for kicks. no fix

checked my compression 190 across the board. checked base timing and ignition timing, both spot on.

noticed when i pull the wires off of 1 and 3 while running, the wires arc by the coil to the IM.

decided to pull each wire individually while the car was running to see how the motor reacts. 1-3 made a difference in the way the enigine ran but 4 didnt. so i pull the plug and it was soaked. wasnt like that the last time i checked, id remember that.

so along comes my dad and suggests swapping the #4 plug with another and see if the problem moves with the plug. and sure enough it did. the spark plug was bad. in all my years of working on cars, i have NEVER seen a spark plug not fire unless it was BAD. but the plug was intact and gapped properly, just would not fire.

so i swapped in a new set of plugs and its smooth cruisin. thnx again to you all for your help and suggestions.

 

[standard235]

Gotta love chasing your tail on a $8 fix.

 

[pearl4gtsi]

. your telling me.

 

[zackharkness]

I realize this thread is a bit old, but I'm looking into getting a 96 TSI AWD with a 6 bolt swap that's having the same issue. Accept from what the guy tells me the car idles decent, and drives around the block fine as long as you stay out of boost. But as soon as you get to about 1 PSI it blows clouds of black smoke and sputters real bad for a bit. Just wondering if this is in line with the issues you were having.

 

[pearl4gtsi]

Zach.... I don't recall my car blowing any smoke when this happened.... It was more of a dead cylinder then a sputter....

You might be looking at very weak spark or running WAY to rich.... I would deff check spark plugs... And check the tune.