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View Full Version : More no start and misfire woes... another thread



SS92
10-22-2011, 09:45 PM
Car is a 2000 Audi A4 1.8T. Don't have an ICM, they are the revised coil packs. Just to start the thread off and rule those out...

TL;DR Car misfired on cylinders 1,3,4 shut car off wouldn't turn back over, towed home, pulled fuel pump fuse and car turns over briefly.

So, driving home tonight on the highway, I start to misfire. Pull over, turn the car off, scan for codes with my OBD. Get random multiple misfire, a well as misses on cylinders 1,3,4. Thought I flooded it when trying to crank it over after to see if misfire would come back when it didn't, so called AAA and got a tow home. I pulled the fuel pump fuse for fun and the car turned right over (and died of course). What do you all think it could be??

I could check for spark in the morning on the coil pack(s), if someone would be kind enough as to let me know how. I know it involves cramming a screwdriver in it and watching for spark... should it spark arc on the top of the valve cover?

Anything else I can check? Seems like I'm just getting no spray or something. Not sure what would cause all three to misfire at once.

I scanned with vag, not a single code. I don't get it. Just the misfires, I cleared but cant get the car to turn over since.

This car is busting my balls lately. [headbang]

walky_talky20
10-22-2011, 10:26 PM
So you aren't mentioning any suspicions of the starter motor, so I'm guessing the engine "turns over" just fine, it just won't "fire". In other words it cranks (and cranks, and cranks) *beautifully*, but no combustion, right?

If removing the fuel pump fuse is helping, it would seem that it is definitely getting flooded. Instead of doing that, you can just disable the injectors temporarily by cranking the car with the accel pedal at WOT. That is a "clear flood mode" so no additional fuel will be added to the combustion chamber. Same effect as disabling the fuel pump. But after it sounds like it is trying to fire you can let off the pedal, restoring fuel delivery, and you might have some better luck getting it started.

I don't know the history of the problems, but misfires on 3 cylinders would lean towards it being a mixture problem, not ignition. But I did have all 4 of my push-down coils fail inside 1 weekend before, so you never know. You can certainly check spark pretty easy. Pull a coil pack, plug it back in, and shove a screwdriver up the end. Position it so the shaft is about 1/8" away from a part of the valve cover. The spark should easily jump the gap during cranking with a nice blue spark. Seeing as yours is not throwing codes for cylinder 2 ever, you can swap 1+2 and see if the codes follow. That might tell you something. Again, it seems unlikely that it's a spark problem, though. More likely a MAF, fuel pump, or something. How old is the Coolant Temp Sensor?

SS92
10-22-2011, 10:45 PM
Yes, it cranks beautifully Walky. I had tried doing the pedal to the floor method with no luck while I was on the highway before I was towed, and at home a little bit ago, it just sputters for a split second then stops altogether but turns over for 2-3 seconds when the relay fuse is pulled. The CTS was replaced just a few days ago with the VW CTS (Same part number from etka on ECS) and gave me no problems for the past few days. I had been driving all over today before the problems started tonight, any reason a mixture problem would be like that out of nowhere? Was just cruising on highway home. I also listened for the fuel pump prime, its priming, can hear it so I know its not totally dead I guess.

I'll check for spark, and swap a few coil packs.

nam3
10-23-2011, 08:35 AM
If your coilpax are good, and spark plugs are fine, then check the coil pack grounds, should b like 3 in total, all brown wires.

Also you might want to check like o2 wires, see if they are brittle exposed and contacting.

B5RiceEater
10-23-2011, 09:10 PM
Buy an inline spark tester its like 25 bucks with noid lighrs to check fuel inector pulse at eppys.com set aside from that, whens the last time u changed your coilpacks/spark plugs? Buy a compression tester also you can buy 1 for about 100 bucks or less

B5RiceEater
10-23-2011, 09:12 PM
Disconnect a fuel line temporarily turn the key on for a second and switch it off if fuel is spewing out u have fuel pressure ...u basically have all the knowledge right there to figure out your problem

SS92
10-23-2011, 09:25 PM
Turned out to be a crack in harness wiring so I taped them up for now and two bad coilpacks that I replaced with old spares. Spilled fuel everywhere after checking for spark. Think my pump is on its way out as well though, so looking for some options on that.

I've been meaning to check the health of the engine with a compression tester. Anyone know a cheap one that I can use on multiple engines? Also, noticed my plugs are almost gassed already. I have a tune from 034 for my gt28 elim, as well as the supporting mods. Should I be getting a colder plug, like the bkr7e's? Not sure what to get, 034 doesn't say and all the mods are second hand from previous owner.

Thanks for all the help and replies. This car is a nightmare.