Aeb engine takes way to long to start CEL

[b52400]

(Cold stars)OK so the cel isn't flashing turn key ,turns over but doesn't start until like the the 10th time trying could this be a fuel issue or spark would really like to know before spending money on a fuel pressure test kit ignition coils seem very worn to but once car is up to normal operating temp starts first try .

[b52400]

Bump

[ricekikr]

Need more info. Specs / mods / history.

Have you tried priming it more (key on key off key on key off ...........)?

Could be anything from fuel pump check valve, fp relay, worn pump, start up fuel (tune), crank sensor bad ecu etc etc

[Wrath And Tears]

Long crank usually has to do with the cam or crank position sensor from what I've read.

[b52400]

The car is a 98 a4 quattro its totally stock I just did the timing belt and water pump but I have had this issue before the installation of these parts I have tried the key on and off but still no luck I can hear the fuel pump running and I took the injectors off and seen that thery have moisture coming out of them so I think its getting fuel ...the car cranks over after a lot of cranking the after the car runs and gets up to temp it is a lot easier to start the car was overheating until I changed the water pump I'm also getting milky oil not sure if that's head gasket or just me driving the car so much after the water pump went ...when I did the timing belt I did notice the intake cam wasent dead center on the box given up neer the can chain but it was still in the box however this was happening before water pump and timing after the water pump the car dosent over heat...I also noticed after cranking the car the like the 50th try the oil temp light comes on but that happens rarely.

[walky_talky20]

Hard cold start can point to the mixture being too lean for the given temperature. This could be due to a faulty coolant temp sensor. If it gives a bad reading (warmer than actual temp), then you will not get enough enrichment for a decent cold start. You can confirm by checking the ECU's value of coolant temp and intake air temp before a cold start attempt. Given a long cold soak period, both value should be very near the ambient temperature.

Another thing to test would be spark capability. On an AEB, the original 3-wire coils are pretty reliable. So reliable that they are often original. Due to sheer age, they develop cracks. Each crack reduces output voltage capability. Cold temps make the cracks wider, causing the voltage to drop even further. You may be having very, very weak spark. A band-aid would be reducing the gap on your spark plugs. This reduces the voltage requirement to fire the plug. But the correct fix is to replace the coil packs to get the voltage back up.

If the coils are factory, I would lean toward the second possibility. If they have been replaced at some point, I'd probably lean toward a temp sensor issue. But it would be simple to test and see if either of these problems exist - without replacing any parts. For the first one you use VCDS to check temps in the measuring blocks. For the second one, you get the car really cold, then pull a coil pack, stuff a screwdriver in it and hold it 1/16" away from the valve cover while somebody cranks the engine. Spark should be strong and blue. You should be able to widen the gap up to a 1/4" and still get it to jump. Lousy spark is weak and orange and will not jump very far.

[b52400]

OK thanks man ..and does spark plug need to be in the coilpack or just the screw driver lol sorry Ive done something like this before but not the same engine also the CTS has been replaced with blue top 4 pin

[b52400]

Just kinda seems like something that can give me a bit a shock but I think I get what you mean basically I'm watching the spark jump from the screwdriver to the valve cover ?

[walky_talky20]

Yes.

A common version of this test is to put the spark plug in the end of the coil pack and hold the spark plug to the valve cover. But the screwdriver test gives you more information because you are able to increase the spark gap on-demand during the test to see how much "headroom" you have. You are really trying to ascertain the strength of the coil, here. It practice, it gives you a much better idea of the health of the coil. The test with a spark plug is useful for telling if you have spark or not, but doesn't give you a clear idea of strength.

There exists an actual tool for this, which allows you to choose a specific gap and gives you the approximate voltage that jumping that air gap requires. That way you can have a repeatable gap distance (for example, to find the weakest coil among 4, even if the difference is minor), and actually arrive at a voltage number that the system is capable of (in kilo-volts).

http://www.amazon.com/Lisle-20700-Co...3395207&sr=1-2



I've never used one of those tools. Screwdriver works fine. Tips for not getting shocked:
- if you can get a phillips head screwdriver that clips into the coil nicely, you can then handle the entire assembly by holding onto the top of the coil. This keeps your hands away from the business end of things.
- if you have to hold the screwdriver, do so by the handle (a glove would be nice) and keep the gap reasonable. If it can't jump the gap, it might jump to YOU instead. If the spark scares you, REDUCE the gap. If you pull away, you are increasing the gap - and thus the chances the spark will go through you instead.
- Keep one hand behind your back. If you do get shocked, you don't want your other hand to be touching a ground (like the valve cover). Into your hand and out your elbow is fine, but in your hand out your OTHER hand means the voltage passes through your heart. You want to avoid that.
- Gee, I made this sound scary. It really isn't. Watch some youtube videos. It's not a big deal, but safety first is always good.

[b52400]

OK only really tried on coil cause the battery ended up dieing but seemed to spark fairly well spark was blue for the most part but did come up orange a few times I'll try the rest when I get charge in the battery

[haliceaa4]

I replaced my coolant temp sensor before also and it just failed on me this last week couldn't get the car started would take a half hour and my battery would die replaced it and no issues

[b52400]

OK question were do I get a vcds? Would a obd2 scanner work just the same?

[walky_talky20]

A generic obd2 reader with data stream capability will be able to show you the same coolant temp reading that VCDS would. A lot of the super cheap "code readers" don't do the data stream, though.

VCDS cable is $10, and the software is free. Then just borrow your father/mother/sister/brother/girlfriend/boyfriend/roommate's old Windows XP laptop for an afternoon, and you're golden. If you plan to continue to attempt DIY fixing your Audi when it breaks, this $10 purchase will be more useful than any other tool you could buy at even 10 times the price.

[b52400]

Haven't got the obd2 yet bet have replaced CTS and still no luck .