matt_e30

My '93 90q died while I was driving to work this morning. I was coasting up to a lights and it just shut off. It was charging fine before it died and it cranked over just fine after it died but didn't fire. I think this eliminates alternator or battery.

That leaves fuel or ignition. I know the fuel pumps are notorious for dying but I think the car would have sputtered rather than dying completely.

I am currently thinking it would either be the ECM or possibly the coil. However I don't know much about these audi's. Where is the ECM located on my car?

I know I can pull the plugs to check for spark, but assuming I don't have spark how can I determine whether the coil or the ECM is the issue? Any way to test the coil?

Thanks in advance for any knowledge you can pass my way.

Lago Blue

Can you hear your fuel pump do it's one second priming routine when you turn the key to the middle position?

Check to see if there are any saved DTCs.

Use a 7th spark plug inserted into one of your six leads, ground the plug to the engine and see if you have spark while cranking. If you position the plug carefully you may see it from the driver' seat. Partially closing the hood may help.

When I pulled my fuel pump relay, engine died immediately.

ECMs are notoriously reliable. Here are some easier things to check:

You have 3 coils, are they all dead?

My on-board spares also (besides 7th spark plug) include:

Ignition switch;
Fuel pump relay; &
POS.

All are well-known (search-able here) suspects in your case.

The CPS may also cause this, but I have not been there yet.

In the seat-back, I also have the 12v.org DTC list in a little binder. I also should say that in order to erase codes, I have to disconnect the battery before proceeding with the 12v.org procedure (my car is also a 1993 90q).

matt_e30

Where is the fuel pump relay on these cars? Is it in the fuse box? Is there a main relay for the ECM like on my e30?

Also on my e30 when the CPS came unplugged the car wouldn't even turn over. Not sure if the audi is the same .

I have never been able to hear the pump prime from inside the car. It is under a panel in the trunk correct? I will try listening from in there.

Is there a procedure for reading the trouble codes? Can it be done without a scan tool? I will also have a look at that.

SC_09iduA

Here ya go: Start here and if you don't find what tha problem is swap the fuel pump. The fuel cools the pump so when you or if you drive the 90 past a quater tank it jepordizes the life of the fuel pump. Mine didn't ever prime at an audiable level...I switched everything and ended up swapping the fuel pump and BOOM...all's well now. Check your codes with this: http://12v.org/maintenance/dtc.php

Lago Blue

How long have you owned this car?

Do you have an owner's manual? See instructions on how to release rear seat.

Fold down the back seat, then turn the key and listen.

See instructions on where is that main fuse panel anyhow?

Fuel pump relay is exactly as per the panel lid relay label that reads: fuel pump relay.

You may be correct re unplugged CPS, I haven't done that yet.

Your car is OBDI; no scan tool required.

matt_e30

Thanks for all the help thus far guys!

Spent most of the free time I had last night getting the car home, but had a chance to check out a couple of things.

First I used the method above to pull the codes. I even had a little cable in the glove box for jumping the connectors! Anyway the car flashed out the 4444 for no stored codes. The thing I found to be unusual about that was that I pulled the codes with the engine not running obviously and according to the 12v.org write up I should have gotten an engine speed code if it wasn't running. So this makes me think maybe the crank sensor is to blame.

Also I put my ear over the cover plate to the fuel pump and had a listen while the car was cranking. The pump definately primes when the key is turned to "on" and when it is cranking I can hear the pump pulsating.

I am going to investigate spark tonight and look into the CPS and Hall sensor tonight. I will update here with my findings.

maineman

when my car didn't run it flashed a cam position sensor fault.So,the car doesn't need to run to test codes.I believe they recommend it running for codes but not required.
There are test for all those sensors on 12v.org. but since you haven't gotten any stored codes seems a little odd.
Pull your plugs to see if they are wet and to see if there is spark.

Obviously things like

year of car
mileage
type motor
Usa/canada/euro all help in us helping you.

Your right and going through the basics
fuel ,spark,compression.
good luck and report your findings so others can be helped.

good luck

matt_e30

I know the car doesn't need to be running. It just says on 12v.org that you should get an engine speed sensor code if you check them without the engine running which you can then ignore. I had no codes.

Do you have a link for the testing procedures on those sensors? I cannot find it anywhere on 12v.org.

maineman

http://www.12v.org/engine/index.php?...3&comp=g4#list

You need a bentley manual or search the forum for the testing procedures.

Mcstiff

Not to be negative but have you checked the timing belt?