Nahpets

Hello!

This topic is somewhat long, but please bear with me:

I was driving 500 kilometre back home when I experienced my engine dying several times. As I was cruising the highway the car jumpstarted after between 1 to 5 seconds. THe engine stopped no matter speed, gear or de/accelaration. THis behaviour repeated for 10 times during 200 kilometre.

One time the engine stopped as I was slowing down, forcing me to stop the car as the engine didnt wake up. I tried to start the engine ordinary way using the key, but after 5 attempts nothing happened.
I then went out and played with the Throttle Position Sensor and Air Flow Sensor. Then the car cranked. After this exercise I could go 300 km with only two "jerks". FInally reached the garage.

Now ... the engine died again when taking a spin another day. I jumped the DME relay but the car didnt start anyway. So that would put a faulty relay out of the pic. As I jumped the relay I saw the FPR jerk and heared the humming noise from the fuel pump. So I assume the fuel is coming as it should.
As before I disconnected the AFS connector and plugged it in. First start attempt no action, I repeated the exercise and this time the car started.
As the car idled I removed the AFS connector and it died. As I plugged it in, I could start it again.

Could it be a faulty AFS connector/circuit?
What items could be causing erratic sudden stop of the engine assuming the fuel delivery is proper? Spark plugs (how do I check if there are sparks?), bad ignition coil ... so on
Or is there another reason for this erratic engine stops?
Someone with similar experiences?

Kind regards
Stephan

SprintStar

I had a similar problem. Next time it happens. Try see if you have spark, that will rule out ignition and a LOT of things. It means your speed and ref sensors are ok, etc...

I think my problem is the DME. I am waiting for a spare DME/KLR to arrive.

My car will die and for the next 20 mins, nothing can revive it. Leave it for a few days, he will be ok. I suspect the injector driver.

Oh well, we will know soon.

Sprint.

Nahpets

Hi Sprint,

I have tried jumping the DME relay according to Clarks Garage. But the car wouldnt start anyway.

How do I easiest check if I have spark? Do I just remove one spark plug and with the ignition cable mounted see if there is a spark between the electrodes?

I hope the DME is not the culprit ...

Cheers
Stephan

ehall

If it happens again, after attempting to start it with the key, get aout and wiggle the speed and reference snsors. Get back in and see if it starts. If so, you'll know that the sensors are out of alignment.

CPR

I had the same problem...reference sensor was not properly fitted (depth incorrect). This was after 2 weeks of changing everything else...@#$%

bigdeano

+1 on speed and reference sensors. The things always seem to be the cause of this kind of problem.

Nahpets

Thank you very much for the input!

I will have a look at the sensors and write what happens.

Cheers
Stephan

Papamurphdog

Tell me about injector drivers please. Can anyone elaborate on this. I had/have similar issues from time to time -- see old string -- and it gets spark as I can use starter fluid in the intake and it "runs" but dies as soon as the starter fluid is used up -- injectors not firing most likely. You may remember the string where I had to jump the alarm system and DME to fix it, but id really like to know more about what can prevent the injectors from firing; sure many would... ehall??? Ideas??

SprintStar

Hello Stephan!

Yes, I tried jumping the DME relay and I can't start either. And I've verified I've to the fuel pumping pumping.

To check spark, what I do is to remove the lead to the cap from the coil. Place it close to metal and it will jump the gap. I suggest carrying a spare spark plug (obviously one known to be good) and plug it in when this happens. See if it will spark.

If so, you definitely have ignition and therefore I think the speed and ref sensors are fine. I don't think alignment is an issue since you still get a spark. Can someone chime in? I'm having the same problem and I'm hoping to fix it good.

A side note. I think UPS is crazy. I bought a spare DME and the shipper mistakenly sent out via UPS Expedited instead of UPS Saver. The irony is Saver cost only $6 more and they guarantee delivery in 3 days whereas Expedited takes 7 days! I'm so pissed!

Sprint.

Nahpets

Hi everyone!

Thank you Sprint for your comments!

Today I went for the speed and reference sensors; I disconnected the cable connectors and reconnected them again. Also checked that the bracket where the sensors are mounted on was fastened and so it was. I also measured the resistance values according to Clarks Garage = conformed.
But I found something: Please see link: http://www.arnnworx.com/sensor_tool.htm . See the pictures on the bottom. What sensor is the third one (oval one)?? I dont have it!

After this execise I went out for a spin. This time after 15 minutes of running the car came to a complete stop. Dead!
As I turn the ignition switch, the start motor runs but the engine never comes into play!
Suspected that there were problems with the spark. So I took one spark plug and connected it to the ignition coil cable and put the plug steel housing onto a metal part on the engine: no spark!

What does this mean? What components might lead to spark failure.
Cheers
Stephan

gregeast

I had similar symptoms and it turned out to be a bad solder joint on the DME board. If I banged on the DME it would start working again and then intermittently fail. I was able to resolder a transistor on the board which is the ignition coil driver. No spark = No Go. Happy to report that all is well 2+ years later.

See my DME Repair thread for a detailed write-up with pictures.

Hope this helps!

Cory9584

You NEED to check for spark. Next time it does it pull one of your wires and stick a screwdriver in the boot, then place the screwdriver close to something metal and crank it. If that's ok the next step is to check for fuel pressure.

IanM

I had a similar problem. My car would die sporadically, especially if it was hot outside. Ended up being a short in my engine wiring harness. I never did find the short, replaced the harness.

blown 944

Generally it is the reference sensors/ adjustment or the connectors. The connectors can become corroded and any bad connection causes this. It usually happens on ah ot day or after the car has been up to temp for a time.

Is the Tach bouncing when you are cranking it??

Nahpets

Hi!

No there is not bouncing.
Does this mean the speed/reference sensors are out of alignment/bad circuit?

Cheers
Stephan