Car stalls. Mystery unsolved...

[blacknight]

On my previous posts, I had mentioned that the car stopped on two occasions. the symptoms were driving along, then complete engine shutdown. absolutely NO WARNING. The power steering would go out, the brakes would fade and the car wouldnt respond to throttle. This is absolutely dangerous especially if if i negotiating a roundabout or in the fast lane. I had practically given up driving the car as it would cut out without warning. And after two trips to the agent, this was done to the car.

1. CAS sensor checked and replaced. It wasnt the sensor overheating or cracked, or the wiring grounding out on the engine block. I was told to splash cold water on it if it stalled, I did it the second time it stalled and nothing happened. no error codes brought up.
2. DFI module changed (TWICE), the DFI wiring harness was checked with a homemade test 'wire' and all wires register current, pins and connectors not flat and connections dry and tight
3. Spark plug leads all new, spark plugs not cracked, grounding wires all tight and not shorting out. Ignition leads all new. Alternator checked and brushes still good. Alternator connections all tight and no corrosion.
4. Battery tested (14.4V) connections had no corrosion. Relays changed (even if it was in good condition), fuses checked.
5. Vacuum hose replaced (one was cracked). I used heat resistant silicone tubing with a stainless steel braid and locked both ends tight
6. Throttle body cleaned, IAC cleaned, MAF sensor cleaned, air filter is new, air intake throat is not blocked
7. Fuel pump is new. Fuel pressure tested (now three times) it registers a good reading on the fuel regulator at all RPMs. Fuel filter changed, fuel line changed (the fiber one). the car always ran on RON98 from a new gas station
8. The wiring loom was 'massaged' when the car was idling, as i was trying to simulate the car stalling if it was an intermittent connection in the wires. Car ran well, even after tapping and shaking wires gently
9. Looked at the throttle cable, it was normal and not loose. No loose connections.
10. The car didnt overheat. the air conditioning, either off or on doesnt make a difference to stalling the car. engine and other fluids at normal levels.

I took the car out from the care of the Agent about 4 days ago, tried driving it around the neighbourhood but not on the highway in case the car stalls again. Brought it up to full operating temps, and cruised up and down the street for 2 hours. early morning, evening and under the hot afternoon sun to simulate all kinds of driving conditions.

spending close to about $1200 to check, fix and replace almost everything and the car havent stalled. It sure would be interesting to know what was the single factor causing it to stall. but at the back of my head, this was a demerit in my otherwise perfect VX. If only cars could talk...

[alpine-wolf]

One other thing which might be a cause, don't know if anyone has suggested, try getting your silver contact ring around the ignition replaced as this contacts the transponder inside the key.
I have heard that if this is getting high resistance that the car is likely to stall as the immobilser circuit comes on when the key loses contact.

[blacknight]

I had the ignition barrel changed less than a year ago (i think) as the die cast metal part broke to pieces. i went to check the contact points on the key and its making good contact. thanks for this new option to check. the battery in the key is new as well and i can engage all the locks and deadbolt it from 5 to 7m away.

[bones308]

i hear you blacknight
i have the same problem for over a six weeks now, i've changed all the same things as you and more the only part i haven't changed is the fuel pump (which is only four years old)
but thats next on the list ,$1000 later and she still stalls,i really don't want to sell her (brought in 1999) but if i can't drive her she's going!!!!!!!!!!!!

[GKW]

Check the outer cover of the plug going into the MAF.

Had something similar a while back. Turned out the plug going to into the MAF was slightly damaged from someone putting it back on carelessly and as a result, was causing the car to stall for no apparent reason. Thankfully that was an easy fix which my mechanic id'ed quickly.

[Huntington]

noticed neither of you mentioned replacing fuel pump relay. have seen them die before, which will cause sudden stalling. and the they usually come good pretty quick allowing for the car to restart. only to stall again later.

they are cheap, so it it should be one of the first things you check. hate to spend a fortune to find its something as simple as a $20 relay.

[bones308]

fuel pump relay changed as all relays plus fuses.

no error code recorded???

[blacknight]

The fuel pump relay, starter relay and all other relays were swapped out for new ones and still no difference. I'm positive it isnt the pump, bad fuel, the fuel injectors, clogged up ports, the fuel rails, the fuel pump solenoid as this pump is less than two years old. Was tested 3 times at the agent and the pump still delivered very healthy amounts of fuel at all RPMs from idle to 5K on the RPM. From my own experience with a fuel pump thats going to 'die', it will give you a few days warning by giving flat spots, no power at the throttle and uneven surge of power. I'm positive its not fuel or pump related. maybe a combination of electrical gremlins or something mechanical which MAY have been contributing to its sudden stalling.

I just wished i had been able to pinpoint what was the single cause. still not 100% confident in driving it and that is a shame

[alpine-wolf]

Another possibilty could be the ECU, may have fried a couple of components?
About 4 yrs back when I had a Mitsi the Ecu got fried after jump starting without spike protected leads and it still ran, not very well though. Lots of problems with engine stalls etc.

[blacknight]

yes, the wires leading up to the ECU were all dry and cant see any sign of moisture intrusion. in the tropics here, it gets really hot and i'll admit this is something i havent seen (the inside of the ECU)

Maybe there's some corrosion inside??

[alpine-wolf]

I would be thinking more along the lines of "dry" solder joints or possible damaged components which after warming up, fail.
In the Mitzi I had there were several capacitors which had been "cooked" with the power spike from the jump start and 1 of the IC chips damaged from memory.

[blacknight]

there wasnt any aftermarket or new repairs to the wiring looms, and i think 'bad soldering joints would be giving intermittant connections. Never jumped start anyone's car in the hostory of the VX as i heard there massive voltage spikes in the system. your idea of bad soldering joints is something i'll look into

[VTS5]

It sure would be interesting to know what was the single factor causing it to stall. but at the back of my head, this was a demerit in my otherwise perfect VX. If only cars could talk...

Did you changed one item at a time or the whole lot? Did you test after each item replacement? Sounds very much like CAS.

[VTS5]

Check the outer cover of the plug going into the MAF.

Had something similar a while back. Turned out the plug going to into the MAF was slightly damaged from someone putting it back on carelessly and as a result, was causing the car to stall for no apparent reason. Thankfully that was an easy fix which my mechanic id'ed quickly.

Engine would start and run very very badly but never stalls even if the MAF plug not plugged in.

[blacknight]

The CAS was the first thing I changed. I knew about the 'pouring cold water' quick fix but it still didnt restart. just cranking over...
When it was a new CAS sensor, the car still didint turn over. The wiring loom checked, nothing grounding out on the sensor, all things good. Then i moved on to other areas and eventually replaced what you see on my list.

[CIRCLEWORK]

i feel ya i have the same problem but it hasnt done it in a while it happend twice to me i took it to my mechanic and cant find shit wrong with it no fault codes no nothing