Ok people my car is not playing ball..Anyone got any ideas?

Car..1997 VT 5ltr 68,000ks (HBD) Auto, Extractors, high flow cats and mufflers, twin 2 1/2 to diff then 3 inch to rear box.
Exhaust is only 2000k old.

Problem..

Ok a few weeks ago out of the blue my 5Ltr VT started surging like someone was turning the key off and on. At the same time the engine light was going on and off..When I came to a stop the car stalled and after waiting 10 minutes I managed to get it to fire and limped to my local mechanic. I had a guy follow me just incase I didnt make it and he told me the car was belching smoke out the back..So I presumed it might have been a fuel problem..
After it sat 10 minutes at the mechanics it started and ran fine for 5 minutes then just stopped..So fired it up again it ran for a while then stopped..

We then hooked up the computer and it came up with nothing out of the ordinary..No fault codes and everything as it should be only thing out of the ordinary was a occasional voltage spike..and it would just stop for no reason..

So thinking it was a problem with the electrical side, we put on a new coil, Replaced the crank angle pickup in the dizzy, New distributor cap and leads..Fired it up and took it for a spin only to have it stall and not refire..So a tow back to the workshop..On inspection found the new coil had s*** itself so thinking back to the votage spike before hand, we replaced the inbuilt regulator in the alternator and fitted new spark plugs even though the old ones had less than 5000ks on them..

It would fire and run without stalling but sometimes at idle it would start running on 7 cylinders then eight..wether its hot or cold..The thottle response is about as good as a worn out v6. It used to be nice and crisp and pull like a good 5ltr should..sigh!..It has a bit of a stumble at 1500rpm sometimes, and has a surging feeling at 4000rpm.........

I have taken it back to the workshop and put the computer back on it..it comes up with no problems all the readings are fine and both sensors on the exhaust are working in the normal range..
The timing has been rechecked and we sprayed all around the inlet manifold ect with some spray and checking hoses looking for a vacume leak..and found nothing..

I forgot to mention that the fuel filter was replaced and fuel pressure was tested..and it has had 3 lots of injector cleaner throught the car since I bought it 4 months ago.
The reason for the injector cleaner was the last owner bought the car in 2002 and only drove in 25.000ks..It spent most of its time sitting in the shed..(Just wanted to make sure no fuel had gone off in the rails ect)

Ok Hedging my bets I had the local mechanic hook up the computer and do a test again..Now code 49 shows up..... Cam / Crank Shaft Signal Intermittent.
So I drove it around to the Holden Dealership and hooked up their tester..and did a full test including injectors ect..code 49 is still there and refuses to clear.
The Holden dealer tells me that code 49 means there is a wiring problem between the distributor and the comp..They printed out a "How to check and repair" from the Holden Manual for me to pick up.
Checked over the entire wiring system and cleaned every connector and took the car back..but code 49 still showed up..
Now get this, we have replaced The distributor, Trigger box, Computer with new items and the code is still there..It seems there is a pulsing problem with the crank angle sensor...Coil has been checked (Its new anyway)..Brian at the Holden dealership even wrapped the wiring in tin foil to see if it was interferance..still the problem persists although now if you clear the code and the car is idiling it remains code free but as soon as you increase the revs to about 1500 it throws the code again...

My hat goes of to the guys at the dealership who have bent over backwards to find the problem.
They have gone out of there way to help me..Phone calls to GMH tech support..even trolling the net after hours on forums like this one trying to find answers...Checking and rechecking..Well done guys!
So now its been in the shop for three weeks and everyone is still no wiser..

Anyone out there ever come across this problem before?



One more thing that I didnt know..When the car throws this code (49)the injection goes into limp mode so it changes from sequential injection to pulse..In otherwords the injectors all fire at the same time every revolution of the crank...This explains my 5ltrs V6 performance...lol

Cheers!




"We are but a grain of sand on the beach of life"

That happened to my mate ,it was the computer..ECU Module ,now fixed.

Jim in Adelaide..