VT 5Ltr Engine problem..

[GTS308]

I hope I have posted this in the right section..

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.

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 shit 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..

Now it fires and runs without stalling but sometimes at idle it will 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..

So whats next? Do I replace the distributor..ECU..New car..lol
Its really starting to Pi@$ me off....I dont know what to do and neither does my mechanic..

Does anyone have the tuning specs for the 5ltr VT?...Just so I can look over the timing figures and other setting incase we have missed anything!..

Cheers

[GTS308]

Ok bit of a update..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 are printing out a "How to check and repair" from the Holden Manual for me to pick up this morning.
So wish me luck guys in my quest for this problem.....If and when I repair the problem I will post it on here for anyone else who may have the same delema !

Cheers

[50LTRv8]

Hey GTS

Hard Luck man, keep at it though, once you get it goign you shoud be sweet with all that stuff you have replaced

[GTS308]

Well It would seem to me I have the only VT 5ltr In Australia with this problem..lol
My car is still in at the Holden Dealership.

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...I guess the next two steps will be replace the new coil with another new coil and solder every single terminal in the wiring loom..

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!

One more thing that I didnt know..When the car throws this code 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!

[GTS308]

Well the car has been rewired from the control module to the computer and still the code is there.
The car will start and idle code free for as long as you like but as soon as you increase the RPM it throws code 49 (Crank angle sensor intermittent)..

The tacko is fine no short or resistance problem to cause this..the only thing that has not been checked, replaced or tested is the memcal..Never heard of one of them causing problems like this but I guess there is always a first time eh!..The new computer came without a memcal so mine was used and its the only damn thing that I can see that could be the fault..So Monday the new memcal will be here and I hope I can report on here that the problem is solved..If not I may have a very cheap 68000k HBD VT 5ltr paper weight for sale..

Cheers!

[HoldenManDan]

Mate this might seem like a silly question, but have you considered replacing the crank angle sensor?? Perhaps if the sensor is dying it may send an intermittent signal?

Hope this helps

[kniever]

5ltr's dont have a crank angle sensor, instead they have a hall effect sensor which is in the dizzy which he said he has replaced and after that he has also replaced the whole dizzy.

might be faulty ignition module? but im guessing they might have tried that if they have gone thru ignition system

[HoldenManDan]

Mmmm pardon my ignorance then, at least i learnt something

[GTS308]

5ltr's dont have a crank angle sensor, instead they have a hall effect sensor which is in the dizzy which he said he has replaced and after that he has also replaced the whole dizzy.

might be faulty ignition module? but im guessing they might have tried that if they have gone thru ignition system

Hate to burst your bubble there Kniever but the VT 5ltr have both a Crank angle sensor and Cam angle sensor on the same plate in the distributor..
But yes the car has had my original distributor with the new sensors fitted plus another complete new distributor + my own and two other Ignition modules + 2 computers (My own and a new one)

I think maybe 5 ltrs of petrol and some matches may be the only fix....

Cheers!

[kniever]

meh its still a hall effect sensor, people just call it a cas, does basically the same thing plus its also not on the crank

[GTS308]

Yes they are called Hall effect sensors because of the way they work...They are named crank/cam sensors because of their job description..Crank sensor for the timing..Cam sensor for the injection.
Memcal didn't roll up today so spent the whole day checking and rechecking wiring, earths, voltage ect....Holden still says to replace the whole wiring loom in the engine bay.."HELL NO"

[GTS308]

Ok put the new Memcal in and still code 49 shows up wich is Cam angle sensor intermittent, not Crank angle as I said in my other posts..So we pulled out the wiring loom through the hole in the firewall and opened up the little tape that was remaining holding the loom together reconected all the wires we bypassed earlier and sat the computer on the front of the car and tried again still code 49 shows up...Watching the Tech2 screen while the car is running it says the Cam sensor is present then not present flickering randomly..pulling and pushing every wire and plug makes no difference...So I rang around the wreckers for a 5ltr VT loom and they said good luck finding one that has not been molested in some way or another..Most of the engine looms are sold with the engines..As luck would have it Holden in Melbourne have 3 brand new ones still in stock (Dont ask about the price, Im getting a second mortgage on my house to get it)..It will be here Monday...

Now if this dont fix the problem Im going to asume the fetal position and bawl my eyes out...New Distributor, New Ignition module, new computer, new Memcal and now new Engine Wireing loom + labour = No christmas presents until 2045...Sigh!

One more thing was trying to find the 12v power supply to the A8, B8 terminals on the comp..Holdens wiring diagrams say Orange with a black stripe...There is no Orange wires in the engine loom at all...Turns out they are Purple..Good one Holden!

Cheers!

[50LTRv8]

Best of luck mate, All I can say is that you have far bit more patience than me, good luck

[seanpol]

was just wondering if you had resolved the issue with your vt as i have the same problem and mine has been put down to interference with the distributor rang the manufacturer RAE and they said this is a common problem with there vt distributors they sent me a modified one which has it running on all cylinders but still code 49 and rough idle

[mr j-man]

sounds like holden just raped the arse out of your wallet like they did with me when i had a similar problem

[seanpol]

went through 3 RAE brand distributors all had same problem my mechanic got me a second hand genuine bosch distributor and the car ran perfectly hope this helps anyone with similar problems with there vt 5lt

[GTS308]

No car is still in the shop...We have got it to run perfect until you drive it and hit a bump then it throws the code 49 again..Begining to think the problem may be in the wiring between the BCM and PCM thats the next step..

And no I have not been Arse raped..lol I have paid for parts but the guys are doing all the labour free because it has them stumped as well..

[ari666]

i dont suppose anyone has checked the cam shaft and timing chain? you do know that they can snap/chew out lobes/wear out gears etc

mechanics seem to forget there is a mechanical side to their job too. its not all about wires and computers.

[mr_d]

I have had a similar problem for over a year now, have replaced hall sensor,ignition modual,coil,leads,dissy cap and rotor.
Sometimes will start fine and run fine then other times will stop when driving then wont start and then sometimes will
start then stop. have tested continuity on all the wiring related to censor,modual and injection back to ecu.
Have had ignition and noid drop out at the same time and other times might be one or the other intermittently.
Have never had a problem like this with a car before and its busted my ass.

[Snake88]

hey, had any luck if not i suggest you check engine earth as i had very Simla problems with my v6 vt.

sorry if some one has mentioned this don't have time to read whole post atm

good luck hope you find the prob hate it when car plays up.

[jonboy]

crap!! my vtss has just done this after replacing cap/ rotor/ leads.
theres a new distributor on the way and as you cant buy genuine new any more its an aftermarket one.
im really hoping it fixes the problem 1st go and i dont have the same problem as the dude who started this thread :S

[vtv8excopcar]

hey just wondering if sum1 has the answer to this problem as my car is doing the same and can't find the problem

[Barter78]

Yep I'm in the same boat. Car runs fine cold then it warms up and dies. Mines on lpg as well so it's not fuel, does exactly the same thing on either lpg or fuel. I've replaced everything apart from the engine loom.

[Krisp]

just wondering if anyone has checked for vaccum leaks

[Barter78]

Mines a not vacum leak. Tacco does nuts just before it dies.