99 VT Intermitant Starting problem.
99 VT 6cyl with random starting problem. Generally starts no problem in when cold, but have also had random start problem when cold or hot. Will turn over but will not start, then leave for an hour or two and will start no problem. Replaced fuel pump and fuel filter, filled up with last of clean fuel I had then drove to servo, filled up (premium) and then would not start!! (Motor was not even hot). This has happened at very random times, (even we have just hooked on the tow rope after 2 hours of stuffing around and then it starts!!) Hot or cold it doesn't seem to matter.
Replaced fuel pump, fuel and air filter, all relays and fuses, plugs, leads, and cleaned every terminal and wiring harness with contact cleaner and dielectric grease.
I've tried the cold water (and beer) on crank angle sensor (does not conk out or stall once hot).
When it does have the start problem, the fuel pump does run, but does not sound like it pumps up with enough pressure (even though I just replaced it). Not sure if I missed something. All connections looked ok in the tank and wiring. I had been advised it may be a fault in computer (but no errors at present) or something about a "ghost key" (ignition barrel was replaced not long after buying the car).
Also the vehicle only has 74,000km's, I bought it at 48,000 about 4 years ago. Hasn't skipped a beat until now. It even sat at the mechanics for a week, but low and behold it started no problem for them every time!!
Please any advise would be much appreciated.
Donating Member
It won't turn over at all in that case.Originally Posted by Shen Long
Perhaps an immobiliser problem, check the security light is not flashing when the problem occurs.
MY RIDE
I thought I was wrong once but I was mistaken.
No security light flashing.
I'll get the immobilizer checked and the key reader (seen on another post).
Key is ok, remote unlocks and locks , but the spare key is dead flat but will start the car ok (when it starts). I have read that you may as well through the key away once flat.... how come the spare still works???
How do you know it does not pump enough pressure? You need to put a pressure gauge on to it mate.
Also when she is playing up check for spark.
when it's starting fine heat the crank sensor with heat gun or hairdryer until hot then try again.
if it won't start then try lots of cold water and try again
if it still starts when hot it's probably not crank sensor
and like pravx 11 s said when it wont start see if you have spark and fuel pressure
Could it be your coil pack? Mine was doing this and Id just replaced my fuel pump and thought it had gone again. RACV came out and said Crank angle sensor. Then I remembered back to an aunty who had a coil problem in her car decades before. I went and swapped the coil pack over and it started no problems. Turned out I had a rusty pin on one of my coils. Some steels wool and a good clean up and I put the old coil back in the spare car and it worked fine too.
Try a new battery. You have had the car longer than batteries last these days. Mine dies every 3 years. Doesn't matter what brand.
I think that you're getting all the correct advice.Sounds like a crank angle sensor cos you seem to be more likely to have a problem when it's hot but there's a slim chance that it could be your coils &/or the DFI ( coil pack includes all 3 coils + the DFI module ) Just be aware that if your crank angle sensor does totally pack up you will need a tow truck cos it's not a job that is easily done at the roadside.
Thanks for the replies... still having start problems.
Changed coil packs - no spark when having problem.
Key reader seems ok.
Tried plenty of water on CAS.
Replaced battery not even 12 months ago.
Fuel pump "sounds like" it does not pump up enough pressure. I said this because as soon as I turn the igninition on, I can tell whether it will start or not from the sound of the pump. Although I have not had a pressure gauge on it.
It does not seem to be a heat problem as it's never stalled or run rough once hot (which I was not suspect on the coil packs or CAS). I'm yet to get the immobilizer checked out, but not having any security lights or error codes to say that's the problem.
"Started the car last week end, drove around no problems. Tried it couple more times through the week, would not start. Tried again yesterday, would not start, tried again this morning, starts first go!! Turned it off, tried again (straight away), wouldn't start."
Does it seem as though the immobilizer could be the issue?? or anything.
Sounds like you key head is going flat. U could be wrong. When it does it take the key back out of the ignition. Lock your doors then open them again try start the car. Worth a try worked for me until the battery went dead and could only start it every now and then. Would either start and stall or only try to crank. New head and working fine.
crank angle sensor will do these type of things. 'pouring' water around the sensor wont diagnose it correctly but it may get u you of trouble. to change the sensor u have to pull off the harmonic balancer and its a bit of a pain to do so its not a simple 2 minute job.
Hey mate I'm having the EXACT same problem at the moment, sometimes will start fine for a few weeks then out of no where will decide not to start (usually when I'm on my way somewhere important) and always starts for my mechanic so he can't diagnose it.
Got the usual responses from the mechanic could be CAS, Coil pack or fuel pump
Most times I hear the fuel pump prime when I turn the ignition on but when it doesnt start no noise from fuel pump? replaced fuel pump, the relay's and fuses as well but still not fixed.
If you find out what it is let us know and if i find out any more info i'll post it up here!
Pouring cold water over the CAS will only work in cases where the fault is being caused by heat. These CAS's can also stuff up from other problems not related to heat, so the cold water wont help in a lot of cases. The only way to be sure about the sensor is to take into account the km the car has done, the last time the CAS was renewed etc, and go from there. If the engine has done over 100,000 km, then its worth replacing the CAS as a precautionary measure, its the same with most other engine sensors like the oxygen sensors etc too. Also Ive seen some cheaper aftermarket parts fail fairly early on in their life, so its best if you can, to stick with genuine holden parts when it comes to engine sensors or ignition coils etc, even though they cost more, they will in most cases last a lot longer than the cheaper parts, so they can actually work out to be cheaper in the long run.
The best way would be to test the CAS sensor on a oscilloscope. See what pattern its giving out. only then you will know what the CAS is dong.
Also you said your not getting spark when the problem is happening.
you will have to check the IGN side of the system.
Cas,DFI Module,EFI relay,
Fixed!!! Had the CAS and the piece the coil packs sit on (can't remember the name) but it's up and running.
Should have got them done in the first place, but I was happy to replace everthing as all originall.
Thanks for the replys.
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