Hey peoples,

Earlier this week I changed my TE's injectors with Aznew cleaned ones & new filters. Have done 200km since the swap & has been running perfectly.. Until this morning...
When I jumped in to go get some macca's for brekky the old girl just cranked over without starting up. I put my foot on the throttle a little & tried again. It took a few cranks but it fired up, ran a bit rough for a few seconds and was then fine.
It has done the same thing each time I've tried to start it today.. seems to start OK when warm, not straight away like normal, but don't have to crack the throttle like when it's cold..

Anybody got any similar experiences or even better, any solutions?

I've disconnected the battery & am gonna reset the ECU & see if this helps..

Any help appreciated!

Sounds like either your MAF or Idle Control Motor. Does it stall if you let off the throttle?

I remember a similar thing happening to my son's Commodore - injectors were leaking/dribbling causing an over-rich mixture which would not fire till throttle was opened to dump excess fuel. When warm hot no problems as only happens after a few hours when injectors had dribbled enough.

Doesn't stall once it runs, only reluctant to start when cold.. Starts when hot but not as I feel it should, as in it cranks a bit more than normal but fires up ok.. Doesn't have the usual start spike & slightly high idle for a second..

You can check if it is leaky injectors by observing the exhaust when you start - if it blows out black smoke it indicates a rich mixture......but if no smoke then maybe it's running too lean which could be caused by (among other things) a faulty coolant temp sensor telling the ECU the engine is hot when it really is cold and needs a richer mixture. Have you checked all vacuum hoses are still in place especially around throttle body and the connector hasn't been knocked off the CTS.
Just out of interest, Magna injectors were a popular mod for VN Commodores as they flowed better due to 3 holes versus 2 on Commodores and Falcons.

Well, after resetting the ECU all seems to have returned to normal..
Thanks for the info Hako! Both sets of injectors (old ones & replacements) all have 4 holes in each. Could be a better upgrade again?

Thanks guys

I think the Magna injectors were from the 2.6 motor plus that was back in the early 90's so I guess there have been a few changes. Great news that an ECU reset fixed the problem.

It seems the ECU reset actually didn't fix the problem :mad:
Same issues are still present but after taking it for a reasonable drive to give the ECU a chance to regather itself the idle is really low, like around 4-500rpm when pulling up at lights etc and it also drops right under 1000rpm when I take my foot off the throttle..
Without having a close look it seems like the idle control motor might be causing the problem? Would a faulty ICM cause problems with startup?

Thanks for your responses so far!

A few things you could try:
- Check and see if the injectors are seated properly, with the insulators in place
- Make sure all connectors are plugged in properly, and give each on a bit of a wiggle - try starting. If it starts, could be a faulty plug with a broken connection
- Make sure the throttle body and plenum gaskets are in place and sealing correctly. Unmetered air and loss of vacuum is a bad thing!
- Make sure all the vacuum hoses are connected properly and have no cracks. Perished or non-connected vacuum hoses can cause all sorts of problems
- Check the PCV valve and hose. A bad hose can cause the engine not to run, or even a bad seal on the PCV valve. Shake the PCV value and make sure there's a nice rattle in it (not a dull one). Also clean it up and blow in to it (make sure its clean so you don't get oil on your lips, its not good for you! The flow should be only one way, that is blowing through one way it should be easy, blow from the other end and there should be no flow. If there is, purchase a new one or use some throttle body cleaner through it. Even a clean one make sure you run throttle body cleaner through it at least once a year (as well as checking it).
- Clean the MAF sensor with MAF sensor spray cleaner. You may have contaminants on the sensors
- Your ISC could be contaminated, I'm not sure the best thing to clean it with but throttle body cleaner may be ok?... (its the little holes on the inside of the throttle body where contaminants could have got in). Realistically, I'd presume if the ISC is not working, it should be possible to compensate with a bit of throttle. Its not a fix though in the sense of adjusting the cable position as the throttle body needs to completely close when you turn the engine off.
- Your fuel system could be blocked. Bit late now but Nulon Total Fuel System Cleaner is a good thing to use on your next refill, even if its caused by another issue. I assume you replace the fuel filter already, in the process of replacing it or the fuel injectors you may have released some gunk into the system

I'm sure there's other simple or not so simple things that could be the cause, but if it is the ISC its one of those 'just happened to occur at the same time' issues that though plausible seems a little too coincidental.

OK, so the first thing I've noticed is the PCV valve is full of crap & definitely not working as it should.. cleaned it out and still flows both ways. What are the problems this can cause?
So now I'm off to supercrap to get a new PCV valve & some TB cleaner!

Have now cleaned all intake components, car is running very smoothly & has a nice crisp throttle response, ECU has sorted it's shit out and all seems good.. Only problem is that it still doesn't like starting without some throttle after it's been sitting for more than a few minutes :angry:

I had a weird thought whilst driving home tonight & would appreciate peoples advice as to whether I'm leading myself up the garden path or not!!
With EFI fuel delivery systems the fuel lines must be at a certain pressure for the injectors to operate properly..
When the car is switched off I have read reports & experienced first hand that a substantial amount of line pressure is retained after the engine has shut down.

My question is :- What prevents the fuel line pressure from bleeding back past the fuel pump after it has been shut off??
I assume the fuel pump is not a positive displacement pump as they need to have a priming source, whether that be submersion or a "lift pump" arrangement..
So is there a check valve in the fuel filter or similar? As I replaced the fuel filter at the same time as I replaced the injectors etc..

Any help greatly appreciated!!

I think i've got somewhat the same problem with my 96 TE. Sometimes has trouble starting and i have to give it abit of gas and it starts. Then there is abit of smoke from the exhaust when it starts, it revs in idol lower than 1000 and shudders more than it should. In addition to this my engine warning light comes one when i get going. Found any fixs? I tried looking at the maunal to check the engine warning light but seemed beyond my mechanical skill level and dont want to risk damaging my cars electronics.

Problem turned out to be one or more injectors seeping when the car was shut down. Swapped the injectors with a second hand set and problem instantly rectified! Injectors now being sent back for testing / fixing!
Stingl - Does your exhaust smell like unburnt petrol for a few seconds after it fires up? If so, then you might have the same thing happening.. Not sure about the engine light coming on though? Good Luck!

good news Alan 4 . i had the same once before on another car. paid a guy to reco all 4 injectors and they were leaking after id put them in. took me a while to find the problem as i didnt know too much about EFI at the time.