Hi guys!
I will start by saying im new to this fourm and I was impressed by the knowlage of its members.
I own an NF V8 Fairlane with 450,000k's on the clock that i got of my dad and have been diving for the last few years.
I only got it put in my name a month or so ago and i am having issues with the gas.
A bit of background info first would help. I have just spent around $3,500 getting the car up to scratch for RWC. On the gas system side of things i took the car to a gas place around the corner from me cos the gas wasnt running. They charged me $900 to change over the gas converter, changed plugs(they wer 2 months old and corect) and a tune. The tank needed to be re stamped so i took it out and had it done.
Lately the car has been having trouble when I turn the wheel or slightly touch the throttle. I was told by the mechanic that did my road worthy that it was most likely the stepper motor. Over the last few days this week I have compleatly pulled the throttle body down and gave it a good going over. Last night when I started it and took it for a test drive it was still having the same issue but the performance/smoothness was heaps better.
There is an exhaust leak in the left hand bank and the intake mani gasket is leaking.
I did give the car a quick tune by using the fourm guide and its idleing better. If I pick the rev's up and relese wether its hot or cold it will stop and hold at 1200 rpm before droping to 800rpm. I also disconected the stepper motor and started the car and it seemed to run fine if not better without it?
Im getting sick of working on the gas and i need to fix it before i go freakin mad!
Any help would be appriceated and i thank you for taking the time to check out the post. Pete AKA JAPCRP
Will post some pics of the gas system when i work out why it wont let me

Both these will cause the car to run s**t.

depending on how big the leak is in the intake manifold - just to test if it make any difference seal it up with some silicone or gasket goo if possiable, but only if it is a small leak.

worked it out..... files were way to big, opps

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Yea i tride that and it didnt work to well. its not leaking badly but bad enuff.
Just took the car for a test run and noticed there seems to be a heap of liquid coming out of the exhaust even though the motors been running for ages? when i took off after having the car run for 5 min there was a trail behind me? hmmmm im just sick of having to work/fix things on this money pit!

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Are you sure that is not coolant leaking there ?
have you done a compression test ?

yea it is and the next thing i need to get done. im going to fix the gaskets on the intake and i bought a set of paceys so i will fix the exhaust leak as well. hopefully fixing these things will help?

They would be the next things i would fix based on what you have said.

Good luck with it.

The ecu controls the idle speed drop (from higher revs, like a blip on the throttle) using the ISC, and the pause at 1200rpm is completely normal. Disconnecting the ISC takes this control away from the ecu until it learns it's way around this by using timing instead.

Hi mate
Vacuum leak will definitely not help situation. But I had exactly same problem though mine is a six. On top of ther convertor there is a switch with a wire two wires on it check the condition of these wires and make sure everything is tight.

Good luck

Steve

be careful when removing the intake manifold bolts, they will most likely be corroded and will break easily, good luck

turns out my intake mani had gone porus.
car is in at my mech to clean up the motor...
change intake mani, new water pump, new starter, new street strip cam's, new lifters, new welsh plugs, change hoses, pacemaker extractors put in, rear exhaust section repalced without rear muffler, king lows all around with munroe gt lowered springs in the rear and a heap of other stuff i cant remember.
he said the motor still has a 100psi comp on all cylinders witch is suprising due to the amount of k's. looking forward to a better running v8 fairlane.
still not sure what to do about the gas system though. i believe injection systems are the way to go? has anyone had it done to an f-l series 5ltr if so how much did it cost ya?