Huge post - Main problem is front four plugs are lean?
1- if you are having this issue you HAVE TO swap injectors from the front to the back. Move the lean ones to the other cylinders and the same with the rich ones.
2- If the problem follows the injectors, meaning now the lean cylinders are now the opposite, you have bad injectors.
The problem with noid lights are that they only determine if the computer is giving the injectors signal and they are also getting 12v. They do not determine if the injector is actually firing.
3- If the problem doesn't follow the injectors then you have a computer problem.
a- the computer isn't functioning properly
b- the computer isn't getting proper signals from other sensors.
c- the tune is f'd up!
1- if you are having this issue you HAVE TO swap injectors from the front to the back. Move the lean ones to the other cylinders and the same with the rich ones.
2- If the problem follows the injectors, meaning now the lean cylinders are now the opposite, you have bad injectors.
The problem with noid lights are that they only determine if the computer is giving the injectors signal and they are also getting 12v. They do not determine if the injector is actually firing.
3- If the problem doesn't follow the injectors then you have a computer problem.
a- the computer isn't functioning properly
b- the computer isn't getting proper signals from other sensors.
c- the tune is f'd up!
Installing a completely new set of injectors has been done. - No change
I have gotten mail order tunes from two separate reputable tuners and both had the same issues. Both have made adjustments from data logging......
I have installed an entirely new computer in the car.
It was left at a shop that fiddled with the tune for weeks and eventually gave it back to me without fixing it.....
I have a complete wiring harness sitting in my garage that I will eventually get the ambition up to swap. After that it's going to the crusher.
.......Later,
Brad
Here's some other ideas I can think of:
Remove your fuel rail crossover at the front make sure it isnt blocked by an o-ring or debris.
You could also remove the entire rail off the manifold and place little clear shot glasses (plastic ones) under each injector. Crank the motor a few times to see how much fuel fills each one. If the front ones are noticeably less at least you know its in your fuel system. I did that once to find a bad injector and it worked.
Are you sure the vaccum line on the regulator isnt too small or is collapsing?
I know it sounds redundant but what you are describing is what the guys with monoblades see unless they jump through hoops to put the IAC plenum back together.
If the IAC plenum is not used the front cylinders simple steal all the front fed air at low speeds.
Is the TB a cheap one where possibly the blades fit badly and are leaking a lot of idle air?


