Manic_Mechanic
Turbocharged
Ok, finally got around to swapping injectors between the first and third throttle bodies. The problem stayed at the #3 position which lead me to believe that the problem is related to a sensor. Hooked up tuneECU and watched the diagnostics. I was trying to ballance the tb's but had no luck getting #3 close to one and two. I switched over to the middle tab in the program and monitored the injector pulse width. Here I found that one and two were close to 4.5 but three was staying at 3.5
This would explain why the engine runs so well at higher rpm's when the f/l switch kicks in and the metering is controlled by t.p.s and rpm and the m.a.p has no bearing on the mixture.
It appears that the e.c.u. controls each injector individually which I did not expect due to the fact that all three vacuum lines converge into one sensor. If I gradually pinched off the vacuum line from #3 TB I could see the pulse width ride up like cheap underwear and the idle smoothed out as well.
Now the only thing left is to pull the throttle body and check for a bad o-ring or some other seal. If this doesn't remedy the problem then I'm checking valve clearances.
Any input or comment is invited and welcomed.
This would explain why the engine runs so well at higher rpm's when the f/l switch kicks in and the metering is controlled by t.p.s and rpm and the m.a.p has no bearing on the mixture.
It appears that the e.c.u. controls each injector individually which I did not expect due to the fact that all three vacuum lines converge into one sensor. If I gradually pinched off the vacuum line from #3 TB I could see the pulse width ride up like cheap underwear and the idle smoothed out as well.
Now the only thing left is to pull the throttle body and check for a bad o-ring or some other seal. If this doesn't remedy the problem then I'm checking valve clearances.
Any input or comment is invited and welcomed.
