Leaking/Stuck Injectors...Does This Sound Right?

[brn agn]

I have about 58,000 miles on my TTA. As far as I know, it has the stock injectors. The car has always ran rich at WOT (high 800's-mid 900 mv). Keep in mind I am using Diacom as a scan tool, so the O2 Voltage is shifted about 50 mV higher than the other scan tools. Anyway, I was playing around with it this weekend, trying to do a little tuning. When I got home, I pulled the spark plugs and the #6 plug was black with a lot of raw gas on it. The other plugs looked white...as if the engine was running lean. Because of the one rich cylinder, I had suspected that the fuel injector may be bad. Plus, I have had problems with fuel pressure dropping to zero within an hour after the engine was shut off, and I have also had a hard start issue for awhile.

So, I pulled the injectors out of the intake manifold and cycled the key on to prime the fuel system. I then watched the fuel injectors. 2 of them started to drip ever so slowly...while the injector on the #6 cylinder showed no signs of leaking. Visually, they all have some varnish and buildup on them. I am planning on sending them off to be cleaned and flow matched. But before I do, I wanted to see if anyone has had similar problems (one cylinder running really rich)? I had this same problem on my old 87 IROC-Z and it turned out to be a bad MAF. Don't ask me why...but it caused the #8 cylinder to run rich...of course this was a batch fire system also...so the inefficient air metering may have been affecting the fuel distribution? Any advice or insight is appreciated...thanks!

 

[Black Car]

You could swap the #6 injector into one of the other position and see if that cylinder ran rich.
The better choice is to have them check/cleaned or replaced with bigger ones.
Here is a good place that does injectors.
http://www.cruzinperformance.com/fuelinj.html


Gary

 

[brn agn]

Gary, as far as swapping injectors, I was thinking the same thing...

However, I know they have some miles on them, so I think I will send them off to be cleaned regardless.

Thanks for Rich's website. I sent some injectors to him several years ago and was very pleased. I had forgot what the name of his company was until you posted the website though.

Another possibility I thought of last night is if my injector harness is shorting somewhere...I don't know if this could case the #6 injector to pulse more than it should? I will be sending the injectors off for cleaning as soon as possible. I will post back here with the results. Thanks again.

 

[Black Car]

If your injector harness was shorting out on an injector then it wouldn't be pulsed at all whiled shorted out.

Getting them cleaned & flowed will elminate concerns about the injectors. If the harness is shorting out will be another problem, while the injectors are out you could check (ohm out) the harness for breaks in the wires.

Gary