Half of motor running lean....

[88hatchblack]

I just got the insurance on my car and took it for a drive. Everything went OK; and as it's a new motor I took it fairly easy. after about 45min I came back home to pull some plugs. turns out plugs in cylinders 1-4 are good; nice color, little brown on the ceramic. but cylinders 5-8 are lean. there is bright whitish gray on the plug, and no brown on the ceramic. What Gives? I'm going to the strip Friday. FP is at 38PSI with 24# injectors. Timing at 14*

 

[88hatchblack]

....anyone?

 

[Nutzy19]

o2 sensor .... just did mine cause of same problem....

 

[88hatchblack]

I forgot to mention I bought two new Borg Warner O2's

 

[Pops Fun]

Check and make sure the O2 sensors are wired to the correct bank..... Since you changed them they could be mixed up????

Steve

 

[dstanggt50]

I think that #6 and 7 generally run leaner than other's, you could always do the koer test that turns off the injector for each test and see if you get any codes back from it. Also maybe turn up the fuel pressure just to see how it affects the plugs?

 

[88hatchblack]

i'll check the wiring and grounds, then pull the codes. When I turn up the FP, cylinders 1-4 get super rich, while cylinders 5-8 look good I'll just have double check everything i guess
thanks for your help!

 

[Insane3D]

How about the injectors on that side? Are either of the two rubber lines connecting the left and right fuel rails kinked at all?

Just an idea...

 

[88hatchblack]

pulled the codes and the only abnormal code I got was for the ACT sensor, so I bought a new one. Didn't Make a difference

 

[TT91]

How about switching injectors from pass side to drivers side to see if they are causing the prob.

 

[88hatchblack]

How about switching injectors from pass side to drivers side to see if they are causing the prob.

I fixed the rich/lean problem by messing with the fuel pressure and sanding the O2 grounds. I guess there was probably a bad ground to the O2's...

 

[88hatchblack]

It still hesitates when you tap the gas though; and the idle wanders and likes to surge and stall when stopping after pushing in the clutch. I pulled the codes and got these: Running: 33, 44. Key On Engine Off: 67, 82, 81, 85, 84, 93, 32. Could any of these be the problem? thanks in advance! one more thing- Fp is 42PSI VAC off, and timing is advanced to 14*.

 

[88hatchblack]

could it be the mass air sensor even though there isn't a code? because throttle response is better with it unplgged but idle is crap.....I'm really confused

 

[Pops Fun]

It took mine a few days driving to settle down and it took 3 weeks or so for all the problems to go away.

Drive it...