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bdw18_123 · 09-30-2011

Ok, just got back from a little drive. I cleared the codes first (was the same 44 & 55) and I kept the power key off the whole time. For awhile, the check engine light wasn't coming on just cruising at normal rpms, so I figured maybe get the revs up and see what happens.

So kept it in 4th and got the engine to just about 5K and then shortly after the light came on. So this isn't just a problem with the secondaries, it affects the primaries too. Got home and pulled the codes and yup, the same 44 & 55. Always the same, only the left side. The right side never throws any codes. However, from reading what the manual says on code 55, this code seems to be only for when the secondaries are enabled. How could I get this code with the power key off? Another mystery to unravel...

Several of you have suggested checking the fuel pumps, but as I have stated they are both brand new. Now I know brand new things can be bad, but like I have already asked, how can a bad fuel pump only affect the left side so consistently? That just doesn't make any sense at all.

a1991zr1 - If the injectors on the left side were leaking down, I would think I'd be getting codes indicating a too-rich condition, not a too-lean condition. I think the problem may in the injectors, but I think maybe they are not flowing enough at the higher rpms.

I haven't pulled the plugs yet, so I think tomorrow I will pull the right side and left side plugs and compare them and see how they look.

09-30-2011	#12
bdw18_123 Join Date: Apr 2009 Location: Prather, CA Posts: 804	Re: 1990 exhaust manifold issue... Ok, just got back from a little drive. I cleared the codes first (was the same 44 & 55) and I kept the power key off the whole time. For awhile, the check engine light wasn't coming on just cruising at normal rpms, so I figured maybe get the revs up and see what happens. So kept it in 4th and got the engine to just about 5K and then shortly after the light came on. So this isn't just a problem with the secondaries, it affects the primaries too. Got home and pulled the codes and yup, the same 44 & 55. Always the same, only the left side. The right side never throws any codes. However, from reading what the manual says on code 55, this code seems to be only for when the secondaries are enabled. How could I get this code with the power key off? Another mystery to unravel... Several of you have suggested checking the fuel pumps, but as I have stated they are both brand new. Now I know brand new things can be bad, but like I have already asked, how can a bad fuel pump only affect the left side so consistently? That just doesn't make any sense at all. a1991zr1 - If the injectors on the left side were leaking down, I would think I'd be getting codes indicating a too-rich condition, not a too-lean condition. I think the problem may in the injectors, but I think maybe they are not flowing enough at the higher rpms. I haven't pulled the plugs yet, so I think tomorrow I will pull the right side and left side plugs and compare them and see how they look.