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Gary
Gary, Buick Technician
Category: Buick
Satisfied Customers: 16393
Experience:  15 years master GM tech and mater ASE tech
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I have a 2000 Buick Lesabre with a misfire. The code has

Customer Question

Hi, I have a 2000 Buick Lesabre with a misfire. The code has been checked twice, showing each time cylinder no. 6 misfire. What is strange is that the misfire only really happens on cold start up, for 10-15 seconds, then smooths out. Occasionally on a longer trip (more than 20 or 30 minutes) I will feel it misfire again, but very briefly, and then it is fine. I have changed the plug, run another coil, and swapped the upper and lower intake manifold gaskets (which needed to be done anyway, as it had a coolant leak into the engine. I thought this was the source of my misfire problem, but apparently not.) You mentioned in a previous reply to someone with similar issue that it could be a lean injector, fixing the problem upon going into closed loop. I didn't think that engines went into closed loop within 10-15 seconds, however. What is causing no. 6 cylinder to misfire when cold? Thanks for any help you can offer!
JA: How old are the hoses? And have you tested the actual mix of your coolant?
Customer: I'm not sure what you mean.
JA: Are you fixing your LeSabre yourself? What have you tried so far?
Customer: Yes. Read post above.
JA: Anything else you want the mechanic to know before I connect you?
Customer: no
Submitted: 6 months ago.
Category: Buick
Expert:  Gary replied 6 months ago.

Welcome! My name is ***** ***** I will do my best to assist you with this problem.

Expert:  Gary replied 6 months ago.

the best way to rule out a fuel injector is swap # 6 to # 4 injector will the misfire move to cylinder # 4 ?

if it does the injector is bad

it sounds like you ruled out everything else just be sure the compression matches the other cylinders but the odds are it is just the injector

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Customer: replied 6 months ago.
Thank you! That occurred to me but I thought I'd ask an expert in case I were missing something obvious.
Expert:  Gary replied 6 months ago.

anytime

dont forget to rate us here

you can always get me back for FREE for any follow up any time with this question even after you rate me here at Justanswer

if you have any questions please ask as i do not get credit for my work until you rate me here at Justanswer

Expert:  Gary replied 6 months ago.

how are you making out ?

dont forget to rate us here

you can always get me back for FREE for any follow up any time with this question even after you rate me here at Justanswer

if you have any questions please ask as i do not get credit for my work until you rate me here at Justanswer