#1
21st April 2010 - 08:56 PM
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I have a 3.8L buick motor in my VR that I bought for my brother and as of late it is running rough as guts. It has been sitting for a while but I have been turning it over fortnightly. The motor starts fine but sits there hunting and trying to find an idle and eventually dies. The exhaust seems to smell very much like unburned fuel and it has backfired (possibly running very rich) The tank is clean and the fuel pump is giving good pressure, the coils are all throwing a decent spark. My brother wants to drive his car but it is undrivable at the moment, please help. -------------------- Too many past rides and not enough current ones.
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iamhappy46
Post #8
I would hazard a guess that one of the injectors is damaged and flowing excess fuel into the engine on one cylinder. I would also strongly suggest replacing the exhaust O2 sensor as well |
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eurekamad94
Post #9
try doing a self diagnosis on your car, here's a guide with all the codes |
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iamhappy46
Post #14
if u increas the gap of ur spark plug it will help with how rich u run just dont go over bored 1 or 2 degress larger and it will help heps LOL. Please dont take this advice. Opening the spark gap on an engine that is running rich cause misfires = no spark at all = MORE unburnt fuel in the exhaust. They also measure it millimetres not degrees of gap |
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iamhappy46
Post #16
if u increas it buy 1 mm it will fix the problem ask a mechanic oh hang on how bout u ask me im a fuking mechanic FUCK... GOD HELP US. How many years more experience do you have over me? Based on your past threads, I would say negative 15 years. Increasing spark plug gap(not degrees) requires the spark plug to increase its time in the capacitive phase(building up charge before it can arc over the gap) which means that there is MORE compression occuring in the cylinder and is more likely to miss. Actually, if an engine is running rich and the engine is not missing then there is excess fuel in the combustion chamber which 'cools' the mixture further so widening the gap actually makes it less likely to fire. REDUCING the spark plug gap makes it easier to arc over in the capacitive phase(resulting in a longer inductive phase) which is more likely to burn all fuel. However, since a qualified mechanic would look at the problem and DIAGNOSE that either the O2 sensor is out of range or a fuel injector is supplying excess fuel(possibly MAP sensor but unlikely as Closed loop would bring the mixture back within stoich mixtures) is the likely culprit, then you fix the problem and not apply a bandaid solution of playing with spark plug gaps. If this is based off your expreience from your 175Kw Commodore... maybe you should look at my 481rwKw VY SS ute I built and see where a real commodore makes power Please improve your diagnostics skills before you attempt becoming a member of the Technical Members group |
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TwinCam16
Post #17
if u increas it buy 1 mm it will fix the problem ask a mechanic oh hang on how bout u ask me im a fuking mechanic At the risk of backing up iamhappyrootingsheep46, he is right. I mean, how can you claim to know your shit when you post This... https://www.boostcruising.com/forums/index....;pid=1285710860 ... this.... https://www.boostcruising.com/forums/index....;pid=1285710730 ... and THIS?! https://www.boostcruising.com/forums/index....;pid=1285710479 |
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iamhappy46
Post #18
But wouldnt that be less seeing as thou the car is powering 2 wheels instead of 1???? ^^ My personal favourite |
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TwinCam16
Post #21
On topic - there is a few things you need to check. |
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TwinCam16
Post #23
The more i read it the more it sounds strange. |
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iamhappy46
Post #24
Remove spark plugs |
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MaccaColt
Post #29
We had a VS commodore once |
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