2000 Daewoo Lanos Random/Multiple Cylinder Mis-fire Code Tr

LANT

MEMBER
2000 DAEWOO LANOS
4 CYL
FWD
MANUAL
172,000 MILES

I am trying to solve a check engine code that indicates a random/multiple cylinder mis-fire. I have replaced the plugs, plug wires and coil. I paid my mechanic to replace the crankshaft sensor, because he said he thought that might be the problem. The car does not have a perceptible mis-fire, accelerates well, and general drives fine. Sadly, I can't pass the annual inspection without getting this problem solved. My mechanic is out of suggestions, so I am hoping you can help. Thanks in advance for any suggestions you can provide.

Sunday, February 7th, 2010 AT 6:09 PM

3 Replies

SERVICE WRITER

MECHANIC
9,123 POSTS

When the misfires occured, were they linked to particular cylinders?
IE
po301 is cyl #1
Po304 is cyl#4

What codes do you have?
This is important.

IS the fuel pressure in spec?

Was the engine compression tested?
Was a leak down test with the valves closed performed?

These engines has some troubles with fuel injectors, but I want the codes first.

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Monday, February 8th, 2010 AT 5:07 AM

LANT

MEMBER
2 POSTS

Thanks for your reply. The only code I receive is P0300, with no reference to a specific cylinder reference. The fuel pump was replaced within the last year, but I don't think that the fuel pressure, compression, or valve leak was tested.

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Monday, February 8th, 2010 AT 7:08 AM

SERVICE WRITER

MECHANIC
9,123 POSTS

Well you need to find out what is missing. Compression, fuel or spark.

Did the shop test at all? Why did they go with the crank sensor?

Since all of the cylinders are missing we need to go after what will include all of them. The above tests may lead to the solution. Jumped time is one thing that needs to be checked. When was the last time a timing belt was put on her?

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Monday, February 8th, 2010 AT 5:42 PM