Refreshing an M20

[ADlBOO]

I'm looking to spend a couple hundred dollars to refresh my engine and make it run better and more reliable. I did a full tune-up in February of this year minus wires which I'll prolly get this time. I'm thinking along the lines of all new vacuum lines, sensors, fuel pump. Looking for ideas of anything I might be overlooking. Thanks!

[Cabriolet]

changing the lines is good. but if the sensors aren't bad don't waste the money. a full engine refresh it money well spent. (rings, bearings, seals, arp studs, OE head gasket, etc)

[ADlBOO]

Eventually I'd love to get in and rebuild the engine. As far as sensors go I'm gonna replace the exhaust 02 cuz I think it's shot. I was wondering if there's any sensors that can cause the car to run not ideally and not throw a code that might be worth changing.

[Bearmw]

Rather than just randomly changing sensors and so on I suggest doing a bit of research (Bentley manual, etc.) and test what you have. You will learn how the car operates and probably save some dough. It's likely that some parts are marginal but test to be sure. I would closely inspect the plugs and 02 sensor (the NGK website has some good info on reading plugs, etc.) and also carefully test for intake leaks for starters.

Good luck

[ADlBOO]

I have the Bentley and went thru and tested my 02 sensor. But my car is throwing the cel for a bad 02 sensor even though it tested good.

[jlevie]

The O2 sensor is a scheduled maintenance item with a replacement interval of 100k, so it makes sense to replace it. The other sensors are pretty much a go-no proposition and if one of them is bad there will be obvious symptoms.

An O2 sensor fault can result from a bad sensor, or an upset in the A/F ratio. The most common cause of the latter are intake leaks, which a smoke test will find.