Running rough (cold)

[Patch234]

So, after a great drive yesterday, and parking her in the garage, smooth and no problems later last night; upon starting the car this morning .... running rough as a dog. Sounds like it is running on 3 cylinders and it's smokey!! Any advice chaps?

Thanks

 

[Patch234]

As an update ....... 10 minutes later ......... went out, started her again, and no problem?? Thoughts on that?? HMmmmmmm

 

[Hallsy]

Leaky injector maybe causing over rich running on initial startup?

A fuel pressure leakdown test might shed some light.

Failing that, check condition of dizzy/rotor/plugs.

Failing DME temp sensor can also cause rich running, easy enough to test, or cheap enough to replace if suspect.

 

[Patch234]

Thanks Hallsy. The strangeness continues - would not start last night, this morning it did, running rough again?!? God, CARS!!

 

[Hallsy]

When it does start, presumably it is misfiring and smoking?

Does this clear soon after or once revved?

A visual check in the dizzy cap, rotor and plugs will be easy enough - contact points on cap & rotor should be clean, without excessive pitting/wear. The plugs should be tapped correctly, and a mid brown colour.

To test the fuel system you will need a fuel pressure gauge - there is a write up on Clarks garage website to check fpr and also a leak down test.

The DME temp sensor can be checked in hot/cold water by testing resistance at different temperature, there is a chart online for the sensor - I have it somewhere. They are fairly cheap though, so if no record of it being replaced it wouldn't hurt to change it anyway.

 

[Patch234]

Yes, it clears once reved up after a while, or when taken for a very quick once around the block. The plugs are new, I changed the DME (got one here) and nothing changed last night; it still would not start. This morning started, very rough, ran it around the block, two mins, and all fine!! I will look into the dizzy cap Thanks.

 

[edh]

I'd have a look at Clarks garage website - there are some great troubleshooting guides on there

http://www.clarks-garage.com/

 

[Eldavo]

It's because you cleaned it - it's throwing a huff.

A mate bought a Rover Metro and drove it from Cowley to Casablanca with nothing more than a cursory check over. He said that once you touch the first rusty screw then who knows what else needs doing []