Engine running on 2 cylinders - partially solved, 2001 172

[matt hromadka]

Hi everyone,

I had a problem with the engine running first on three cylinders and shortly after that on just 2 cylinders on my 2001 172. I was really scared that it was a mechanical problem since it was running on just 2 cylinders, but fortunately it was a combination of one bad spark plug and a bad injector. Thus I changed all of the injectors and the spark plug and the car now (mostly) runs on all 4 cylinders.

However when I stand on the throttle the car seems to run on just 3 cylinders and when I push the throttle almost all the way down there is a sort of lag before the revs start to go up (really simillar to an old turbo engine with plenty of lag). But when it starts going it's going great, much better than anytime since I bought the car.

I am still going to replace the lambda sensor since I know that the precat one is faulty and I am waiting for an NGK plug since they only had a different brand here where I live. Can the problem be due to any of these or should I expect it to be a bigger problem?

Txs for any tips!

 

[GrahamS]

Watch me!!! You night still have an injector issue. Are you leads on correctly, sounds obvious but it's an easy mistake to make.

 

[Canary172]

It's best practice to replace all 4 spark plugs at the same time - I don't know why you would only replace one.

Misfiring could also be dodgy ignition leads. Check condition and resistance over the existing ones, and replace with OEM Renault if necessary.

 

[Vaughan]

Make friends with somebody with a well-running 172. Swap over the coil pack and plug leads and see if there is any difference. Saves buying unnecessary parts.

Assuming that you've already got the basics sorted like fuel filter, battery, earth points, crank sensor, injectors, injectors, injectors. Could also be belt timing slightly out too.