[Engine] Poor starting

[Bryan-G-]

Hello, I recently had my timing belt go, teeth went, I had a new belt pump and pulleys replaced but it turned out also needed new cam. It is now back an running perfect but the problem is starting, it always starts but it turns over for 2 or 3 seconds where it used to be instant. The local garage can’t find the problem so any ideas greatly appreciated.

[Zion]

Which engine, 1.6 HDi?

If it is, there may be latent bleeding down of the rail pressure over night, does it start instantly after running and being switched off for a minute or two and then starting again? If it bursts into life and a touch of the key when it has been runnign very recently but not if left overnight, I'd get them to check the fuel system, leakback pipes, filter casing etc.

There could also be a small air leak into the fuel system after being disturbed.

[Bryan-G-]

It’s the same cold or warm

[Zion]

Ok then look for air pockets in the fuel system, it can take ages to get rid of.

[Bryan-G-]

Had it back for a week It’s 17 plate hdi, I’m afraid my mechanical skills only stench to changing brakes and the like.

[Zion]

I guess it's back to the garage then. If it is air and there isn't a persistent air leak (ingress) somewhere then it will eventually sort itself out. Especially if you can do a sustained motorway drive where fuel demand is higher and the chance to self bleed will be better.

Quick starting in diesels is down to 3 things. Good fuel pressure, fast cranking speed (good battery and starter motor) and finally good compression to aid the rapid heating of the air in the cylinders.

If it cranks quickly and easily but takes a good few spins to fire, I'd be looking at the fuel system first. Especially if it runs sweetly once started and doesn't smoke or have high pressure at the oil filler / breather then compression is likely good too.

Just take it back to the garage and explain its not starting like it used to.