What I can't understand is why she will start easily a couple of hours after refusing to start. Furthermore, once she gets going, for the rest of the day she will start up without any problem.
I note that when the engine is repeatedly cranked the first time in the morning and she refuses to start, there is no smell of fuel, which does suggest a fuel pump problem.
I have got a new fuel pump from Walloth & Nesch. It arrived here in Malaysia a week after I ordered it, which was simply amazing.
Will changing the fuel pump resolve this problem? Is there any other possible cause for this problem?
Once my 315 just quit while driving and would not start. But after some minutes waiting, it would start. But it would die again. The longer the wait, the longer the engine would run. It ended up being a dented fuel tank. The sending unit got way to less petrol, but over time, it would fill up again and the pump would empty just the sending unit.
Testing such problems is really about excluding things. 'Does not start' can mean a lot of things, so you have to exclude stuff. Pull out the injector and try to start, verify whether you have a spark. Remove the hose from the fuel distributor and look for petrol spraying out. Such things will narrow it down.
But after some troubleshooting by my uncle (who used to fix anything from Land Rovers to tanks in the Malaysian Army), he said he thought it was the fuel pump. Hence, when we first gave the fuel pump a knock, the old girl came to life immediately. Now knocking the fuel pump does not really help. We have to wait a couple of hours after trying to start her before she immediately fires up. Then she is fine for the rest of the day.
The fuel tanks are fine. The sender unit was replaced a few years ago.
Everything under the bonnet is in order. The fuel injection system was recently checked. When the old girl fires up, she idles smoothly and runs perfectly.
The only thing I can think of that is causing this problem is the fuel pump. As I said earlier, after prolonged cranking, there is no smell of fuel, which does suggest a fuelling problem.
Thank you Jeroen and Wilmo for your comments. Any further views from either of you or anyone else will be most welcome.
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