T350 Cutting our when it’s Hot

T350 Cutting our when it’s Hot

Author
Discussion

martin996uk

Original Poster:

47 posts

148 months

Monday 28th May 2018
quotequote all
Hello all. I’m going to try my luck on the Speed Six section as I’m not having much luck elsewhere. My T350 is cutting out when it’s up to temperature. If I’m stuck in heavy traffic it will cut out. If I let it idle until warm it will cut out. If I leave it in the sun for a good few hours it will not start. No power to the fuel pump relay. If I open the bonnet in this situation it will start about 10 minutes later. When it cuts out when it’s been running and it’s up to temperature the fuel pumps do not prime. If you leave it 10 to 15 minutes it will start. Off you go, get caught In more traffic, it will cut out. Again and again. The fuel pump relay is red hot at this stage. So far I have bought two new fuel pump relays. I have bought and installed a new fuse box. I’ve changed the HT leads. I’ve bought six new spark plugs. I’ve re-earthed both fuel pumps to a decent earth. I’ve put a new crankshaft sensor in. I’ve done a voltage drop test which gave me ridiculous readings. 0.8 volts on the positive side and an unbelievable 270 volts on the negative side. On a 12 volt system. I should be getting readings of 0.5 volts on both the positive side and the negative side. I’ve done ten voltage drop tests. All achieving the same results. I’m either doing something wrong or something is seriously wrong. Anyway, I’m not too sure where to go from here. I’m at a loss. Worst case scenario is that the ECU is failing and that is VERY expensive. Does anybody have any ideas as to what my problem could be?

Edited by martin996uk on Monday 28th May 22:04

martin996uk

Original Poster:

47 posts

148 months

Wednesday 30th May 2018
quotequote all
Is there a test I can do on the fuel pump to definitely diagnose the problem as the fuel pump? The problem only happens when the engine is up to temperature.

martin996uk

Original Poster:

47 posts

148 months

Wednesday 30th May 2018
quotequote all
My engine temperature seems normal. The first fan cuts in at about 85/86 degrees and the second fan cuts in at about 91 degrees. It never goes higher than that. As for fuel, I’ve only ever put in Shell V Power for the last 5 years. How would you sort out or check a vapor lock?

Edited by martin996uk on Wednesday 30th May 14:01

martin996uk

Original Poster:

47 posts

148 months

Thursday 31st May 2018
quotequote all
My power steering is wired up with the fuel pumps.