I'm pretty certain my starting issue is now solved. It's fired up over 10 times now hot and cold without a hitch. Thanks for the pointers, saves me wiring a separate ignition switch (was my next port of call).
I've just got the cooling issue to sort out now. I pulled out my temp sensor and instrument panel and bench tested it at a range of voltages between 12 and 14V. The gauge its pretty accurate; the resistance of the sensor looks nothing like the VDO literature but it works. At 14V it reads correctly all the way down to 70 degrees. I went out for a drive this afternoon and the engine was hovering around 95-100 depending on whether I was driving hard or coasting. When I got back I put my hand on the radiator top hose to find it scorching and very firm to the touch. The Rad top tank was painful to touch (and was leaking a little coolant under pressure from the cap seal). The bottom hose was at the ambient temp of the engine bay and the rad bottom tank was positively chilly. The rad didn't feel at all warm until halfway up and was only getting hot in the upper third/quarter. So it looks pretty conclusive that either the thermostat is not opening or the rad is well and truly blocked, which is pretty unlikely.
I'm just amazed that it hasn't over heated more. The DME must have been jumping in and helping with timing etc. Fixing this may therefore have a positive effect on performance too.
I've ordered a new 92C and 87C thermostat to experiment plus I'm going down to Marlin on Friday to get the louvres cut in the bonnets. Hopefully my cooling woes will soon be over
|