Quote:
Originally Posted by arctan
Hello again Dave.
Ok. I see were you are with the '555' idea, and the surrounding circuit. Pity that the Vellermanns is astable- I knew you needed a monostable, and perhaps a relay- I wasn't reading carefully! Your pursuit of the matter is almost like my curiosity as to why my volvo needs an amount of cranking before it fires, even when hot. Not an awful amount. It's just that other cars seems to fire somewhat quicker. Starter spin speed perhaps?
And.
Missing pulse detector using - a 555! That 555 is such a versatile chip!
https://electronicsarea.com/missing-...uit-555-timer/
PS I don't think I'll make it as king of the code readers.
Regards. |
You've got exactly the problem i'm trying to solve with my "tickle the carb" circuit John. What i do at the moment is just "flick the starter" - just turn the key to the start position so the starter just begins to turn then release it - flick the key into the start position and let go which makes the ECU run the pumps for a couple of seconds. When they finish running (possibly only one pump on yours), turn the key to the start position again and it fires instantly.
Two possibilities here, either it's not priming or the "check valve" aka non-return valve on the pump outlet has gone weak/failed allowing the pressure in the fuel rail to leak back to tank via the pump. This will also cause fuel vapourisation on hot days/after a long hot run (worse when both happen!) so i'm hoping it's as simple as not priming. Anecdotal evidence from doing the flick the starter thing suggests it's simply not priming but could still be the check valve/NRV at fault.
I did try fitting an aftermarket NRV on the tank output on mine, i have the two pump set-up so the in-tank pump is at most 19psi output but can deliver 60 gallons/hour. The underbody pump runs at up to 60psi and without checking, i can't remember the flow but it needs the in-tank pump as it's not capable of enough suction to overcome the NRV if the in-tank pump has failed. I now have a replacement in-tank pump to fit to mine and if that works, i'll refit the NRV and try it again.
I've just realised we're waffling about fuel supply problems on Ellies RSR thread - sorry Ellie! <insert blushing/sorry emoji here>