wierd starting problem

[me217]

hey i have a 1992 sierra with 1.6l mpfi vitara engine in it. its bin in the car for ova a year. and only recently i've bin having problems starting it.
it starts fine when its cold and if it has only just bin shut off. but if it sits for more the 15 mins or so after its warmed up it fires stalls and then works fine the second time.
it also plays up after sitting in the sun all day, when i go to start it, it winds for ages (10 - 15 secs) b4 it finally fires.

can any one help its getting really annoying.

me217

[blutruck]

G,day me217
When you are having this problem, try turning the key to the ignition position (second click) and leaving it there for 5 seconds before trying to start the engine. If this fixes the problem, chances are you are slowly loosing fuel pressure when the engine isnt running, either from the fuel pump bleeding back in to the tank, or from the fuel pressure regulator bleeding through the vacuum line and in to the inlet manifold, or a leak at one or all of the injectors.
After the engine has been running, pull the small vacuum line off the fuel pressure regulator and check if it is wet with fuel, if not check around the injectors where they seal to the fuel rail for wetness or stains, if not, Id say more than likely it is your fuel pump not holding pressure.
If you have access to a fuel pressure gauge, this is an easy way to find out.
Good luck
Mark

[me217]

my fuel pressure regulator was leaking a couple of months ago causing a similar problem but ive checked it recently and its dry. i remember looking every where for a new regulator but no one had them. even suzuki couldn't get them for me. but ill try this tomoro after work. but i dont need to turn the key i have my pump hooked up to a seperate switch as the relay for the fuel pump died ages ago, so i jumped that then something else stopped working causing the fuel pump not to work so i got annoyed with it one night and wired up a over ride switch.

me217

[blutruck]

Just flick the switch and wait for 5 or 10 seconds before starting the engine to prime the fuel pressure and if it starts without hesitation then were heading in the right direction, if this doesnt help you might want to check for fault codes.
Did you wire in the diagnostic curcuit?

[me217]

i did but the bulb blew lol prob from showing up the vss error all the time. and yes the vss is installed just didnt work, prob installed wrong. and i havnt gotten round to fixing either.

mr217