Starting problem on '98 S-70

[niles]

Must crank 5-6 revolutions before it starts. Used to start at turn of key. Recent fuel filter change, spark plugs, wires, distributer cap and rotor Runs smooth once started.

[Krons]

I’d check fuel pressure.

[jreed]

Agreed with above. Do you hear the fuel pump turning on and priming when you turn the key to run (before starting)?

[Vova585]

Most likely suspect is low fuel pressure. It can be due to the fact that backflow preventer valve is weak and pressure just dropps to 0psi after you turned off the car and let is stay for an hour or so. Could be fuel pressure regulator being at fault. Could be weak pump or weak Amp at the pump. If I remember correctly the 98 still had fuel pressure test port at injector rail. Rent fuel pressure tester from local store and connect it to the car. Start the car and make sure it runs for 3-4 minutes. See what the pressure shows and of it is steady( probably around 3-3.5bar), try to add "gas" rapidly and make sure the pressure still stays relatively stable and not dropping to 1-2 bar. Give car 1 minute to idle and turn the engine off without removing the gage. See what the pressure is. It will drop from 3-3.5bar to about 1.5 bar or so and should stay there. Not 0. If the pressure rapidly falls to 0-pressure regulator, backflow valve, leaky injector. If the pressure stays about 1bar after 1 hour or so, prime the system with turning the key position 2 so the pump will kick in temporarily. Check the pressure. It should be back around 3-3.5bar
Let us know what is going on after you will do fuel pressure test.

[niles]

thank you for your detailed reply. Once it warms up I'll do the tests and let you know. Niles