Low fuel pressure = starting problem?
- Thread starter willbur
- Start date
yes 30 psi should be able to start the car. The fuel delivery will be lower but not 40% lower like the pressures would suggest. I'd expect closer to 15% less fuel but cars start very rich anyway.
I agree with @Jetronic that 30 psi should be enough to start the Corolla. What year/engine is your neighbor's Corolla?
To determine if it is a fuel delivery issue, he can spray starting fluid or carburetor cleaner (e.g., Gumout, Berryman's B12 Chemtool, Super Tech, etc.) into the air filter intake plenum for ~5 seconds and immediately crank the engine. If it starts and runs for a short period, there is a problem with fuel delivery. If it doesn't start, it is most likely an ignition (no spark) or timing issue (maybe Crankshaft Position Sensor). I would not expect compression problems unless something mechanically notable happened (e.g., broken timing belt/chain, bent valves).
To determine if it is a fuel delivery issue, he can spray starting fluid or carburetor cleaner (e.g., Gumout, Berryman's B12 Chemtool, Super Tech, etc.) into the air filter intake plenum for ~5 seconds and immediately crank the engine. If it starts and runs for a short period, there is a problem with fuel delivery. If it doesn't start, it is most likely an ignition (no spark) or timing issue (maybe Crankshaft Position Sensor). I would not expect compression problems unless something mechanically notable happened (e.g., broken timing belt/chain, bent valves).
Thanks-
Later on he sprayed some starter fluid into an intake point and it did not start or sputter. Seemed odd. He replaced pump and tells me that worked. Still seemed odd. I don't like to play Joe Mechanic, so I didn't ask any questions. Got my interest up, that's all
Never had a car with starter fluid not try to start if the issue was no fuel... They might stall again in a a second but they did try to start...
I'm in disagreement with others. In some cases fuel injectors can dribble fuel out instead of a fine mist if the pressure is too low, not allowing starting. This could come in combination with a little varnish buildup in the injectors, so I might put some Techron in the next tank of gas, and if it's not driven a lot so the fuel gets old, drive more or put less fuel in at a time so it isn't sitting so long, especially if there's ethanol in it.
As far as not starting with a starter fluid spray, it could depend on what it was, how much, and what this "intake point" was. I'd be spraying right after the air filter box, if not at the throttle body, before and while someone else was cranking the starter.
Regardless, if it's repeatable to measure only 30 PSI on a 50PSI system, fuel delivery needed addressed anyway, so no point in waiting to do that, but then the question is whether it's pump, clogged filter, electrical delivery problem, etc.
As far as not starting with a starter fluid spray, it could depend on what it was, how much, and what this "intake point" was. I'd be spraying right after the air filter box, if not at the throttle body, before and while someone else was cranking the starter.
Regardless, if it's repeatable to measure only 30 PSI on a 50PSI system, fuel delivery needed addressed anyway, so no point in waiting to do that, but then the question is whether it's pump, clogged filter, electrical delivery problem, etc.
Last edited:
