1993 850 non-turbo Flooding

Tolsester · Post by **Tolsester** » 23 Apr 2025, 21:44

Occasionally, like once every 2-3 months of months, the engine will flood when trying to start.

It always goes like this: Crank, fires, let off of the key, engine dies. This always means it will take me forever to get it started again... I'll either wear down the battery trying to get it started and then recharge, or I need to get a jump start so I can pump air through the engine to dry things out. Then when it starts I have to keep the revs up for about 30 seconds to a minute or it will die again.

When it does finally start, it will fire intermittently as the revs build until the engine can sustain itself without cranking.

This morning I was home alone, so battery charging it was. After the second failed attempt, I removed all the plugs and let the engine air out while the battery was charging.

That got it started, but I still had to keep the revs up while the engine got going.

Other than the typical plugs and wires, what else should I check? (122k miles)

The plugs don't look worn at all (OEM Volvo - original? idk), but looks like I might have some oil in the combustion chamber. PCV?

Post by **misha** » 24 Apr 2025, 01:12

Bad maf or ect...or their wiring.
Read the codes...obdI is under the hood.
All you need is a pencil and piece of paper to write down the codes.

Post by **Clemens** » 25 Apr 2025, 02:08

Do you start the engine with or without giving it some throttle? I usually hit the gas right after cranking. My wife doesn't do that, and I have the impression she stalled/flooded our old 94 10V non turbo alot more frequently than I did.

454cid · Post by **454cid** » 25 Apr 2025, 09:51

Maybe check fuel pressure along with codes.

Vova585 · Post by **Vova585** » 25 Apr 2025, 10:30

I agree with the idea of checking fuel pressure. I am suspecting leaky fuel injector or backflow valve next to the tank. I think 850 have a service port which is easy to access so I would start there. Go to harbor freight and get yourself a fuel pressure gauge(or rent from zone or advance if available). Wear glasses and connect gauge to the port. Prime fuel pump several times and check for leaks around connector. If all dry-start car and let it normalize. Check the pressure while running(around 3.5 bars should be norm). Turn engine off and check pressure. (Should drop to 1-1.5 bar and stay there). Leave the car for 4-6 hours and check pressure. If 0psi-either leaky injector or backflow. Start there and keep us posted.

Post by **abscate** » 26 Apr 2025, 00:04

If the engine coolant temperature sensor is old, bad wiring, or aftermarket often these engines will flood on starting. Have a good look at that and measure with an ohmeter when cold. Specs are here in the Fora.

Cap and rotor are wear items and should be inspected, nice and shiny and clean on all brass parts