B230E K-jet issues

Spac

1985 240GL with B230E seems to be getting too much fuel to start. Image description

In the last few days, it’s had a pretty thorough “Stage Zero”;
Fuel tank drained and filled with fresh 98 octane fuel;
Fuel lines cleaned out & new fuel filter;
Replacement in-tank and main fuel pumps;
New oil, oil filter, air filter, timing belt & tensioner, water pump, dizzy cap, spark plugs & leads, etc.

Cam and ignition timing have been triple checked.
Spark is strong and regular.

If you walk up to it cold and turn the key it will fire for a couple of seconds but not keep running.
After that, it will crank until the cows come home.

I have found that disconnecting the earth to the main fuel pump will allow it to run properly for a few seconds presumably until the fuel pressure runs out.
Interestingly, the fuel punp cuts out after a few seconds of no cranking, but removing fuses 4 & 6 doesn’t stop the main pump from working?!

Removing the fuel injectors and cranking shows clean spray pattern but they all keep squirting until the fuel pump turns off.

So I am pretty sure the fuel injectors aren’t shutting off… but I am much less sure where the problem is, or how to fix it.

I have spent 30 years studiously avoiding knowing more than the very basics about K-jet, but it seems that my luck is about to run out…

Any advice welcomed!

Inski

Try replacing the Thermo timer switch, they get stuck on and the cold start injector floods the engine.

John_Fraser

The injectors should spray continuously. CIS means continuous injection system. The injectors will spray for as lone as the fuel pump relay receives pulses from the ignition system.

The engine may be stopping because the ignition is not receiving trigger pulses from the distributor so both the spark and fuel turn off.

jamesinc

If the injectors aren't shutting off, I think I would start by inspecting/cleaning the fuel distributor, the metering pin might be stuck.

The injectors should not spray if the air metering flap is in its rest position (i.e. engine off, no airflow), even with the fuel pumps running, and they should start to spray almost the moment the flap starts lifting.

ramrod

Yes agree with James it sounds like the piston is not falling back down to the resting position, thus the injectors spray at high volume.

Have you lifted the metering plate with the pumps running?

jrc

There is a sort of order (based upon my several years of 245 ownership).

I had fuelling problems in the mid 80s w my 245. Volvo suggested replacing the entire f inj system. That inspired me to have a go myself first.

Put a new fuel filter in to start with.

You can check flow of each injector by setting them up in a rig with 4 test tubes same diameter or better 4 measuring cylinders. Will show if one cylinder is being overfuelled . Replace the injector ( I didnt need to do that)

You probably shouldn’t pull the fuel distributor apart but you can take it off its mounting and check the metering piston moves freely

At the same time replace the o ring in the piston which is the only seal! I replaced mine it cost $3. From Volvo !

At that point my 76 245M ran like a dream again! Did the same fix in my brothers 74 144 GL

If that doesn’t work there is a cold start fuel valve which may not be getting shut back because the bimetallic strip driver inside it has become fatigued. My issues were with 10-12 y old cars so we didn’t have that problem.

Major Ledfoot

@Spac - If you want to go by the book, we have a number of K-Jet Green Books in the Oz Volvo Technical Archive.

https://ozvolvo.org/archive/

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