flooding/overfueling
 

hi guys, my son has purchased a 1989 240 gl, b200 engine on Injection. The car was in daily use up till 5 years ago until the then owner purchased a torslander? and this car then sat on his drive till we collected it. we were told that the fuel pump was faulty due to it being left and that it had been replaced with another, couldn't get any life out of either so type in the code from the original into "eBay" and got a replacement, fitted it but won't start. Pulled the plugs out and there're literally dripping with fuel, checked the spark, good etc still no go. We can get it to start by disconnecting the power to the pump, it starts instantly so then we reconnect the pump and it runs rough below 3k. So could this be something wrong with the injection system or is the pump pumping to much? cheers in advance

Sounds like k-jetronic?, I would say a good start would be to make sure the system is running at 70psi and basics like injector seals are good, have you managed to get the engine up to normal operating temperature?

It could be a bad thermo time switch and cold start injector causing too much fuel to flow in, try disconnecting the cold start injector, let it squirt into a bottle and see what happens when starting

Not sure which injection system is fitted to my old Volvo, but last year it ran very rough then finally stopped. The AA man diagnosed overfuelling (like yours) and a Volvo garage found a temperature sensor wasn't functioning - it was stuck on "full choke". They also suggested disconnecting the cold-start, like above, if it happened again, which is worth remembering as I haven't run the car for ages so it might be reluctant.....

P

I've just had the same issue with my 744, B200F with LH2.4, the fault was with the Coolant Temperature Sensor-it's IMPERATIVE that you use the Bosch iteration of the sensor as a replacement, the cheap pattern sensors are rubbish. The ECU needs an accurate read from the sensor to govern fuelling correctly, the cheap pattern sensors don't provide what the ECU needs reliably...Bosch is the only way.

thanks guys for the replies we're going to try them i'll let you know whatbthe outcome is cheers

Flooding with LH ignition?


Have you tried exactly this. Push the accelerator to the floor and hold it there, turn the key to start and keep starting, relax the accelerator only when the engine starts.

This allegedly sends suitable signals in the electronics so that flooding can clear. It is essential to floor the accelerator BEFORE trying to start the engine and keep it floored until the engine starts..

Less red blooded or inadequately timed accelerator techniques give the wrong signals and cause more flooding.

Allegedly.



Or you might have a faulty component &c.


.

I've found the flooded start procedure works on normal circumstances, but not if the CTS is faulty...I tried it multiple times over two days with my 744 but it wouldn't play ball at all until the CTS was replaced. Has been starting and running perfectly since, thankfully!

Does anybody out there know of any good alternative to the Bosch sensors, because since it appears Bosch doesn't make the original ones anymore (or at least for the LH 2.4 system). I tried 4 aftermarket ones and my volvo wouldn't even start with that rubish. Buying used Bosch sensors doesn't make so much sense. Suggestions anyone?

If it's Kjet, I can only think of two things.

The cold start injector is dumping too much into the intake or failing to shut off. The simple test is to unplug the connector and see if it helps. Note that this isn't controlled by the coolant temperature sensor, it's a separate temperature switch located further aft on the head. Pull it out, attach a meter to the pins to check for continuity. Then stick it in a cup of boiling water. The connection should open circuit as the sensor heats up.

The other thing it could be is a sticking plunger in the metering head. If this sticks in a high location then it will dose the fuel as if the throttle is open.

Get a long 3mm Allen key and put it into the mixture screw next to the big rubber air sock, and use at a mild angle it to lift the adjustment screw and as such the whole air plate up and down. If it's sticking you will either feel resistance and or a "tap" as the air plate hits the plunger. If working properly it should follow very smoothly and quietly.

It's worth also checking the air plate itself to make sure it isn't fouling on anything and sticking in a high position.