1977 244 hard starting (intermittent)

Matt35

Hi all. Recently purchased a 77 244 DL. More recently, it's been intermittently hard to start. Doesn't appear to have much rhyme or reason, but randomly, it's wound over and doesn't fire until you put your foot flat to the floor. This happens randomly and the rest of the time It seems to start perfectly fine. Once running it appears to be ok, and gets along well. If anyone has any advice as to what to check, it would be greatly appreciated!

ramrod

How is the idle once it starts?

Does it change much when cold to warm to hot?

Matt35

ramrod I would say it's a little unstable when it starts cold. But once warm, it might settle down a bit lower. I'll have to pay attention

Major Ledfoot

Is this engine a carby (B21A) or K-Jet (B21E) and is it the original engine for the car?

Matt35

Major Ledfoot hey mate . It's the b21 K jet.. I believe it is original, it only has an indicated 150,000k on the clock

jamesinc

Hard starts sometimes mean the fuel system is losing prime due to either an issue with the return spring in the fuel distributor, or a faulty check valve on the main pump outlet, or possibly an issue with the accumulator. One test you could do before a cold start is to jumper the fuel pumps for a few seconds to prime the system, then try starting it and see if you notice any change in behaviour.

Matt35

jamesinc thanks mate. I'll have to go digging. Is there any literature on troubleshooting the fuel system? How many litres per minute I should be expecting etc? I was thinking it may be a blocked fuel breather but so far removing the fuel cap isn't helping.

Major Ledfoot

Matt35 Is there any literature on troubleshooting the fuel system?

Plenty.

https://ozvolvo.org/archive/ is your friend. And these.....

Volvo/240 Green Books/2_23 tp30454 CI System .pdf
Volvo/240 Green Books/2_24 TP12044-1_ci_fuel_injection_fault_tracing.pdf
Volvo/240 Green Books/2_25 TP30363-2_cis_system_repairs.pdf

...are your BFFs.

PS: Being a 77, you may not have an in-tank pump - if the main fuel pump and accumulator sits on a bracket mounted on the LH side of the tank just behind the LH rear wheel, I'm betting you won't. That means you'll have the old style tank with internal plumbing, which is prone to failure (corrosion) and it may also likely have a tank filter too (big plug with a 10mm square socket hole).

You mentioned suspecting the breather system... funny, that; there's a US service bulletin since US cars had a retrofit on these tanks due to that very issue causing vapor lock.

(thanks to Hi Performance Auto for the pdf below)

sb-grp24-no17-fuel-tank-74-78.pdf

5MB

Matt35

Major Ledfoot Thanks very much for all of that info! I haven't looked that closely, but there is a fuel pump beside the driveshaft just forward of the rear wheel ( I was replacing the trans mount the other day). I'll be getting a new fuel filter tomorrow, check the vaccum system and maybe pull the fuel cap off when it won't start next time to see if it's ending up with a vapour lock when left sitting for a while.

ramrod

One very important detail, drain the fuel tank (you’ll need to make a suitable shaped square tool) and examine the fuel and the filter attached to the drain plug

Any sign of rust or dirt, the same contamination will have compromised the rest of the highly sensitive mechanical kjet fuel injection components

Matt35

ramrod I will drain it on the weekend. I am concerned that we might find some nasty in there! Hopefully not! Are any components available anymore if needed for the fuel system?

jamesinc

Matt35 yes parts availability is good, you will be able to get parts for pretty much anything although often you have to order them from overseas.

You don't need to drain the tank, just remove the sender and peer in through the top with a torch, fuel is pretty much transparent, if there is debris in the tank you will be able to see it sitting at the bottom, even with fuel in the tank. You'll also be able to see what shape the filter sock is in.

ramrod

The kjet mechanical fuel system components are specialised.

The professionals who repair them were old when these cars were new, so you can wonder how many of them are still around, I know of two in this country. Many more overseas

You always have to start projects like these with an open mind and always check the basics before diving deep into the unknown, you could easily spend much much more than the car is worth just on the fuel system and engine restoration parts but at the end you’ll have a completed and perfecting working car.

Get back to us on the contents of the fuel tank, fuel filters, injectors may need servicing, then you have ignition system components, all of the little things attended to add up to get an engine working as it should

Matt35

Thanks all for your insights. I'll make sure I keep everyone updated as to what I find on Saturday when I get a moment to pull it apart and see what I can find

Matt35

Ok all. Finally managed to get a look at the Volvo. Changed the fuel filter ( must be original, lots of rusty fuel in the inlet end) but the outlet was nice and clean. Changed the plugs, set the timing, checked the cold start injector. Car starts ok now but runs on maybe three cylinders until you give it a few revs. Going down the path of dirty injectors. Anyone know where to source new orings for the injectors in Aus? Thanks in advance

jamesinc

Matt35 I'm not sure who would have them on hand, Berry Motor Group might, and they post Australia-wide. If you call and ask for Mark @iceton1975 he can possibly sort you out.

I'm pretty sure I have spares, I should have a heap of spares of the fat donut o-ring that goes on the injector, and probably the thin o-ring that goes around the plastic seat that the injector sits in. Send me a DM if interested.

If you have o-ring issues then hitting the injectors with some ether or brake cleaner while it runs should tell you, if it can suck the fluid past the o-rings the motor will pick up and you know there's a leak.

But it might be simpler to just throw parts at it, the original injectors will be pretty worn, they have internal springs that fatigue over time. You can get a refresh kit like https://www.ipdusa.com/products/21825/K-Jet-Injector-Revival-Kit-240-76-85-for-Volvo-IPD-Kit-Builder-K21825 or you can just buy the injectors themselves which are Bosch 0437502015 (your original injectors are probably ending 007 but these are NLA, you can run the 015 just fine it won't change your fuel mixture).