1978 245 GLE injection starting problem

[Peter222]

Originally Posted by Clifford Pope

I have been confused about that too. You have probably been thinking that "injection" meant that fuel is squirted straight into the cylinder, like on a traditional diesel.

That's exactly what I was thinking, now I get it.

Peter

[Bugjam1999]

This website is another useful source of manuals - just type what you're looking for into the search bar:

https://ozvolvo.org/archive/

Cheers

[Peter222]

I have now determined that the cold start injector is faulty. During cranking, pressurised fuel gets to the banjo. 12V is present at the connector showing that the wiring and thermo time switch are intact. Yet nothing comes out at the nozzle end. I presume the solenoid winding has burnt out or otherwise lost connection.

Is this injector something that can be stripped and repaired?

I'm informed by various dealers that this (part no 462865, according to the VIN, which shows it's a 1979 model) is no longer available. Can anyone possibly sell me one or suggest breakers that might specialise in Volvos?

Peter

[Othen]

Originally Posted by Peter222

I have now determined that the cold start injector is faulty. During cranking, pressurised fuel gets to the banjo. 12V is present at the connector showing that the wiring and thermo time switch are intact. Yet nothing comes out at the nozzle end. I presume the solenoid winding has burnt out or otherwise lost connection.

Is this injector something that can be stripped and repaired?

I'm informed by various dealers that this (part no 462865, according to the VIN, which shows it's a 1979 model) is no longer available. Can anyone possibly sell me one or suggest breakers that might specialise in Volvos?

Peter

It seems to be still available from Scandcar:

https://classic-volvo.com/catalog/pr...28e-for-volvo/

... it is more than a little bit expensive though! It might be worth looking for one for another motor that fits (I did that with the anti-dieseling solenoid on the RB, one from a 1970s VW Beetle fitted perfectly and cost 15% of the price).

Alan

[Mark1Stu]

I’ve had similar problems with my 240 project which had been off the road for 13 years. While it’s an ‘88 year 2 litre, it has the K-jet set up.

Basically, when cold, it would mostly fire up perfectly then die without idling. If I revved it from start, it would pop a little and run rough until it got some warmth in it, then progressively smooth out.

The most improvements have been cleaning the idle valve (which was sticky) and replacing the non original coil - for a higher output OE one - so checking and replacing tired ignition components like plugs, leads, cap, rotor arm etc would make sense.

I previously squirted WD40 over the injector seals and they were fine (didn’t suck the WD40, or increase revs). Ditto the inlet manifold gasket and all pipe work to and from it. No air leaks.

With it still not idling properly from cold, I was wondering whether the thermal timer sensor was faulty ie not operating the cold start injector….but haven't actually tested either. Worth noting, the cold start injector operation and duration is linked to temp, so it wouldn’t necessarily spray fuel on a warm day (unless I’m mistaken).

The Haynes manual states to check the fuel relay if the thermal timer/cold start isn’t working properly - as it’s powered from it. I have a new fuel relay, so will swap it over to check.

However, I’m actually coming to the view it won’t idle from cold (and sometimes not immediately start) due to sticky/partially blocked main injectors - in particular they aren’t all fully shutting off - thus draining fuel pressure in the system overnight. I think this as Ive added injector cleaner to the tank and idling performance from cold seems to be progressively better with each long engine run (I can’t use the car on the road as the mot is out). So I’d certainly suggest you add cleaner to the fuel (mine had the main fuel filter changed, new in tank pump (yours being early may not have one) and main fuel pump.

MOT this weds - so will keep you posted if it passes and after an Italian tune up!

[Mark1Stu]

Well it passed!

CO level was 0.5 and I think the MOT tester said the maximum permitted is 3.5.

So I’ve ordered a long 3mm Allen key so I can temporarily adjust the mixture screw (keeping a note on the amount of clockwise adjustment) to see if richening the mixture helps with cold start idling. If it does, I’ll get it properly adjusted with a CO meter at the MOT station.

It certainly didn’t want to idle on cold start up today until I got a little warmth in the engine (circa 20 seconds of running) and was lumpy until fully warm - then ran sweet and smooth.

[Othen]

Originally Posted by Mark1Stu

Well it passed!

CO level was 0.5 and I think the MOT tester said the maximum permitted is 3.5.

So I’ve ordered a long 3mm Allen key so I can temporarily adjust the mixture screw (keeping a note on the amount of clockwise adjustment) to see if richening the mixture helps with cold start idling. If it does, I’ll get it properly adjusted with a CO meter at the MOT station.

It certainly didn’t want to idle on cold start up today until I got a little warmth in the engine (circa 20 seconds of running) and was lumpy until fully warm - then ran sweet and smooth.

Good news!

[Mark1Stu]

I hope Peter doesn’t mind me hijacking his thread (hopefully his car’s problem is sorted…or my predicament might be of interest).

Anyhow, having driven the car post MOT, it has run well when warm but still a little lumpy when cold….and will still not idle immediately after a cold start until I keep the revs up for circa 20 seconds until some warmth gets into it.

You may remember, the CO2 fig was 0.5 at idle and the MOT man said that was very low. Well, armed with the 3mm long Allen key from Amazon, I carefully turned it clockwise (imagine the hour shorthand on a clock, I moved it no more than 1 hr) in the Air/Fuel control unit to see whether it smoothed out the running by increasing the mixture (albeit prior to getting it adjusted properly with a CO meter at a garage). Anyhow, to my surprise and disappointment, it made engine running more lumpy, and when I returned the adjustment to its previous position, it still seemed more lumpy running than on previous occasions.

I initially thought increased lumpy running following richening the mixture might accentuate a partially blocked or under performing injector, but the fact the lumpiness didn’t decrease markedly when weakening the mixture to the prior position, suggests that might not be the case?

I’m now thinking perhaps the Air/fuel control unit might be suspect. Perhaps first I should check the air sensor plate is centralised correctly (I didn’t press down unduly on the Allen key, but perhaps simply adjusting the mixture has moved it).

What do others think could be the cause/ next step? Between each step above, the engine was subsequently revved up (Allen key removed) to try and settle the idling.

Currently I’m trying to avoid either spending £££ going to a FI specialist, or trying to test the injectors and fuels distributor function myself (based on Haynes). Being a carburettor man!

Btw, if anyone has for sale an air/fuel control unit, set of injectors and warm up unit (all working) for an ‘88 B200E I might be keen!

[Peter222]

Update some days later. I'm unable to work on the car every day much as I'd like to... but made a bit of progress.

I took off the cold start injector and tested it with 12 volts. It clicked, but was completely clogged up, couldn't blow through it. Overnight in warm alcohol ultrasonic bath... opened up with 12V. Injector sorted.

But when it was fitted back on, the engine still wouldn't start. Problem traced to thermo time switch, which was open circuit on the relay side. I shorted this out temporarily and...

Engine started instantly every time. Great. But...

Every time it started, it would falter and stop within a couple of seconds. So now I'm perplexed again. Control pressure regulator? Warm up regulator? There's certainly fresh fuel in the tank.

Here is a very short video I made showing the engine stopping after starting.

Again, any thoughts would be appreciated.

Thanks
Peter

[Laird Scooby]

Originally Posted by Peter222

I really feel I've joined a knowledgable and friendly community here. Thanks a lot to everybody for all information so far supplied.

I've had injection vehicles before but mostly diesel, and in any case nothing has ever needed to be done to any of the injection systems. This K-Jetronic is rather complicated and I'm trying to educate myself so that whatever I do, I properly understand what I'm doing.

I am thoroughly confused by this continuous injection business. I understand that each injector squirts fuel 4 times per cycle, so it's injecting not only during induction but also during compression, combustion and exhaust. Is this right? It seems terribly wasteful of fuel yet it can't be or nobody would use the system.

There's been a lot of questionable information bandied about through this thread. There's also been some good advice.

A brief explanation of the K-Jet system - when the fuel pumps are running (that's right, there are 2!) and air is flowing into the engine, the fuel pressure in the fuel distributor increases to the point where it overcomes the injectors squirt/no-squirt point (~38-52psi) and fuel starts to flow through all 4 injectors. The "K" in K-Jetronic stands for "Kontinuierlich" which is German for "Continuously". Alan may correct my German spelling, it's a while since i used my German!

As airflow into the engine increases, the more it deflects the "paddle" in the fuel distributor which in turn increases the injection pressure - this is therefore making the injection pressure proportional to engine load. As the injector size is a constant you can see this will alter the amount of fuel injected proprtional to load.

That's it in a nutshell, however there are a few more things to check. First is the Auxiliary Air Valve (AAV) which others have mentioned. This should be completely open when cold and the ignition hasn't been switched on. Pull the hoses off it and look through, you should see a circle of daylight. While the hoses are off, give it a squirt of carburettor and air intake cleaner. While refitting the hoses, ensure they are a snug fit with no possibility to leak.

Once the engine is warm remove the hose on the air filter side of the AAV and use a torch to look into the AAV to confirm it has closed - while you have the hose off, give it a couple more squirts of carb cleaner.

Next is the idle switch on the throttle body. When the throttle is closed (ie at idle position) the microswitch should be made. It's possible some numpty has adjusted the throttle butterfly base position to change the idle speed when it should never be touched at all.

Next, the thermotime switch. If engine temperature is below a certain point (can't remember the exact temp just now) this switch will close switching the cold start injector on for a maximum of 8 seconds during cranking/initial start-up.
You suggest this switch isn't working, they rarely fail but it can happen. Check the connections and also the earth connection for it, cleaning the connections if needed.

Also worth cleaning the PCV system including the stub on the inlet manifold that provides vacuum for the PCV system - use carb cleaner to clean the insides of the various parts and stubs.

Last but not least, the coil looks filthy. Clean it and check/tighten/clean the LT connections and also check the inside of the HT connection is clean and bright, not furred up with corrosion. While on the HT side of things, remove, inspect, clean and regap the plugs. They should be 0.65-0.7mm (0.025-0.028"), if in doubt, renew them but be aware that new NGK plugs come pre-gapped at 0.9mm so WILL need closing slightly. If memory serves, should be BCPR6ES plugs for yours.

This little lot should get you running but also worth renewing the injector "O" rings, all 8 of them! Chances are, they're leaking but either way, at probably 44 years old, are likely to be perished, split and not working very well as seals. Will cost about £17 for all 8 "O" rings from Volvo.

Try some Carlube Injector cleaner, i think Hellfrauds sell it, i know they used to sell the diesel version.

https://www.halfords.com/motoring/en...te-247886.html

https://www.halfords.com/motoring/en...er-247638.html

Looks like a visit to Hellfrauds is called for, they also sell Carb & Air Intake cleaner.

Let us know how you get on.