Poor running K Jet

[Joe of Loath]

The more you know. I came back and found it disconnected so I must have forgotten to put it back on, meaning it should go even better now I've put it back? I don't think K-jet has an EZK (that's LH2.x isn't it?) but there's a box under the dashboard that does all the black magic stuff.

I was dubious about cleaners in cans, but it seems squirting solvents through gummed up parts *does* work.

[Laird Scooby]

It should indeed go better once you refit it, yes. Mine was hanging off for a long while on my last 740GLE and i thought i'd plugged a turbo in when i refitted it!

I'm not sure EZK is the right set of letters but it's something along those lines - i know the L-Jetronic usually used the mechanical advance on the distributors and the LH-Jetronic i believe has the ignition advance built in to the main fuel ECU so it's virtually a complete, stand-alone engine management system.

Whichever way it is in fact, it's a black box under the dash and controls the ignition timing and advance. Without that vacuum hose connected there will be no advance which will hit drivability, economy and power.

[Joe of Loath]

Posting just in case anyone has any similar problems - I took it to the car wash and all was running fine. Drove off and it stalled in the middle of the road (just as I was trying to nip through a gap in the traffic that had stopped momentarily - doh!)

Pushed it into the conveniently placed pub car park nearby and tried some things - it would turn over but not fire, or fire but not quite catch. Occasionally we'd get it running, and the engine would run for a while at medium revs then splutter and die. We had more luck bump starting it but it wouldn't run for long.

Went to the pub for lunch, walked home and picked up some tools. My suspicion (confirmed by some helpful folks on the Facebook group) was that there was gunk in the IAC that's bolted to the rocker cover, so I took the top hose off and squirted some of my magic degunking juice in. What do you know, it fired right up.

I also think I've found the source of my poor idle - the idle speed is too high, and someone previously has screwed in the air bypass knob to slow it down, meaning it's running very rich, especially when cold (which is when I have the most problems). Going to have a fiddle and try get it running better, hopefully I can improve the low end pickup. After all this it's going to need to go to someone with a CO meter, because it was tuned about nine months ago and been messed with a lot since then.

First though, I have to machine some new alternator bushings, because I have a big stack of Delrin I pinched from the bins at work (thanks new job!) and don't want to pay £30 for poly bushes.

[Joe of Loath]

Took it to get washed again today... Exactly the same symptoms. Started fine, pulled out of the car wash and it started to run on two or even one cylinders at idle, but fine if I gave it some revs. As I drove down the road it got worse until it conked out. Thankfully I went to the car wash down the street, so it was just a quick push away. I got it started a couple of times on the driveway but it wouldn't run for long enough to park it, so I had to park it with lots of elbow grease.

Water in the distributor, would you say? Why has it suddenly stared doing this, and what can I do to stop it happening in future?

[Clan]

Originally Posted by Joe of Loath

Took it to get washed again today... Exactly the same symptoms. Started fine, pulled out of the car wash and it started to run on two or even one cylinders at idle, but fine if I gave it some revs. As I drove down the road it got worse until it conked out. Thankfully I went to the car wash down the street, so it was just a quick push away. I got it started a couple of times on the driveway but it wouldn't run for long enough to park it, so I had to park it with lots of elbow grease.

Water in the distributor, would you say? Why has it suddenly stared doing this, and what can I do to stop it happening in future?

or over the plug leads ?
When these cars were current i always washed the engine off after a service , There were never any ill effects ... The standard waterproofing is 100% so what has been changed ?
Where is the water coming from ? Did you see water over the cap or leads ?do you use the screen wash coming out of the car wash ? If so the leaking T valve under the bonnet can spray the cap with water , or the waterproofing strip along the rear edge of the bonnet might be missing or have gaps ...

what is the distributor cap like ? Is it volvo ? Is it non volvo with the non-lacquered inside ? Non genuine plug leads ? The best type are the old blue wire ones ...If you can find any used ones . I remember the coil HT Lead causing starting problems sometimes even in dry conditions . Take it off , reverse it and it would start . Also the flywheel impulse sensor wires can rot out of view ..water would not affect this though .

[Donesy]

Not sure if it's your K-jet that's causing the problem but when I was struggling with my Capri these two articles totally saved my bacon and convinced me Kjet was the most beautiful system I had ever come across. effin' work of art.

Totally mechanical and reliable and daybreak. it's usually the cold-start and warm-up compensation systems that give trouble. either not working or failing to shut off.

https://www.youtube.com/watch?v=a4fJAfXYxWk

http://www.zeepoort.nl/jetronic/K-Je...eshooting.html

Dave

[Joe of Loath]

Originally Posted by Clan

or over the plug leads ?
When these cars were current i always washed the engine off after a service , There were never any ill effects ... The standard waterproofing is 100% so what has been changed ?
Where is the water coming from ? Did you see water over the cap or leads ?do you use the screen wash coming out of the car wash ? If so the leaking T valve under the bonnet can spray the cap with water , or the waterproofing strip along the rear edge of the bonnet might be missing or have gaps ...

what is the distributor cap like ? Is it volvo ? Is it non volvo with the non-lacquered inside ? Non genuine plug leads ? The best type are the old blue wire ones ...If you can find any used ones . I remember the coil HT Lead causing starting problems sometimes even in dry conditions . Take it off , reverse it and it would start . Also the flywheel impulse sensor wires can rot out of view ..water would not affect this though .

Sorry for the late response, was away on holiday, busy with new job etc.

There were some drips down the firewall and on/near the distributor, I can't confirm that's what caused the problem but it ran better when dry. Didn't use the screen wash, but definitely missing one of the seals (there are two correct?) one was hanging loose and tatty so threw it away.

Distributor isn't Volvo - I think it's Bosch but can't remember. Looked almost like new about 2000 miles ago when I had it off. I've posted a photo.

HT leads are black and IIRC unbranded.

I think I have multiple issues here, I think I have a weak or intermittently weak spark, plus fuelling issues. My first step is to remove all the K-jet parts, clean them up with carb cleaner inside and out (not going to disassemble any units however), then re-assemble with new vacuum hoses, HT leads and plugs. If I still have issues I'll get a rebuild kit, or if I'm feeling flush, ship the parts off for rebuild and calibration. I do like the K-jet system and when it works well it drives nicely, so I think it's worth getting the system running. If the car dies elsewhere I can even move the K-jet to a new shell.

Thanks!

[Clan]

Originally Posted by Joe of Loath

Sorry for the late response, was away on holiday, busy with new job etc.

There were some drips down the firewall and on/near the distributor, I can't confirm that's what caused the problem but it ran better when dry. Didn't use the screen wash, but definitely missing one of the seals (there are two correct?) one was hanging loose and tatty so threw it away.

Distributor isn't Volvo - I think it's Bosch but can't remember. Looked almost like new about 2000 miles ago when I had it off. I've posted a photo.

HT leads are black and IIRC unbranded.

I think I have multiple issues here, I think I have a weak or intermittently weak spark, plus fuelling issues. My first step is to remove all the K-jet parts, clean them up with carb cleaner inside and out (not going to disassemble any units however), then re-assemble with new vacuum hoses, HT leads and plugs. If I still have issues I'll get a rebuild kit, or if I'm feeling flush, ship the parts off for rebuild and calibration. I do like the K-jet system and when it works well it drives nicely, so I think it's worth getting the system running. If the car dies elsewhere I can even move the K-jet to a new shell.

Thanks!

It is hard to tell which cap that is , The volvo Bosch one has a shiny Lacquer on the inside , The Bosch one is dull finish . Anyway there do not seem to be any sparking burns there so just clean it up ...

[Joe of Loath]

Guess which injectors were in my car...

Have I found the issue? (It's probably one of many). Surprised it ran at all to be honest.

[Laird Scooby]

Looks very like it was leaking air past the "O" ring Joe - even renewing the "O" rings (about £16 for all 8 from Volvo) improved my last one no end.

A bit of Vaseline or similar (silicon grease works well) on the "O" rings as you refit them helps them to find their gas-tight position and slip in that bit easier.