Won't Idle When Warm, Kangarooing.

[Ben1985]

Hi everyone, this is my first post on Club 80-90 and I somehow suspect it will not be my last. In February I briefly spoke to the very knowledgeable Kevtherev (PM) who gave me some great advice on the above problem I am having, but I now need more and wanted to share my problem with the whole Club so we can hopefully help out other people who may experience the same issue. I know this topic is well covered on the forum but each case seems to be different and I have taken a video of said problem and will definitely update the posts as we go along, including how we eventually manage to resolve it.

A brief bit of background. The van itself is a 1983 Hi-top Leisure Drive conversion with a reconditioned engine and gearbox approximately 10 years ago. It's a 1.9 but not sure if DG/DF, 5 speed manual. You knowledgeable people will be able to tell from the video. When we first got the van we took it on a nice 300 mile round motorway trip stopping off overnight after approx 150 miles. On the way back we stopped for petrol after I had been driving about 80/90 miles and after filling up she wouldn't start. She would turn over but wouldn't fire. After some persistence she eventually fired up and we got home without another hitch. I replaced the fuel filter next to the fuel tank, installed new fuel lines from the tank to the pump (also replaced pump and pushrod) and a new fuel line from the pump to the carb. All with new hose clips of course. I know began restoring her to her former glory externally and internally. It took about 4 months in total and she didn't move from her spot during this period. Once she was finished I took her for a leisurely drive to a relative about one hour there and one hour back. We made it without any problems, she was a little tappety at first but that soon went off.

Now the fun starts.... About a month later (awful weather over Christmas and January so she stayed tucked away under her cover) I took her for another run up to a different relative about 30 mins away. On the way we had to climb a steep dual carriageway, she didn't like that and almost died on me near the top. I noticed that the petrol needle was very close to empty on the way up the hill so pulled into the nearest station only a few hundred yards from the top of the dual carriageway. After filling up she started first time in the petrol station but wouldn't hold her revs and stalled immediately. I started her up again and got to the junction of the petrol station where she stalled again. This happened about another two/three times so I gave her some good revs and she decided to idle. I got to my relatives about 3 miles away with no more stalling issues. On my way home about 3/4 hours later I got to a little bridge in my local town and slowed down for oncoming traffic, and you guessed it, she stalled. She would start and fire up but would not hold the revs, she wouldn't even allow me to rev. I could turn the key and she would fire up every time but stall instantly. I couldn't move from the bridge so sat there for about 30/40 mins while she cooled down. After this time she fired up and held the revs at idle but not convincingly. I got about another 800 metres before she started kangarooing and died. There was no backfire or anything of that nature, just kangarooing and then cutting out. I got towed home from my brother. After letting her cool down for 3 hours I started her up and she ran fine, allowing me to reverse her onto my drive.

After this I got in touch with kevtherev who very kindly pointed out some things to check. This problem is definitely related to warmth, the hotter it gets the worse it gets. Here is a list of things I have done/checked with a brief explanation. All thanks to kevtherev.

1. Brake servo hose - changed for temporary piece of reinforced vacuum hose to ensure that it is complete with two new hose clips while I eliminate the problem.
2. Choke pulldown unit - pulled end off carb with top pancake off. Sucked and it moved choke flap, put tongue over end and it held the flap, released tongue and it released flap.
3. Distributor diaphragm - removed end from carb, sucked a few times holding vacuum with tongue over end, when I released tongue it released vacuum. I could suck 2/3 times before I got a really good vacuum where I couldn't suck anymore. I did hold tongue for a few minutes and it held vacuum.
4. Diaphragm at back of choke ( I believe this is secondary) - removed end from carb, sucked and it held vacuum with tongue until I released tongue.
5. Carb cleaned - Removed carb from manifold, cleaned out jets, float chamber etc with carb cleaner. Blew through jets and all seemed clear. There was a bit of crud in bottom of float chamber but I obviously cleaned all this out.
6. Carb filter - Removed little cone filter inside carb and cleaned. This was pretty nasty at the end, lots of black bits but they cleaned out.
7. Oil breather tower - Removed and cleaned, breather tower and pipe.
8. Fuel cut off solenoid - listened while partner engaged ignition and there is a definite click from that.
9. Air filter - Removed and cleaned housing. Air filter looked nearly new so re-used.
10. Vac lines - I have had the three vac lines and connectors off and tested using water, sucking, etc but they all appear solid. I am going to replace these anyway.
11. Removed distributor cap, cleaned contacts and rotor arm.
12. Removed newly installed fuel line from end of new fuel pump and blew all the way down. I could feel no restriction and could hear the tank bubbling. I only have the two filters that are supposed to be their, their. One next to the fuel tank and one inside the carb. No silly extra ones causing restrictions etc.

I have sprayed carb cleaner around manifold gaskets and all exterior of carb, vac lines etc and I can't notice any change in engine note. With regards to vac lines, if I remove the one from the back of the carb that connects to the distributor diaphragm when it is running it will stall almost instantly. If I remove the one from the back of the carb that goes to the air filter this also stalls the van. If I remove the one from the air filter box to the unit down the right hand side of the engine bay this has no effect on the engine. Not sure what that does to be honest.

After all this, I took her out on a run, got about 5 minutes up the road and I could tell she was starting to struggle to hold at idle. I decided to turn round and come back, however on my way she began kangarooing so I pulled over and she stalled. I started her up again, revved her a few times and got home (only 3 mins away) without her stalling.

One final thing to mention - I will post two links to the two videos illustrating my problem. In the first you will see that the van runs and idles roughly after the choke has come off and will not stall. I had this running for about 10 mins sat on my drive after it had warmed up and it wouldn't stall. I turned it off for 5 mins and then restarted it and this is where the second video begins with me restarting her. This time it will not idle after I have pressed the throttle. The video should explain more. Any help would be greatly appreciated because I am getting very close to ripping my hair out.

Video One - http://youtu.be/pNpTZvLj8BI" onclick="window.open(this.href);return false;
Video Two - http://youtu.be/m_ciWwJUKO4" onclick="window.open(this.href);return false;

[kevtherev]

Great story.
I think we need to see the choke operation.
Can you remove the duct on top of the carb?

It must be open 3 mm once the choke is set
And open fully in 6 to 8 mins

[project25]

Hi, Ive got one of them, I had it running sweet once, booked its MOT, but cannot get it to idle unless I manually hold the choke flap in the 3mm open position. Everybody will shout air leaks, but I have also replaced all hoses.
I will follow this closely because Ive given up and run out of hair to pull out.

[Ben1985]

Thanks for the quick response. Kevtherev, do you want me to video the choke flap with the top carb duct off from cold start and video it while it warms up?
Regards, Ben.

[BOXY]

With regards to vac lines, if I remove the one from the back of the carb that connects to the distributor diaphragm when it is running it will stall almost instantly.

I've got an Aircooled engine with a dual vac dizzie so I might be wrong on this. But if you've got a single vac dizzie isn't the vac signal there to give extra advance at high revs? Pulling the vac line off at idle shouldn't do anything to the engine / timing (as long as you put your thumb over the end of the pipe to stop in weakening the mixture). Have you got a strobe to check if the engine has been timed correctly.

[itchyfeet]

Wow usually it's 'my van won't idle any ideas whats wrong' with no expanation or even engine type, you have really explained that problem well

Thats a Pierburg Carb so assuming it's origional that's a DG with an early cooling system.

I'm thinking dizzy mechanical advance ( or is it retard can't remember), It once gave me alot of trouble cutting out and rough after van had been left unused, always started after stalling.
Eventually I found the fault by trying a squirt of spray oil in the base of the dizzy, worth go.


You seem to have focused on fuel supply which was my first thought but I can't help noticing your ignition leads look odd, may be worth changing the leads, cap and rotor arm to elimiate them, also worth noting the coil can breakdown when hot. Maybe a combination of faults.

[Ben1985]

Hi Boxy, I'm afraid I don't have a strobe to check timing and really wouldn't know what to do. I have had a quick look at the wiki for that and it all seems a bit complex. With regards to vac line. If I remove it, it definitely has a severe effect on engine when running at idle. It stalls instantly.

[Ben1985]

itchyfeet, I'm glad you like my initial post. The reason behind it was simple... I wanted to avoid a lot of standard replies people may wish to fire out and was hoping to really give you knowledgeable people an easier time. You shouldn't have to ask for basic information when I am the one that needs the help. I really appreciate you all taking time out of your day and don't want to waste any more of it than I need to.

Also kudos for the ignition lead spot. There is one that is different to the others but didn't think it would be the cause of my problem. I have considered buying a new set of leads, spark plugs, dizzy cap, coil, distributor (with vacuum advance) and changing all that to see what happens, but I didn't want to if that wasn't the problem. When you say spray oil in the base of the dizzy, do you mean remove dizzy cap, remove rotor arm and then spray oil in the base. Sorry if that's a stupid question but I want to be clear so I don't make a mess of anything.

[itchyfeet]

yep take the dizzy cap off, rotor arm and a platic cover, then you can squirt down into the base of the dizzy with spray oil and a thin tube on the spray nozzle, there are drain holes in the base and you should see any excess oil drip out.

I'd change leads, plugs cap and rotor arm, they are not so expensive, I would not change the dizzy at this stage.

Ignition timing is important , You should disconnect dizzy vac hose for the test which you can't do yet ( because it will stall) but it will give you an indication of whats going on.

beg steal or borrow a timing light, modern ones are easy just clip the 12V crock clip on the alternator +12V connecton , ground on the body and the trigger clamps around spark plug lead No1 ( RHS rear as you look at the engine) Then aim the light at the crank pulley to see when the spark is generated, Pulley has two notches a V notch on engine side and a U notch on the other, paint them with tippex first, the V notch should be central if timing is correct with dizzy vac disconected. If the mark is way one side or the other it indicates too far advanced or retarded, if it's all over the place it indicates a dizzy problem

[Ben1985]

Right, at the request of kevtherev I have now done two new videos for you all with the top of the carb off.

The first video shows it exactly as it was when I took the carb top off and how it reacts when accelerator is depressed before start up and during startup. The video continues for about 3 and a 1/2 minutes until the choke flap begins to move during warm up and it stalls. I tried to start it a few times but it just fired up and stalled which can be heard in the video. I put my phone down and managed to get her to start and idle roughly with a bit of revving and this is where the second video kicks in.

The second video continues to show the choke flap opening as the engine warms up and the rest you can see/hear for yourselves.

I'm uploading these videos as we speak so they may not have finished uploading until around 9pm but the links are there so just keep trying.

Video 1 - http://youtu.be/YuH607O3gNQ" onclick="window.open(this.href);return false;
Video 2 - http://youtu.be/73VEKp137lA" onclick="window.open(this.href);return false;

All help greatly appreciated.

[Ben1985]

Thanks itchyfeet. I am going to look into the timing. I can get a timing light off the popular auction website for about £20?? Not sure if this is any good. Should I check the timing with the dizzy vac hose connected and see what I get or will this be a waste of time? Also, I like to understand why I am doing things for my own personal benefit and to better understand how everything works so sorry for the twenty questions but just curious as to what the oil in bottom of dizzy will do?

[project25]

Hi, just veiwed your first video, this is exactly what mine is doing, sorry I havent got a solution, I hope the more experienced have. If you hold the choke flap down it will probably idle nicely.

[itchyfeet]

a cheap second hand light is fine as long as it works! Some off ebay won't

In the base of the dizzy is a mechanical advance/retard mecanism by centrifugal weights, if they get dry and corroded they stick.

don't rule out multiple faults

can't see the second vid does the flap actually open when hot?

[Ben1985]

I certainly won't rule out multiple faults. Thanks for taking the time to explain oil in dizzy situation, very good to know.

The second video of choke flap is now uploaded and it does show the choke flap opening fully to a vertical position.

Well I have two things to do now. Squirt oil in bottom of distributor and check timing.

[Ben1985]

I know everyone is focused on the idling issue but does anyone know why it starts kangarooing, its like the power disappears. These two issues appear to be connected as they both appeared at the same time. Once it does a bit of kangarooing that's it, it just cuts out.