More starting / running problems - possibly fuel related?

I suffered a similar problem to Markwon with his fuel system / ignition woes here:


http://portal.campaignregister.co.uk/modules.php?name=Forums&file=viewtopic&t=432&postdays=0&postorder=asc&start=30

…… but thought its probably better dealing with this in a seperate thread so here goes…

This happened to me last night and the car has been running absolutely fine up until this, used pretty much every day. Went out to drop a film back to the local Blockbuster and got there fine. Came out, started her up no problems, turned the car round, heading down the raod for about a minute and the engine just dies / stalls.

Pull over to the side of the road and try turning it over - catches once then dies. After that just turns over and doesn't catch at all.

Breakdown guy comes out, cleans the contacts inside the dizzy cap and checks the spark from the plugs - both look fine (strong blue spark). Manages to briefly start it several times by giving it loads of gas, but it just keeps dying after running for about 5-10 secs.

He loosens the main fuel line to the metering head to check fuel coming through OK - and that seems to be fine.

Eventually he helps me limp it the mile or two home by keeping the revs sky high (painful).

He suspected a fuel system problem - either a blockage or some fault getting enough fuel to the engine.

I don't think its an air leak as a lot of the rubber pipework was replaced a few months ago and all looks sound. Battery is a new Bosch one bought only 2 months ago and seems fine.

I am hoping it is something simple, and we are not into metering head territory here  :cry: . Fuel filter was changed about 6 months ago.

Are there any easy tests I can do to narrow down the likely cause? If its a fuel delivery problem will using prowlers injector test setup with the bottles tell me?

I am going to jack the car up and check the integrity of the filler neck (although I think this should be OK). The Fuel pipes under the car have seen better days though. Is there an easy way to tell if crud is getting into the fuel system (filter examination)?

Any help appreciated as I am now effectively carless until I can sort this out  :roll: . I know older cars take more TLC, but I am at a bit of a low point with my car at the moment. Its getting to the stage where I really can't rely on it as a day to day car. I hope its just a "bad" patch, but I'm not exactly flush with cash at the moment so unexpected expenditure just means I will have to put off other items I wanted to do like the exhaust and engine rebuild  :cry: .

Maybe I'll feel better when my MX-5 comes back from being repaired, although that also seems to have a few ignition woes at the mo - hoping a new set of HT leads will cure that one….. classic cars eh? Great when they are running, absolute pain in the derriere when they are not! I wouldn't mind if I had a nice big warm double garage to fix this stuff in, but I have a tiny garage that I can't even get a car in at the mo, so most of this has to be done on the driveway, and the weather is quite frankly crap at the moment.

Cheers,

Chris

My little 'test' will tell you if you have fuel to each injector - should be an equal amount within 15% (revising the blurb to show bottles marked with 85cc and 100cc - if, in the test, one is filled to 100cc the rest should be the same, but not be less than 85cc - if you see what I mean).

Have you got a lift pump in the tank (lift rear seat, remove the circular plate - undo the pipes and remove wiring plug and undo the sender unit. The pump, if fitted, is attached to this, easy to change and only about ?27). There should be a small filter on it too (mine had 'fallen' off when the tank was changed)

WARNING - DON'T SMOKE and USE A BIT OF WOOD TO RELEASE THE SENDER UNIT.

When mine went it would start after a while, but was a bitch to keep going, no guts and kangarooing all the time - even with a full tank !.

Thanks Prowler - I'll check that out.

Cheers,

Chris

OK, spent a few hours poking and prodding around this afternoon, and to be honest I've not really seen anything to add evidence to the fact that its the fuel system at fault as I originally thought  :?

Pulled the sender out from the tank and it doesn't look like the later golf's like mine have a pump in there. On mine anyway there was just a ballcock like arrangement attached to the sender - no pump that I could see?

Had a good look around in there with a powerful torch, and to be honest it all looks pretty clean in there - not much in the way of any dirt / debris that I could see.

I also got under the car and had a good look at the filler neck and this looks to be very sound, and probably been replaced in the last few years. Certainly didn't see anywhere along its length that even looked noticably corroded.

The dizzy cap looks like its seen better days, and I have a set of quantum HT leads waiting to be collected from the VW dealer.

Half of me is thinking that maybe now is a good time to overhaul the ignition system and replace some of the (what look like) original components.

Is there any chance this could be the coil on its way out? I was thinking of replacing dizzy cap and rotor, HT leads, and coil as all look original.

I also though while I am at it I may as well do the fuel filter - is there any way of checking to see how much if any crud there is in there without splitting it open? Also do I need new washers / sealing rings if replacing this?

I think if I overhaul the ignition and the fuel filter then I will have eliminated some posibilities.

Tried starting the car a few times this afternoon, and its similar behaviour to last night. Starting from cold it runs fine for about 5 mins or more, then it just dies - no stuttering or misfires, just stops. If I then restart it it ran fine for a minute or two and then the same again. Third time I started it same thing - starts fine, then just dies after a short period of idling.

After this it just turned over and refused to start at all, and thats how I left it.

Anyone got any other suggestions for tests I can do to identify the cause of the problem. Should I be squirting carb cleaner anywhere to try and see if it cleans something out that is sticking for example?

If the replacement ignition bits and fuel filter don't do it then I will get some replacement injector seals and the next step will be to try Prowlers injector tests. Aside from that I'm stumped. Really hoping its not something like the metering head……

Cheers,

Chris

Chris,

It really worth reading one or both of1the two books on the bosch K-jetronic systems - it really helps with diagnosing and understanding the system.

The metering head can be removed and cleaned.  The only real way of testing the system is with a fuel pressure gauge (thinking of having a few made up), a multimeter and prowlers bottles.  With this it the system can be fully diagnosed and tested.

Mine won't start at the mo - I'm suspecting cold start issues - 5th injector, temp sender…

If yours is not a spark issue (I would not rule out the coil) it likely means that the mixture is probably lean - the only cause of this is a vacuum leak, restriction in airflow to the metering head, the metering head movement is restricted or fuel starvation….i.e. quite a few things!

Probably not helped much..

Strange that it happens after 5 minutes, unplug the auxiliary air valve and then start the car and see what happens, that closes fully after something like 5 minutes

Thanks Rich and Storm.

I'll try unplugging the aux air valve - is this the same as the cold start doobrey on the front of the block? I'll check the Haynes. I'm guessing if it runs OK with the air valve unplugged then its almost definitely a mixture related issue?

I'm pretty sure the vaccum hoses are OK if for no other reason than I replaced many of them just after getting the car. Maybe I should take the metering head off and give it a good clean anyway.

Chris

I had the same problem a few years ago, found out the fuel did not have enough presssure at idle. Renewed the fuel pump and the accumulator and it cured the problem.

Oh I forgot to add that the engine stalled on the motorway but after cranking it over many times the engine restarted but cut out on idle. My guess is the fuel pump is on it's way out.

Fuel pump sounds pricey, so I'll start with the cheaper stuff  :wink:

I had planned to replace most of this stuff anyway, just not all at once!

Chris

You can take off the fuel pump and test it in the kitchen sink, connect it up to a car battery and run water through it. My old pump was spluttering and noisy, very easy to test.

ChrisB wrote

I suffered a similar problem to Markwon with his fuel system

Sorry didn't fill you in with what happened in the end. I gave up and took it to a local garage. They checked through everything and decided that the problem might lay in the fuel metering head. After a bit of losening, fiddling and retightening they got it to fire up. This is great one hand, but on the other gave them nothing conclusive as what was wrong and whether it will reoccur.

Am going to get hold of a spare second hand metering head as backup. Out of interest dud ring Eurocarparts to see if they could still get a new metering head. Amazingly they were able to get a genuine Boich reconditioned unit for my 1600 EG engine. Only thing is it costs ?400  8O plus your old head in exchange.

Got car back now, seems to cold start better than before, cold start idle is stronger. However, seems to be a bit juddery (as though its missing occasionally) on warm idle. Every time you blip or load the throttle it clears and the engine picks up nicely. Car drives fine, engine pulls strong and cleanly across rev range, so may just leave alone at moment. Maybe best to get a Bosch diagnostic service?

Ouch - ?400 exchange. I'll be hoping that doesn't need replacing!

Is it possible to strip them down and renew / replace individual components in the metering head do you think?

Not sure how complex the metering head is - better check ETKA and my Haynes to see if there are any user servicable parts. Many moons ago I completley stripped, rebuilt and serviced the twin SU carbs on my MGB which was a very fiddly job, but eliminated a lot of fuelling problems and only required a service kit which was not that expensive.

Anyone know if the metering head off a Mk1 1800 DX engine appeared on any other VAG cars of the same era?

Cheers,

Chris

Metering head parts are not interchangeable due to such tight tolerances as the parts are matched.  You can take them apart for cleaning I believe.  There is only a couple of moving parts, diaphragm, metering piston and pressure valve.  There are a few O rings that could be replaced I expect.

Guy at Euro Car parts seemed to think a lot of the ?400 cost was to do with the fact the units have to be sent of to be serviced by Bosch in Germany, and that theres obviously not big demand for them nowadays.

In theory should be able to service one as long as the main casing is sound. I'm going to get hold of a couple cheap secondhand ones to rebuild/cannibalise. Might be worth contacting Bosch Service garage to see if they can source any parts?

Phew, sure glad i bought mine when i did, something like 125 euros shipped for a new bosch item, just keep your eye on ebay.de  :wink:

I've noticed that there are plenty of Audi metering heads in the scrapyard, you will probably get one for a tenner.

i'v got a spare sitting around in the garage if your intrested  :wink:

Ah Pirelli - you da man!  :wink:  Is the one in your garage known to be off a runner or of unknown condition? Does it look sound and is it off the 1800 DX engine?

I am now thinking it may be worth my while trying to scrounge a car to get up to meet you to collect those other bits. If I can clean up / service a spare metering head for not a lot of cash it could be a good way of identifying if that compnent is the one at fault.

Storm - do you have details of the ebay.de seller that you got the new 125 Euro metering head from? Failing that do you still have any details on what they are called in German so I can setup an alert on ebay? I have bought from sellers on ebay.de before so thats not a problem. For that money the peace of mind of a new unit would be worthwhile.

I had planned to replace most of the ignition / fuel system anyway as part of the ongoing restoration - just not so soon!

Cheers,

Chris

This is a subject close to my heart as I've just stripped and cleaned/overhauled a fuel distribution head as a spare for my 1800. The only real part to worry about is the pressure control valve that is accessable from the outside. This is available from VW for around ?45. As I have just found out the hard way do not split the fuel distribution head at the horizontal joint. I thought I had torqued the 8 screws back to a similar setting only to find the unit leaks when fitted to the car :cry: I can only assume that the 2 halves are somehow pressed together and then the screws tightened down. I'm going to investigate this more.
I have found a site  http://www.bba-reman.com/ that lists an item for the 1800 engine as ?125 + vat. A lot better than the ?400 dicussed.
The Bosch part no. from my unit is 0 438 100 100. This is the same as the part no. on my spare item. Search the above site for this no. and you will find it is also listed for the Audi 80.
I managed to get some new copper seals from a Bosch service centre for pence.
I also have an item I think is off a 1600 engine. Can anyone confirm the Bosch part no. :?: