Hi everyone, some of you may of seen my build thread for my Helios Blue Campaign. I have pretty much finished everything now but Im having trouble getting the engine to start, run or idle properly. My plan was just to get her to a drivable state so that I could take it to a specialist to be set up properly. But at *the moment I struggle to get it started. The engine is a 3A block, with a Late Cabriolet head (i think) part number on the head is 026 103 373 H, Im using an Audi 2.2 throttle body and WUR plumbed in to the vacuum system. I am using the k-jet injection system off the DX engine that originally sat in the car. Infact, everything on the engine apart from the aforementioned parts are from the DX engine. Where I could I have used new parts, such as leads, dizzy, rotor arm, plugs, all filters, new injectors with new rubber seals, all new seals and gaskets for the block, washers nuts and bolts etc! Everything that could be replaced without massive cost has been replaced. Timing is set up correctly following the guide on this forum. So it is currently set at 0 degrees as I have had no way to warm the engine up to set it to 6 degrees. And there is a good strong spark from every plug. When I try to start, engine turns over for about 20-30 seconds before even thinking about firing. Eventually it will fire but then it will be very lumpy and rough and will just stall unless I keep my foot on the throttle. It will not idle. If I allow it to cut out, its the same when trying to start it up again. Takes ages cranking her over for her to start, sometimes it wont even start. I decided to try and warm the engine up a little and see if it would run better as it has just been rebuilt and may need to be run in a little?! So I kept it running with my foot on the throttle for about 3-4 mins before I decided to slowly let foot of throttle to see if it would idle. It didn't. It cut out straight away. But upon trying to restart it, it fired first time of the key idled for about 1-2 seconds and then cut out again, I tried this a few times but it kept doing the same, idling for 1-2 seconds and then cutting out, it wouldnt even let me rev it up. By this point I noticed that the fuel pump had become noisier than usual, a mate said that it may be low on fuel, which it was, so I chucked in another 5 litres of fuel after about 20 mins and tried again. This time it went back to its old tricks... Taking about 20-30 of cranking before it would even think about firing!*:'(When I pulled the plugs out, this is what I saw.... Very wet (petrol) with carbon like deposits. So I assumed that it was probably running rich, so I adjusted the CO screw anti-clockwise to lean the mixture a little. This had minimal effect. Car doesnt even fire now! I made sure that the cylinders were not flooded when I tried to start again. So, ive got a spark, Ive got fuel and it runs (just about*:$) So where do I start to look to diagnose whats wrong with it?! I am fairly new to k-jet having always owned carbed mk1's before and only ever owned 1 mk2 16v with k-jet which actually ran like a dream so I never had any issues with it, thus, didnt learn much about k-jet! All other VW's have been DigiFant. So Im a bit stumped. Im sure its something simple, but I really have no idea where to start looking?? Flap in metering head moves freely, I know that much!*:thumbs:*And was fully cleaned before being re-installed. Any info on how to diagnose my problem would be greatly received!! Many thanks for your time, if I have missed anything that may help you geniusus please let me know!!*
My first thought is that you've got an air leak somewhere, maybe being compensated by the rich mixture. Have you double checked that the inlet is on tight, all the air pipes are connected, and the hoses aren't split. What idle control system are you running. Standard AAV and pipework, with no additional idle boost valve? Have you had the metering head in bits at all? Do you know if the metering pin under the fuel distributor is moving freely?
Hi Mike, thanks for your reply. I had thought about an air leak, but I cant hear anything anywhere and Im not sure on any other way to check for air leaks?! Apart from looking and listening! Inlet in on tight, with new gasket, all new vacuum lines and where old ones have been used new clips have been put on and all hoses and valves have been thoroughly checked. The idle control is buy the Aux valve I believe? The one behind the inlet manifold with a little two pin black plug, the valve is connected to the vacuum system. I have not checked this is working properly yet though, so could be a good place to start. No additional boost valve is fitted either, at least I dont think so, Im not sure what that is lol. The metering head has been in bits, when I cleaned it and painted it, only exterior paint :-D, the flap was moving freely, but I didnt check the plunger at the bottom of the fuel distributor, perhaps this could also be a good place to check?? How do I know if this is working properly? The one thing that ive discovered today though, which im not sure if it will have any bearing on the idle and starting is, the cam timing. After going through the motions and double checking everything today, I started with a compression test, came out fine on all cylinders with a max difference of 25psi between cylinders. Then I moved onto the timing, I noticed that the cam timing mark was lined up with the edge of the rocker cover and not the edge of the cylinder head itself, so this would indicate the cam timing was out by about 4-6 degrees?? Could this be the cause of all my problems?? I didnt have a chance to put everything back together today but will try and finish it off tomorrow and get everything timed up properly, if it works, brill, if it doesnt Ill move on to the next item to check!! :s Thanks in advance for your help!!
With an air leak, if you spray WD40 or Carb Cleaner on the joins, then the idle speed should rise if there's a leak. Check all the jubilee clips and joints in servo pipes, etc, are tight. The one round the back of the inlet manifold is the one that normally gets missed! The metering pin should move smoothly up and down, taking a couple of seconds (ish) to drop back down on the spring if you push it up.
Thanks again mike for the reply. Your going to laugh when you hear what was wrong!! I had bought a brand new old stock, and I mean about 10 years old, ramair air filter. For some reason the oil had actually clogged it up so much that no air would pass through it! So it was just chucking in loads of fuel without hardly any air!! Hense the black plugs. Anyway, she's all sorted now thank god. Thanks again for your help.
