Hello, can anyone help me out on what to start looking at here? The car runs great, starts great, maybe it runs slights (very slightly) a little lump now and again on tickover. I drove 260miles yesterday the car runs really well until i stopped at a services. When i started it back up it sounded like it was running on three. I checked my leads, all ok. Started again same thing, revved it up a little bit and it sorted it self out. It did the same thing when i got to my destination. Then i put it away. Ive had a bit of a search and cant find the same hot start problem? Any suggestions on where to start? Thanks alot Pete
Anyone any ideas where to start? I'm going to order some new plugs, leads, distributor cap, and a rotor arm today. They haven't really done many miles on them but its a start. I started it up last night and it was all ok. There is still a slight lump on tick over so i'll see if i can get rid of that. Is thee anything else i should change while i'm at it? Pete
this thread is a good place to start, just ignore all the 16v specific parts you dont have: http://www.clubgti.com/showthread.php?195423 ignition timing is done at idle with the vac line to dizzy disconnected and plugged, idle and co just done at idle. this thread has handy pics of the 8v camshaft markers: http://www.clubgti.com/showthread.php?124949
Cheers Jonny, So.. ive change the leads plugs and dizzy. she run's great. I'm pretty sure its not a timing issue. You wouldn't know anything was wrong it would run great all day. it's when its hot and you urn it off, when you start it up again when its still hot its like its running on three. You have to sort of rev through it for a while then its running great again, as before with no issue.? but that period of running on three doesn't sound good.. Any ideas? Pete
It could be losing system pressure somewhere Or one of the injectors is leaking a bit after it's shut down
hot start issues often caused by residual pressure problems, this is held by the non-return valve in the fuel pump. a holed fpr diaphragm can also cause it, if you take out the small screw in the end of it and fuel comes out theres the problem, assuming its not too rotten. or a fuel leak in the main line, but you would soon know about it if it was that! if the system cant hold pressure the fuel vaporises in the fuel lines giving you poor hot start till it clears itself
Thanks guys!, This sound's like a good thing to look at. So would you say first thing to check is the fuel pressure regulator diaphragm? Do i check this by pulling off the air pipe and waiting to see if any fuel comes out? or taking out this screw? i cant picture it. i'll have a look at it tonight. Cheers Pete
no thats the cold throttle enrichment valve. the fuel accumulator is under the car next to the fuel pump, its got 2 fuel lines on the same end. on the other end there is a small flat head screw, but if its rotten you may not be able to get it out. but if you see its wet with fuel thats another clue. the non-return valve is screwd into the fuel pump, its the fitting where the pipe attaches. now available from classic parts: http://www.vwheritage.com/vw_act_vwclassicParts.search.htm?classicSearchText=893906093 trouble is it may be pretty grotty under there so a chance the fuel pieps snap as you undo etc. HEL used to do a kit of parts, if you do decide to mess about under here be sure to repalce the 3 screws that hold the pump into the housing as they rot and expand, then crack the casing which is now NLA. the rubber mounts love to snap in half too so try to avoid undoing em if you can help it! they are available though if you need them.
Is the screw circled? and the non-return valve the one with the arrow going to it? So if it is leaking, replacing the non-return valve should stop the fuel getting through? Is it worth replacing the whole accumulator? I'll have a good look and order some parts before i start taking anything apart. What does NLA mean? Thanks a lot Pete
aye the accumulator screw is circled, the non-return valve is in the end of the fuel pump which is the bit in the middle bottom inside the plastic box if fuel comes out the screw hole in the accumulator, its bust and needs replacing. if not then the non-return valve in the pump might be the problem. the trouble with kjet you have to make educated guesses if you havent got access to a pressure testing kit! mushy mentions the injectors could be leaking which is a good shout, for that one you need to pop them out to see, its covered in my 16v guide
Got it! Great thanks. I'll take a look at the fuel pump/accumulator and see what i can see, Then on to the injectors as mushy suggested. I feel like the fuel accumulator is a good place to start. correct me if i'm wrong. Thanks a lot for the help Cheers Pete
Ive just taken the screw out the back of the accumulator, and its bone dry. i ran the car for a while. and no fuel came out. would this be instant? cheers Pete
well the good news is its not the accumulator, which is a very expensive part new I'd suggest an injector check next, and just follow the general trouble shooting tips in the 16v thread if you havent already done so. Ideally you want to hook up some pressure gauges to check the system, control and residual pressures this will confirm if its loosing pressure or not, otherwise as I say just have to make an educated guess its the non-return valve!
Cheers Jonny, Right i'll have a read, see if i can understand how the basics of the injection system works. I've never looked at any part of the injector system before. Can i buy a set of pressure gauges? can you recommend any? Cheers Pete
you can either buy a proper kjet kit for much moneys or cobble one up yourself, you need to put it inline with the pipe from front of metering head to wur and put a tap after the gauge for testing the system pressure. keep that on the back burner for now, give the system a full checkup it may just be a leaky injector as mushy said
Right i think i've got my head around it.. i think I'll try a spray with some carb cleaner tonight. Everything else i want to dedicate more time to. Should the injectors and seals be replaced as part of maintenance? are they expected to perish over a time? Do the holders need replacing too if i end up replacing seals? if so how do they come out? Thanks a lot Pete
if they've never been done before as far as you know, now would be the time to get them swapped over, silly not to for the price of em while the injectors are out I'm not sure if yours have the air shrouding, if so theres an extra seal on the tip. if you look for a vacuum pipe between ports 3 an 4 this tells you if you have it or not (if there you do)
Cheers matey. I'd guess at them never being done. I'll have a look for the air pipe tonight. Is this the one with the air shrouding (top) and the one without (middle)?
