got an issue i cant seem to resolve. i have a new 1641 twin port engine, runs sweet as a nut, starts on the button and has only done around 3000 miles from new, all the ancillaries are from my old 1600 unit. when we were driving home from TLB summer camp the other week it started playing up, driving as though it was running low on fuel, coughing and spluttering. i pulled over after about 5 miles at my sister in laws house and it stalled, and would not start. i let the engine cool down for about an hour and then went out to have a gander, but again it would not fire up. i then would through the usual methodical checks, i had power, i had spark from the coil and on all 4 plugs, plenty of fuel, but still would not go. the leads and plugs were new when i installed the engine, as were the rubber joints on the inlet manifold which are still good. i checked the points, reset the gap, cleaned the faces, but still would not start. checked the fuel lines and filter, all secure and clean. then i had a cup of tea to re-assess the situation. when i returned to the engine bay i just looked at it to see if i could see anything obvious. it was then i notice that the lever on the right side of the carb, which is opposite and connected to the main throttle lever, was hanging off! bingo i thought, it had to be that. so i whipped the carb off, reattached the arm and checked inside, all clean and looked fine. i reattached the carb and it fired up, but only just, but it was running, but very intermittent, as though its was either over fuelling and causing back firing or not enough fuel and wanted to stall. anyhow i drove off again but the problem persisted so i pulled over after around 5 miles and called the aa, thanks cherished insurance mr aa man comes out but cannot see the fault, he goes through the same process as me but cannot find anything wrong. he then says, drive up the road and i will follow and then we will have anothe look at her. so off we go and would you believe it it drove perfect, not issues at all. so the kind aa man signs off the paper work and gets on his merry way. we then do the same and would you believe it, the problem returns straight away, sod it i thought i am just gonna keep going. i drove with this problem for about 35 miles, then suddenly it stopped and began driving normally again for the last 7 miles or so of my journey!! a real head scratcher i know! so i decide to take her down to beach buggin in portsmouth today, drove there fine with no problems at all, but then driving back home again just now it develops the same fault, like its being starved of fuel or maybe even over refuelling. please help me, all i can think of now is theres a problem with the carb somewhere, should i just buy a new one? its a standard solex 34 pict 3. thanks for taking the time to read my rantings, any ideas or thoughts would be greatly appreciated .
I'm assuming the AA man will have looked for sediment in the carb, so sounds a lot like gunge in the tank. You get a blockage in the outlet as sediment gets sucked towards it. Leave it a while and the stuff disperses. You may be able to tell if the fuel is getting starved by looking at the filter. An engine out job if it is the tank I'm afraid .
hi mate, the carb was nice and clean, both aa man and i had it off and all looked very clean with no debris. i also checked the filter from the tank and this too is very clean as is the fuel in it. the strange one with this is that it ldles fine, there is no sign of fuel issues then at all, it is when it goes under load it seems?
A few questions from me sorry..... Have you tested the fuel cut off solenoid? Does it click on and off when you touch the 'live cable to it' Is the fuel pump (new/old) standard not electronic? Is it the old style with gauze filter or fully sealed domed type? Pop the pump off and test to see it pumps fuel. Even though you say the carb looks clean - you dont need a lot to block up a jet etc etc. You say the arm was hanging off? Thats a worry - what else is loose? Recheck. Take the air filter off, pull the lever down on the carb, as though your accelerating (engine off) does the fuel shoot down the carb through the J shaped jet in the Venturi chamber? If not carefully pull that jet out and blow it clean - no bits of wire please. Pop the top of the carb off and check the float chamber - especially the fuel cut off valve, clean it out. Last thing if its a standard dizzy - pop the cap off, take rotar arm out, look down into the base and move if round (as though the vac pipe was moving it when it accelerates) is the Earth strap cable ok? Check its held on well and no break in the cable. Hope this helps?
Showing my ignorance of your engine, as I don't know how easy it is to get to the plugs, but have you checked the plugs? Have a look at them when the engine is misbehaving to get some idea. If dry and white running too lean, if wet and black, too rich. (over simplification I know but it might help give you an idea of the fuelling at the time of troubles)
thanks for all the replies guys. to answer a few of the possibilities: i have checked the plugs, all look good and have a nice reddish brown colour, reset all the gaps and they are all good. it runs a standard fuel pump, the sealed type, and i have taken the fuel pipe off the carb and put it into a clear container, and turned the engine over, and it pumps fuel through very nicely and evenly. my dizzy is a 009 but running standard points and condenser, all checked and all appear to be working fine. checked rotar arm and cap, cleaned all connections and all seem good. not touched the fuel sender or anything else that attached directly to the tank.as for the carb, the fuel cut off solenoid seems to work, it clicks as you suggested when i take off and put on the feed wire.i have yet to open up the carb and check the jets or float chamber, this will be next on my to do list tonight.i have a known good carb coming to me tomorrow so i will pop that on and check to see if it makes the diference. thanks for all the advice guys, karma awarded, hopefully i'll get it sorted
Nice one mate - good luck with it - I am sure it will be something simple so dont worry, you will find it.
You mentioned a 'lever' became disconnected from the carb. If you are running a stock solex 34pict3 then this sounds like the accelerator pump lever. It is conected to the throttle spindle on the alternator side of the carb. It's job is to provide a squirt of fuel when you put your foot down. It need to be adjusted correctly to provide a big enough squirt. To adjust you will need an 8mm spanner. To increase the input lossen the nut and push the nut and what it is attached to towards the fan housing. Only a small amount and then try the van. For full instructions go to vw-resource.com and type in accelerator pump adjustment procedure. Hope that helps - I had a very similar problem recentlly after a carb rebuild.
