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Thu May 18, 2006 1:49 am

After driving for a while(20mins) at 60mph my van will lose power until it comes to a crawl. If I pull over and wait for ten mins all is fine and away we go again. Even if I coast down a hill it picks up again. It seems worse when the tank gets to half empty. I have cleaned the gas tank, cleaned the carb, replaced the fuel filter, etc. Fuel pumps next. Its a 1600 twinport with petronix ignition eberspacher. Mike

Thu May 18, 2006 2:17 am

Well... the first thing that comes to mind is overheating...... are you in a hot climate?.... it is possible that its getting vapor lock... but usually vapor lock causes the engine to stall out and makes for hard starting...... but your problem sounds more gradual.... I am not sure what having only half of a tank would do??.... can you provide anymore info as to what happens to the engine.... does it seem like it is running hot? does it not lose power if you drive alot slower? and how long for then?.... whats the compression on the engine? what kind of shape is the third cylinder in? (seems that the third cylinder burns out easier than the others)... how many miles on this engine? is the fuel mixture leaned out a bit to much? (Im not positive, but I think if the engine is running lean then it is running hotteras a result).....

any other info that may help...

kris

Thu May 18, 2006 2:56 am

Its not running hot at all. I can drive all day at 50mph. I would call the uk a hot climate. The last time it happend I stopped at a Gas (petrol) station and filled up,it drove ok straight away. I am thinking fuel stavation. I had a similar thing with a motorcycle I took it in for a service and they set the float height wrong it would go fine for a minuite then lose power. Mike

Thu May 18, 2006 4:24 am

Non-stock, non-vented gas cap?

Thu May 18, 2006 4:29 am

Vented gas cap no sign of vacumn. Twin progresive fitted over two years ago with no problems. I did have a fuel pump go bad on me last summer. A previous owner had fitted a fuel filter between pump and carb, not between tank and pump. Is there any way of testing a fuel pump? Mike

Thu May 18, 2006 4:35 am

So you can drive all day at 50 mph but after you get up to 60 mph and stay there it starts to die correct?.... and if its not heating up then I would think that its a tuning issue... the float may be off just a little so that the engine is burning the fuel faster than the float will let it in..... so when you pull over or let off of the gas quite a bit then it has time to fill the float bowl back up.... it may also be a jetting issue.... but more likely float not correctly set....

is it a stock carb?

your question may also be better directed to the performance/ engine category.....

kris

Thu May 18, 2006 6:12 am

When you pull over and wait do you leave it running or shut it down. If you leave it running ...check your fuel pump, or just replace it. Sounds like it's a little slow and gets behind when you reach a certain speed. When you coast down hill the engine uses less gas and the pump catches up a bit. just a guess. let us know. By the way you can test the pump by disconnecting the hose and pumping it into a glass. remember it ain't a fire hose. ..but, there should be a small strong shot of gas every stroke. I like to disconnect the coil wire so the engine does not start when my friend cranks it over , as I watch the pumping action.

Thu May 18, 2006 6:16 am

what is condition of any fuel filters? in tank,in pump,in carb, any added ones.if partially clogged may be leaning out or restricting at higher engine rpms.