Backfire !

[Ralphy]

Hi all

I have just bought a 1987 VW T25 converted van, excellent condition, well looked after, bought it from a friend who has had no problems with it. I am new to driving very old vehicles and when I took it out for a drive last night I noticed that it was slightly juddery on acceleration and then was backfiring on deceleration. The engine is Aircooled and very noisy which I understand.

I was wondering if anyone had experienced this, whether it was something I should get looked at, and whether there are any hints and tips for driving one of these ? I was told I should rev it quite high before shifting up ?

Anyway, any hints would be greatly appreciated !


Thanks
Nick

[BOXY]

I think they stopped making Aircooled T25's in 1983. Has yours had an Aircooled engine put in a later van.

http://en.wikipedia.org/wiki/Volkswagen_Type_2_(T3" onclick="window.open(this.href);return false;)

[Ralphy]

possibly, not sure

[kevtherev]

Does it have a radiator or not??

Backfire on decel is classic air leak on the inlet side.
other contributors are holed exhaust, timing and mixture.

As for revving it high theres no point.
Most of the power is at 3500 rpm.
Flat fours are not noisy engines when running correctly.
Rusty old exhausts are though.

[Ralphy]

Thanks

It has a water inlet for the engine so can I assume it is watercooled rather than Aircooled ?

Took it out for first drive last night - had window open so could hear the engine - when I say noisy, its sounds a lot different to my previous newer cars...didnt sound like an exhaust problem.

I suppose my question is do I need to be taking special care when driving it ? Do I need to ensure that is fully warmed up before I accelerate hard, do I need to be less agressive on accelerator in general....and what are the main things I need to pay attention to upkeep wise ?

I am a novice but hoping to learn quickly !

Thanks again

[kevtherev]

Does it have a radiator or not??

newer cars will sound different because they haven't got a flat four engine that's twenty odd years old have they?
plus if the tappets have drained then it will sound like a can of nails, add to that the old alternator bearing row, mains rumble, piston slap, valve train clatter and exhaust racket.. you have a genuine VW

If you service it properly then there's no special treatment needed.
Your wallet will determine how hard you press the accelerator... when it gets down to 12 miles to the gallon as opposed to 22, maybe you'll think about driving it easier and with less stomping on the brakes and acc. etc

Be diligent with
twice yearly service (oil and filter)
airfilters
coolant changes
keep an eye out for leaks and remedy them asap. (oil and water)

lastly although rust is not a crime it will be beavering away in your van some where trying to revert it back to it's original state when it came out of the ground ...Iron oxide
address it asap also

But mostly.....enjoy your van

[uniB]

Does it make a sort of popping noise when you take your foot of the accelerator? If so you've got rust mites in your exhaust system. It's reasonably easy to tell if there's holes, or if the joints between the sections have come away - leave the engine running and pop your head underneath - put your hands near the joints - you may well feel exhaust gas coming out of them. If the fault is in the intermediate sections not so bad - bit of grinding and section replacing (turn the engine off first though! ). If it's where the exhaust and engine become one, you're not so lucky.

As the engine are reasonably noisy anyway compared to a modern day car you might not notice the exhaust blowing noise amongst it's other sounds, particularly if you don't know what it's s'pose to sound like!

Guess it may also be dirt in the carb that's making it backfire - I think you'd notice though because it'd be running like a dog!

[Ralphy]

thanks for these suggestions, much appreciated.

I havejust come back home to have a play around with the van and although I can get it started if I keep my foot on the accelerator, when I take it off it is stalling straight away. Coupled with the other problem I mentioned earlier does this sound like I need to get a man out ?

[kevtherev]

If you don't know what an idle speed cut off solenoid is ...then yes.