BACKFIRE at end of holiday

[dave2878]

just back from a 900 trip round the north of scotland , van pretty much ran smoothly the whole time . in fact the only mechanical i had was the wiper arm coming loose when i was driving through glencoe on way home
the van is a 1985 1,9 petrol water cooled
i noticed a couple of times when rolling down a steep hill in 4th the engine slightly misfired, just a slight noise
then when i got home i revved the van high when it was out of ear and the exhaust made a fair bang
i am novice when it comes to engines and the likes so i am looking for a point in the right direction please,
i only saw two other t25 the whole time away . and 5 t2 and 1 splitty.was everyone in hiding


JUST SPOKE TO MY DAD AND HE TOLD ME ITS ACTUALLY NOT A MISFIRE IT IS A BACK FIRE

[jrt]

Afternoon, I've had a few similar problems over the years. Mine turned out to be[in order] leaking exhaust system, loose vacuum hose[carb] and then a knackered inlet manifold gasket letting in air.
https://club8090.co.uk/forum/viewtopic.p ... e#p8112114" onclick="window.open(this.href);return false;
Have a search for backfire/popping in the top right of this page, there's plenty to go at. I'm sure more help will soon be forthcoming.
David

[kevtherev]

i am novice when it comes to engines and the likes so i am looking for a point in the right direction please,

point yourself at a trusted garage, and tell them you have a backfire on the overrun.

[dave2878]

yes thats what my father said. he had a t2 for about 20 years so he says he will look at it, i also want to learn how to do these things,
so far i have managed to change the slave cylinder and replaced the pipes, also manged to do a fair bit of welding. so i am looking to try and do the work myself if its possible,
however as i said i am a novice, so do ye think it would be better idea to let a garage have a look,
i was going to change the spark plugs and air filter , and change the oil.

[Smosh]

You mean a backfire on an over run is a problem. Damn! I quite like mine!

[kevtherev]

i was going to change the spark plugs and air filter , and change the oil.

Oil should be changed twice yearly or every 3,500 miles, filters once, spark plugs generally last well.
I assume you know when it was all done last?

[kevtherev]

......I also want to learn how to do these things,

that's the spirit
google backfire on the overrun and you'll get a deluge of information
There are a number of reasons that causes it, and you have to eliminate them methodically.
Starting with the easiest
air leaks into the induction side, caused by perished vacuum pipes and misplaced vacuum pipes.

[dave2878]

thanks i will start looking tomorrow.and keep you up dated.

[dave2878]

i was going to change the spark plugs and air filter , and change the oil.

Oil should be changed twice yearly or every 3,500 miles, filters once, spark plugs generally last well.
I assume you know when it was all done last?

no unfortunatley not, i bought the van last year and i spent a fair amount of time trying to cut out rust i neglected the engine . i have a few days of in next couple of weeks so i will start running through all the things that i should be doing,

[kevtherev]

Then you should service this engine asap.
15/40 or a nice 20/50 mineral oil, any brand.
Mann filters
Brickwerks, cap, arm, leads and plugs

[Mocki]

15/40 mineral oil, ONLY use 20/50 if you have a worn out engine.

[dave2878]

done a wee bit of work in van mainly cleaning distributor cap and tightening all the bolts in the exhaust as a couple were very loose, this seams to have solved the back fire and the van sounds better when i drive it.
i have a new oil filter , air filter , spark plugs . fuel filter, so i am going to be doing these things hopefully over the weekend. also need to order a new radiator as i have a leak coming from that,

[a1winchester]

While you are at it, I would also recommend new HT leads, Dizzy cap and rotor arm. They may look ok, but it's hard / impossible to see the defects on these items. And if you don't know when they were last replaced, it makes sense to renew them.

[dave2878]

cool i will have a look at them and get them replaced. already got the rotor arm . what is the dizzy cap? thanks for the help people its appreciated

[a1winchester]

Sorry - Dizzy = Distributor (or how I feel after drinking a few pints of Old Rosie)