running problem any ideas

[69 panel porn]

ive been havin this on goin prob for a few months now and struggling to gert to the bottom of it and if i cant find it soon its goin to some 1 to be sorted but cant really afford there price

its a 1641cc with twin carbs with electronic ignition

ive changed the fuel system (pump reg lines and flushed the tank out)
changed the distribuator and had it timed
changed the spark plugs and checked the ht leads

once ive got the van started (bit of a struggle when cold) it pops alittle once started wen hot,
it ticks over ok and rev ups ok but will pop and bang some times onced reved,
ill hold the revs up alittle bit in the engine bay by the cross bar which links the carbs and it feels like the engine jolts every other second think it sould do that but not sure and when im sat facing the engine with the revs up abit and the left carb coughs abit what could that be?
i drove it to just down the farm track and its driving like its got a power shortage then with out pushing the peddal and harder it pick ups on its own

can any 1 help me please im struggling with only a little knowledge

 

[moler]

When was the last time you checked and set the tappets?

What twin carbs are you running?

 

[Oslo_mark69]

could be a couple of things but as previously quoted check you tappet clearance as it could be the exhaust valve open as a result a tight tappet

It could also be that you have Air entering the combustion chamber below the carb , so check the gaskets and the manifold for cracks around the cylinder . If you rev it you should be able to hear or feel cold air on the back of your hand.

Also check that you dont have any leaks or holes in your exhaust system

 

[69 panel porn]

could be a couple of things but as previously quoted check you tappet clearance as it could be the exhaust valve open as a result a tight tappet

It could also be that you have Air entering the combustion chamber below the carb , so check the gaskets and the manifold for cracks around the cylinder . If you rev it you should be able to hear or feel cold air on the back of your hand.

Also check that you dont have any leaks or holes in your exhaust system

thats my next plan of action to check the valve clearances, (i dint think that would make that much of a problem but im gonna check it asap)
well i checked my carbs today and 1 has worked it way lose as it was a half a turn to tighten so did that up, and i can hear the air getting suck in,
im thinkin of rebuilding my carbs if i cant sort this problem out, as im getting worried it wont be running for my hoilday,
the exhaust seems to be fine as its pritty new
thanks for ur replys is there any thing else it could be

 

[crede999]

if its hesitating/popping/farting could possilbly be the coil , try another (borrow) my mate had a similar problem and it drove him mental he rebuilt his carbs 5 times eventually we tried an old coil and she ran like a dream ........(he did have a brand new flamethrower :shock: :shock: )

worth a go hope this helps

chris

 

[69 panel porn]

if its hesitating/popping/farting could possilbly be the coil , try another (borrow) my mate had a similar problem and it drove him mental he rebuilt his carbs 5 times eventually we tried an old coil and she ran like a dream ........(he did have a brand new flamethrower :shock: :shock: )

worth a go hope this helps

chris

i thought it was the coil a few weeks ago but some 1 on here said it wouldnt be, but i think its worth a go i dont no where i can borrow from to be honest ive seen a few lucas 1s for sale but no sure if there any good,
whichs 1s are good to buy if it comes to that?

 

[crede999]

just go to your local motorist shop and see what they have thats what we did, we actually tried one off an mg to see whether it was the coil , once we realised it was ,took the dodgy one to shop and got like for like (in a german voice ) bosch is always good yah

chris

 

[69 panel porn]

just go to your local motorist shop and see what they have thats what we did, we actually tried one off an mg to see whether it was the coil , once we realised it was ,took the dodgy one to shop and got like for like (in a german voice ) bosch is always good yah

chris

ill try my best german voice :lol:
will it make any difference that im running electronic ignition? mines a blue bosch at the min :?
thanks for ur help and ur time real appreciate it thanks sam

 

[69 panel porn]

just go to your local motorist shop and see what they have thats what we did, we actually tried one off an mg to see whether it was the coil , once we realised it was ,took the dodgy one to shop and got like for like (in a german voice ) bosch is always good yah

chris

ill try my best german voice :lol:
will it make any difference that im running electronic ignition? mines a blue bosch at the min :?
thanks for ur help and ur time real appreciate it thanks sam

and is it a ballast iginiton or not im getting so :?
or how can i tell wats on mine
thanks again

 

[crede999]

Shouldn't make any difference running elecy iginition ,my mate was running petronics elecy ignition at the time of his hesitation Popping farting

Good luck

Chris

 

[K@rlos]

Is it popping through the carbs or the exhaust? Carbs could mean it's running lean.

 

[69 panel porn]

Shouldn't make any difference running elecy iginition ,my mate was running petronics elecy ignition at the time of his hesitation Popping farting

Good luck

Chris

Ok mate I'll have to try that when I get home hopefully that will be it
Thanks Sam

 

[69 panel porn]

Is it popping through the carbs or the exhaust? Carbs could mean it's running lean.

It's popping and banging though the exhaust and every so often pops through the carb
I've check nearly everything I can think of to see if it's lean or not how do u think I could check it
Thanks sam

 

[alex4057]

sounds to me, like it's a leak in the exhaust system or carb set up to me.

 

[K@rlos]

Is it popping through the carbs or the exhaust? Carbs could mean it's running lean.

It's popping and banging though the exhaust and every so often pops through the carb
I've check nearly everything I can think of to see if it's lean or not how do u think I could check it
Thanks sam

Yeah sounds like it's running lean to me, what carbs are you running? Check for air leaks around all the gaskets by spraying wd40 or carb cleaner on the joints: carb to manifold & manifold to heads. Clean all the jets and check fuel pressure, could be a naffed pump or a blockage in the lines. It's just the process of elimination really.

I found my old Webers to be very sensitive to air leaks so I would start there.

Karl

 

[jonboylaw]

as above, sounds like an air leak to me. The WD40 should be sprayed on when the engine is running, you will hear a difference in the engine note.

 

[69 panel porn]

sounds to me, like it's a leak in the exhaust system or carb set up to me.

Ok mate I'll try this next i no how to test the carb by spraying WD40 from the carb to manifold
But how do I test the exhaust ?
Thanks for ur help and time sam

 

[69 panel porn]

Is it popping through the carbs or the exhaust? Carbs could mean it's running lean.

It's popping and banging though the exhaust and every so often pops through the carb
I've check nearly everything I can think of to see if it's lean or not how do u think I could check it
Thanks sam

Yeah sounds like it's running lean to me, what carbs are you running? Check for air leaks around all the gaskets by spraying wd40 or carb cleaner on the joints: carb to manifold & manifold to heads. Clean all the jets and check fuel pressure, could be a naffed pump or a blockage in the lines. It's just the process of elimination really.

I found my old Webers to be very sensitive to air leaks so I would start there.

Karl

I'm running dellorto DRLA 40s I'm gonna check all the inlet gaskets next and then I need to check the exhaust gaskets how do I do this?
If I find a leak I'm gonna rebuild them so I'll check the jets then, I've checked the fuel pressure and changed the pump and I have put new fuel line and filter,
I no it is elimination game ain't It just worried its something bigger that's all and it worries me

 

[69 panel porn]

as above, sounds like an air leak to me. The WD40 should be sprayed on when the engine is running, you will hear a difference in the engine note.

So it will change engine note if theres a leak do I spray it on the inlet then spray exhaust to see if that's leakin?
Thanks sam

 

[jonboylaw]

Sam,

Start the engine and let it settle to an idle, probably be a bit lumpy and rough. Once it is ticking over spray the WD40 around the joints between the carb and manifolds and around the manifolds and head. If there is a leak, you should hear the engine note change and it should run smoother as the WD40 temporarily blocks the leak. You should then be able to identify where to look.

Do NOT spray on the exhaust as you run the risk of causing a fire or at the minimum causing a stink!.
For exhaust leaks, carefully use the back of your hairy hand to feel the blowing, else use a length of hose pipe as a stethescope to listen around the joints etc..


Good luck mate.