Tuning

[Guest ashnicholls]

Hi,

 

As people may have seen with my other post.

 

I have just put my 1.6 with big valve head and twin webers in.

 

The engine runs. Although none of the sensors, such as temp sensors or fan work. And the alternator isnt charging.

 

The main problem is that it has a miss fire. We managed to get it running and idling when it was warm, but as I say it isnt running brilliantly, its abit lazy to rev and the carbs spit back every so often. It is also running hot which suggests the timing isnt right.

 

Does this sound like ignition timing. Or is it cam timing? I cant see it is because I used a vernier pulley and spent alot of time getting it accurate.

 

How do you read the ignition timing? As I have the hole where you would see the timing with a timing light in my gearbox. But I do not have a scale to read it against, am I missing something?

 

Could it be the carbs not being set up very well. Ie the idle screws and such.

 

Some technical help would be usefull.

 

And anyone in the Shropshire area that knows how to tune XU 8vs and Webers I would pay petrol money if they could come and lend a hand.

 

Cheers Ash

Edited August 14, 2006 by ashnicholls

[Guest ashnicholls]

what so no one knows how to tune the engine up?

[Guest ashnicholls]

Cam timing is spot on.

 

Where ever I put the dizzy it still seems to be miss firing???????

 

Carbs are just set to standard how it says to in the tuning book.

 

Cheers

[steve@cornwall 100]

Cam timing is spot on.

 

Where ever I put the dizzy it still seems to be miss firing???????

 

Carbs are just set to standard how it says to in the tuning book.

 

Cheers

 

 

Is it possible that with apparently nothing that is earthed to the block working properly, the problem is related to the earth strap to the engine?

[Guest ashnicholls]

How do you come to that conclusion????????

[Guest ashnicholls]

Just found the dizzy wasnt up to much, so cleaned it all out, replaced the vacuum advance for one that works.

 

and it isnt miss firing now.

 

But still sounds like a bag of **** and wont idle below 2000rpm.

 

It might only be me with it running hot, it has sooty plugs so its running rich if anything. not lean.

 

Anyone in my area fancy coming and having a play with the carbs?

 

Cheers.

[steve@cornwall 100]

 

The engine runs. Although none of the sensors, such as temp sensors or fan work. And the alternator isnt charging.

 

The main problem is that it has a miss fire.

 

?

[Guest ashnicholls]

Yes sorry ok, I didnt mean to sound rude, I was just curious how you came to that conclusion.

 

Alternator isnt working full stop. Taking it to be done today.

 

The fan isnt working, so wired up my old fan.

 

And my dad tried to bodge the old loom onto the new engine (1.1 to 1.6)

 

And he either hasnt got the right one, or the sensor isnt working.

 

Cheers

 

But if the engine wasnt earthed it wouldnt run at all would it??????

[steve@cornwall 100]

But if the engine wasnt earthed it wouldnt run at all would it??????

 

Was thinking more of a dodgy connection with high resistance rather than no connection- you didn't sound rude ,by the way . If faced with multiple problems I always wonder if there's a linking factor, no matter how improbable and go for the most optimistic, cheap and easy fix. It's an extremely low "hit-rate" but fantastic on the few occasions it works out. ( I had also overlooked the starter motor )

[mattmk1 0]

It may be your knackered alternator, as the longer the car runs the more the battery will drain, which will eventually lead to misfiring, a reluctance to rev and eventually the car will cut out and stall. how long have you had it running for, and is it recharging the battery at all? If not then it may well be alternator related.

[pugrallye 0]

with carbs, you must first have a good voltage supply and strong spark before you can go any further

[Guest ashnicholls]

Alternator is working now, battery is full.

 

It turns over fine no worries.

 

But now I cant get it to start at all.

[Guest ashnicholls]

Has good power supply and very good spark.

 

Right I have had it running, with standard timing it ran. But not very well, back firing and spitting out of the carbs. Even souned like it was missfiring. sounded like it was running rough, Suggesting cam timing????????? This is how it was when I first started this tread.

 

So I advance the timing 5degrees on the vernier, where the engine started to run better, not so much miss firing, and back firing and spitting. But was still spitting out of the carbs, and still didnt sound brilliant.

 

So I advanced it another 5 degrees. (well i think its degrees, it was 5 marks on the vernier. The engine then ran better still. sound much better. But it still occassionally spits out the carbs.

 

Whats going on and why would I need to advancing the cam almost 2 teeth on standard timing?

 

It is supposed to be a 1.9 gti cam, which would run on the standard timing holes? But could it be a slightly hotter cam needing more advance?

 

 

Also with the timing set to standard, when the webers were opened fully quickly the engine would stall,

 

But the more advance I have given it, the less this happens, Ie it doesnt stall as easily???????????

[SPGTi 2]

Ash,

 

If you can get the car down to Mick at Hi-Tech Motorsport in Cradley Heath I am sure he will be able to sort it out.

 

 

Steve

[Guest ashnicholls]

They know what they are doing with cam timing with verniers and webers?

 

Cheers

[SPGTi 2]

They know what they are doing with cam timing with verniers and webers?

 

Cheers

 

 

Yes Mick is very good with carbs. Most of his work now is setting up historic racecars. Just give him a call, explain what is going on and he will sort you out. no. is 01384561777. You can also stand next to him while he is working and ask loads of questions. Sometimes he can be a bit grumpy but he tells it how it is with no bulls*it. Tell him I sent you if you like.

 

Steve

[boombang 2]

Lol @ the grumpy comment!

 

If you do go down there ask him to tell you the story of the guy who was insistant on spraying fuel into the carb trumpets - he tells it perfectly

[Guest ashnicholls]

Lol @ the grumpy comment!

 

If you do go down there ask him to tell you the story of the guy who was insistant on spraying fuel into the carb trumpets - he tells it perfectly

 

Eh whats that then?????

[Guest ashnicholls]

Yes Mick is very good with carbs. Most of his work now is setting up historic racecars. Just give him a call, explain what is going on and he will sort you out. no. is 01384561777. You can also stand next to him while he is working and ask loads of questions. Sometimes he can be a bit grumpy but he tells it how it is with no bulls*it. Tell him I sent you if you like.

 

Steve

 

Yes ok,

 

Is he resonably priced.

 

Cheap would be ideal, ha.

[Owain1602 0]

If its spitting back through the carbs normally it because ignition timing is too retarded or because the mixture is too lean so some of the mixture is still burning when the valve opens.

I recomend that you put the cam timing back to where you set it up and adjust the idle mixtures, make sure you have them balanced spot on though. Have you balanced them?

[Guest ashnicholls]

Well I tried too. But I could never get the engine to idle and run at a constant revs to do so. It kept hunting and dying. And putting the balancer on, made a difference to this. I did it as close as I could though.

 

Cheers Ash

[Owain1602 0]

how many turns have you got the idle screws out? It gonna be impossible really to set the idle mixtures without a gas analyser.

you could try and richen it up a little see if they stop spitting but really you need to set your cam timing back to what it was and get a fair ignition advance really.

[Guest ashnicholls]

1 full turn out now.

 

And is running best it has been.

 

Will take it to someone who knows what they are doing.

[Owain1602 0]

you want to turn it out much more normally.

Generally you want 2 - 2and a half turns out and start from there.

[Guest ashnicholls]

Eh?

 

Why does haynes say 3/4 of a turn?????

 

So it needs more fuel?????

 

Why are my plugs all sooty then??????