mk1 running problems

[malmac]

forgot to mention, it's had timing light on it till all markings correct.

I didn't fancy messing with the tank as i'm not much of a mechanic, but if it's straight forward then suppose i could check that pick up.

Thanks again.

[Nate]

I've you checked engine timing or just ignition timing?

[malmac]

Hi, timing light went on right hand side of engine (looking from the front) where you unscrew plastic cap, was then altered by turning dizzy. As you can tell, i'm no mechanic.

Is there another part to check timing?

[Nate]

That's ignition timing - setting the point at which the spark fires. Engine timing isn't strictly adjustable, but can be wrong from incorrect fitting of timing belt. Just a case of checking that all the marks on the timing belt pulleys are lined up ok, and the belt is tight

[malmac]

ok thanks.

that'll be my next thing to cross off my check list, although i haven't experienced a simple fix yet to my teething problems, fingers crossed !!

[mark1gls]

Once you have checked all the engine timing marks, mark where the dissy cap is by the clamp, get the car warm, losen the clamp move the dissy cap anti-clockwise (To advance the timing) about 2 degrees with the engine running, (tick over speed might change) drive the car up the road and put your foot down in a high gear to hear any "pinking" keep adjusting the dissy cap anti-clockwisw untill you can hear the "pinking" then turn the dissy cap back a degree so the "pinking" stops, hopfully the car should be running better. If not you can always turn the dissy cap to were you marked it in the first place.
I borrowed a timing light to check my timing and I found using the timing light and setting mine to the book the car was a nightmare to drive, would bog down on pulling away, had to keep dropping down the gears going up the hills which before I did the timing was no problem, you had to keep the revs up to get anything out of it, so I went back to how it was before I set the timing to DTC. When I put the timing light back on you could not see the timing mark through the hole looking from above as it was that far over to the left if looking in the hole (could just see it if near the radiator!).
You will need a quiet road and if possible a slight hill to check for "pinking".

[malmac]

ok, that's worrying, i thought the timing light would be the most reliable method. Thanks for the advice. i'll have another go over the next few days.....

cheers

[Nate]

Timing light will set it "by the book" and it will give you a good baseline to work from, but as engines are different they will resell d differently to the above method (which is what I do)

you can usually advance the ignition timing quite a lot past the book value, although some engine will be right at that point. Fuel will also influence it to some extent. Set it up running on optimax type stuff and it'll run badly on cheapy fuel.

[Nate]

I should also add that I set these up on standard cheap unleaded, and don't think the extra you get from the expensive stuff is worth the extra cost

[MikeH]

If the car has been stood for a long time, then it could be a few things. How many miles have you done in it since you got it running? I don't subscribe to 'old fuel' stopping a car from starting unless it's several years old.

If the car has had a rusty filler neck, then it could be some of the fuel system is clogged up, but I'd expect that to cause a problem after 10-15 minutes running, rather than just hot starting.

It might be worth getting the fuel pressure and control pressure checked, especially if it's been rebuilt using a combination of bits from different cars. Has the mixture been checked on a gas tester? Has it got a CO reading from an MOT, since you got it running? There are a few other things you can try before resorting to specialist checks though.

Basic stuff that might give you a clue...

What colour are the spark plugs - Black and sooty, sandy brown, or slightly 'blue'? Do the electrodes all look in good condition and the plug gaps look right? Are all the plugs the same colour?

If the car is struggling to start when hot, take the plugs out - are they bone dry or wet with fuel? Not starting when hot would suggest it's too rich, but depends if all the bits of the fuel system are working properly.

I put a car together from 'bitsa' different fuel systems, and it took a surprising amount of fiddling to get it running right. Lots of metering head stuff. Trying a 'quick change' of metering head might create more problems than it solves.

[malmac]

Hi,

Thanks for your reply, not sure where to start.

The car was sat for around 5 years before it was completed but when i first got it i drove it till the MOT ran out and i seem to remember it had the same symptoms so i don't think it's old fuel causing the problems.

Took the plugs out, didn't think there were too bad, all the same brown colour, slightly sooty, gaps all the same. to be honest i didn't check them after the hot starting problem only when it was cold so maybe worth another look.

I'd say fuel pressure was good as cracked fuel filter after being tuned off for 15 mins and got a good squirt of fuel, i've had no CO check.

The engine is all original, it's only the body that's had parts changed.

Problem is i'm not that handy with cars, can change oil & plugs and other basic stuff so i'm still learning with it, thank god it's a straight forward engine.

I might take it to my local garage to see if he could do any basic checks like you've suggested to see if they can shed any light.

thanks again for your help.