starting problems!
Turbo Mini Forums

got everything finished on my engine and fuel system today, tried to start it and it was firing occasionally, so i checked the compression, (1) 145psi (2) 135psi (3) 125psi (4) 125psi , the compression tester developed a small leak in the pipe on the last 2 cylinders.
so the compression is good, i then checked for a spark, weak all round, so i changed the coil, and it was loads better but still not 100% so i checked all the earths, one was loose, so i tightened it up, checked spark again, million times better!, there is fuel getting through as well because 2 of the plugs were wet, couldn't tell on the other 2.
tried start it again, no luck yet!

i am wondering if the fuel pressure is to blame for this? how can i tell what the fuel pressure is? what is it supposed to be at?
can anyone else think of what else could stop it from starting? the timing is set at the std marks.
plz help me on this one, i need the car done and on the road
thanks
steve

Compression doesnt seem that good i dont think, on a mg metro engine its supposed to be 200psi, anything less than 180 and its supposed to be on its way out. Turbo will be less but not that much less i wouldnt have thought.

Check the fuel pressure with a guage, supposed to be 3.5psi

gunson lo-gauge is a good one.

Don't get too hooked on compression readings... Use the gauge as a comparitive tool...

Even with a 8.5:1 CR, my gunsons gauge reads 180psi... Waaaaaay OTT!

Anyway, if there is fuel on the plugs, it is getting in there, so pressure is not to blame.
I'm suspecting the ignition system here - either timing or other factor.

I'm also assuming you're using fresh fuel?

Just remember, Until you reach 3000rpm, this is just a nat asp engine... Nothing special or different about it at all.
Hence if the engine is built correctly, the carburettor is functioning, and the sparks are occuring and at the right time, it WILL fire.

Yep it will fire even if the timing is a fair way out, even 180 degrees! it wont run but will fire

When trying to start an engine I take Dave Walkers advice.

If it does not start get some eazy start and squirt it into the carb while cranking. If it fires then you have a fueling problem, if it does not fire then you have an ignition problem.

I used this recently to decover that a needle that my brother had given me was for a larger jet and hence blocked the jet totally, meaning no fuel.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

If the fuel pressure is so high that the engine won't run, then usually if you remove the vent pipe from the carb (the one the solinoid goes to) then fuel can be seen coming out of it.

If this is happening, before you mess about with the pressure regualtor, check there isn't any restriction in the return pipe.
Don't assume that because you can see petrol going back to the tank that the pipe isn't restricted either!

i am going to try again today, the thing really seems like its got good compression, its got more than my old xr3i had! so i presume its real good.
i am just putting the timing back to standard marks and going to try it again, if no lunk this time i will be strippin the carb down and cleaning it all out, just to make sure.

got fuel coming out of my soddin float chamber breather now