Starting problems after changing head gasket

[puddy]

8 hours ago, bigjohn said:

 

 

 

re- the symptoms seem more to do with not enough air rather than too much, it needs accelerator to go

 

 

 

Still sounds like too much fuel/rich mixture to me . Throttle butterfly wide open will introduce more air , thats how you start a flooded motor.

 

8 hours ago, bigjohn said:

 

 

 

 

 

2 hours ago, PatrickHarnett said:

There are sparks at all four plugs.

I cant see any obvious places where there could be an air leak. Plus it starts easier when the vacuum pipe is off! (introducing an air leak effectively)

 

True the plugs do not smell of petrol.

Like i said a couple of days ago taking the hose off is offsetting a rich mixture. I would check fuel return from the fuel pressure regulator , pinched fuel pipes , injector stuck open and hosing to begin with.

 

Cheers puddy 

[bigjohn]

8 minutes ago, puddy said:

 

Still sounds like too much fuel/rich mixture to me .

 

Possibly but I would expect the plug to smell of petrol if too much fuel - that's why I asked the question.

 

That's also why I mentioned the temperature sensor - as an experiment try disconnecting it and attempt to start it. The head gasket was obviously failing but my gut feel is this was not the reason the car stopped (although it's a good thing it's fixed now!).

 

Picture ripped off from another post:-

 

 

Edited 12 March, 2018 by bigjohn

[puddy]

If its trying to run then it will be burning most of the fuel off of the electrode. 

Best thing would be to read what the engine is seeing for throttle position and engine temp etc rather than guessing at it. The things i suggested were fairly easy manual checks. 

[PatrickHarnett]

I don't think so. There seems to be a temperature sensor in the thermostat housing, of course that had to be removed. I didn't see any other sensors. The Lambda sensor in the exhaust was also left in place untouched as I left the exhaust attached to the manifold.

 

[TMB]

What about the MAP sensor on the back of the intake manifold? Haven't disturbed the wiring or anything?

 

[PatrickHarnett]

This was disconnected when the inlet manifold was removed. It was reconnected when the manifold was remounted.

[PatrickHarnett]

OK,sorry to be some time in coming back to you guys with an update. Firstly a big thanks to everyone for your invaluable help its really appreciated.

 

I took the car to someone that has a computer. It was not as useful as I had hoped, but it did indicate that there was a problem on 3 and 4 cylinders. So we redid the tappets NOT following the procedure on the site  https://workshop-manuals.com/skoda/fabia-mk1/drive_unit/1.0/37;_1.4/44;_1.4/50_kw_mpi_engine/engine_cylinder_head_valve_gear/repairing_cylinder_head/basic_setting_of_hydraulic_valve_clearance_compensation/  but as I used to do it in the past on old-timers. It started and ran perfectly. It runs really nicely now.

 

I noticed that the head and rocker gear were disgusting with crusted on crap from old oil. Previous owner maybe never changed the oil or put some cheap rubbish in, despite telling me it had a service just before I bought it. (there is even a stamp in the book). I removed the sump and found the oil pump grille encrusted and partially blocked. Cleaned all that up, cleared the sludge from the sump and checked the oil pump and cleaned it all out. I replaced the broken thermostat and the defective oil pressure sensor.

 

I still don't know why it stopped running, though in a way its a good thing it did, as it forced me to get on with doing the much needed work on it. The car deserves some better attention than it seems to have had in the past.