No Start After Rebuild

[robwright]

OK finally got all of the parts together and the time to get the car finished off this weekend. Wasn't all plain sailing as it took two battery charges and a great deal of priming of the oil pump just to get pressure when cranking on the starter. However it cranks well but doesn't start [] This is what I have checked so far:

Compression seems good when cranking the engine by hand.
Fuel delivery at the end of the rail seems good.
My spark tester tells me that there is spark.

The only thing I can think of is the injectors. I think I can hear them clicking when cranking but I can't be sure they are ctually injecting anything. Short of pulling them and bench testing them is there anything else I might be missing? Any help appreciated. Had enough for today - battery is back on charge []

 

[Frenchy]

Rob the plugs would be wet if the injectors are delivering and the engine not firing, double check all sensor plugs, it will turn out to be something silly []

 

[robwright]

You are probably right mate it normally is. Hadn't got round to stripping the plugs out yet tonight. I can't think of it being anything else but the injectos TBH but the only thing that I did to them was remove them and fit new seals and filters to them [&:] If they worked before then logically they should work now. I might bring a bit of easy start home from work and give it a little sniff into the air filter. That would be definitive proof I suppose if it tries to fire.

 

[TTM]

Did you check the crank triggers? Height + plugged in the right connectors?

 

[944 man]

To help to narrow it down Id suggest indicator lights on the high tension leads / plus and a tell tale lamp on one or more injectors. The former can be bought from Halfords for around a tenner (Laser) and the latter would need fabricating yourself.

Between them you should at least be able to work out what was working and from that, hopefully, what wasnt.

 

[robdimond]

Rob, I was just wondering how you were getting on...
I can't add anything technical on top of what has already been said... but I hope it's something simple and good luck!

 

[PSH]

Hi Rob

Don't you just hate it when things like this happen, no fears though I'm sure you'll find out the problem soon enough.
It's a bit difficult diagnosing from afar and I'm sure you've already checked the most obvious. You say you have spark and fuel in the rail, you don't need to bench test an injector , you can just as easily pull one from the manifold and turn over to see if you have fuel and more importantly if it's atomising correctly.
Assuming that all is well with both fuel and spark I think I'd check the timing, is it possible that during the rebuild (which admittedly isn't the easiest of things to do while the engine is in the car) the crank was set 180 degrees out. The engine iirc would still turn by hand without hitting any valves and turn over by the key but of course she wouldn't fire up which seems to me what you are experiencing. Of course this is assuming that everything else is working fine?

Pete

 

[peanut]

if you have sufficient fuel pressure but no fuel delivery then the tiny solenoids in your injectors could be sticky with residue from the fuel detergents.
To free up the injectors you can disconnect the electrical connectors and using a 9vdc PP3 battery and a couple of bits of wire flash the injectors until you hear them clicking freely. they should self-clean once the engine runs. Make sure that you do not hold the battery on the injectors for more than a fraction of a second. You are aiming to simulate the ECU pulses to the injectors so just brush the battery wires over the connectors and you'll see a tiny spark and hear the injector solenoids moving.

ps if you have both a spark and fuel pump then the crank sensors and DME relay must be working correctly.
As others said you need to check your plugs for fuel and easy start should get it running